blocks|key|112695|text|使用类路径'com.android.databinding:dataBinder:1.0-rc0‘|type|unstyled|depth|inlineStyleRanges|entityRanges|data|112696|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

use class path 'com.android.databinding:dataBinder:1.0-rc0'

blocks|key|112706|text|如果可能的话，我能想象的唯一一件事是如果你没有|type|unstyled|depth|inlineStyleRanges|entityRanges|data|112707|dataBinding+{
++++enabled+true
}|code-block|syntax|javascript|112708|在你的gradle文件中。如果不是，只需将其添加到gradle文件中。i.e|112709|android+{
++......

++dataBinding+{
++++enabled+true
++}
}|112710|然后同步您的项目。如果仍然失败，您可能需要对android+studio执行失效/重启操作|112711|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

The only thing I can imagine if possible is if you don't have 

<pre><code>dataBinding {
 enabled true
}
</code></pre>

in your gradle file. If not just add it to the gradle file. 
i.e 

<pre><code>android {
 ......

 dataBinding {
 enabled true
 }
}
</code></pre>

then sync your project. If it still fail, you may need to do Invalidate/Restart of your android studio

blocks|key|112716|text|我也有同样的问题。在阅读android+sdk文档后，只有预期的文件名需要创建，但没有说明如果没有创建，该如何处理。经过进一步的研究后，我注意到在像下面这样(使用您的示例)删除了布局元素的名称空间之后，它对我起作用了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|112717|++++<?xml+version="1.0"+encoding="utf-8"?>
++++<layout>
++++++++<data>++</data>
++++++++<RelativeLayout
+++++++++++xmlns:android="http://schemas.android.com/apk/res/android"
+++++++++++android:layout_width="match_parent"
+++++++++++android:layout_height="match_parent">
++++++++</RelativeLayout>
++++</layout>+|code-block|syntax|javascript|112718|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I had the same issue. After reading over the android sdk docs, there is only the expected file name to be created but nothing about what to do if it does not happen. I noticed after some more research that after removing the namespace to the layout element like below (using your example), it worked for me.

<pre><code> &lt;?xml version="1.0" encoding="utf-8"?&gt;
 &lt;layout&gt;
 &lt;data&gt; &lt;/data&gt;
 &lt;RelativeLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"&gt;
 &lt;/RelativeLayout&gt;
 &lt;/layout&gt; 
</code></pre>

blocks|key|2655863|text|自动生成的DataBinding类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2655864|如果您的xml名称为activity_test，则绑定类将为ActivityTestBinding.|offset|length|style|BOLD|2655865|但,|2655866|dataBinding+{
++++++++enabled+=+true
++++}|code-block|syntax|javascript|2655867|布局应以布局为根|2655868|<layout+xmlns:android="http://schemas.android.com/apk/res/android">
</layout>|2655869|entityMap^0|0|U|J|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@$D|W|E|X|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|Z|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|L|7|11|8|@]|9|@]|A|$M|N]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

DataBinding class generated automatically.
if your xml name is activity_test then the Binding class will be ActivityTestBinding.
but,
<pre><code>dataBinding {
 enabled = true
 }
</code></pre>
layout should have layout as root
<pre><code>&lt;layout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;
&lt;/layout&gt;
</code></pre>

blocks|key|2866839|text|在正确设置它(包括xml命名空间和将所有内容包装到<layout>中)之后，对我有效的方法是进行Build+->+Make项目。“清理项目”或“重建项目”也没有。我使用的是Android+Studio+2.3.1，使用的是26.0.2构建工具。不需要<data>标签。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2866840|entityMap^0|P|8|3H|6|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

After having set up it properly (including xml namespace and wrapping everything into <code>&lt;layout&gt;</code>), the one which worked for me was doing Build -> Make project. Nor Clean Project or Rebuild Project did. I'm in Android Studio 2.3.1, using 26.0.2 build tools. There's no need for <code>&lt;data&gt;</code> tags.

blocks|key|2655936|text|数据绑定类是在构建过程中生成的，所以在应用程序的Gradle构建中启用数据绑定并用布局标记包围xml之后，应该重新构建应用程序。如果这不起作用，请删除您的build文件夹，然后重新执行此操作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2655937|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Data binding classes are generated during the build so after you enable data binding in the Gradle build of the app and surround your xml with the layout tag you should rebuild your app. If that doesn't help, delete your build folder and do it again.

blocks|key|112766|text|我也有同样的问题。你所做的一切都是正确的。问题是您需要在xml中的data标记内添加变量。为此，您应该创建一个示例模型类，并将其作为变量添加到数据标记中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|112767|在此之前，您将无法看到生成的ActivityMainBinding。|112768|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I had same problem. Everything you done correct. Thing is you need add variable inside data tag in xml. For that you should create a sample model class and add it as variable in data tag. 

Until that you won't get to see generated ActivityMainBinding.

blocks|key|110328|text|在我的例子中，绑定类已经生成并就位了(但我认为它不是)……但它不会自动将所述类的导入添加到activity/fragment+import部分...所以..。OPTION+%2B+ENTER+:)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|110329|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In my case, the Binding class was generated and in place ( but I thought it wasn't) ... but it does not automatically add import of said class to the activity/fragment import section... so... OPTION + ENTER :)

blocks|key|112365|text|我没有得到令人满意的答案。下面是我对数据绑定知识的总结。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|112366|解决DataBinding问题的提示|112367|更新|112368|为了获得更准确的errors和suggestions，我强烈建议将Android+Studio和Gradle插件的版本更新到最新。因为在AS+3.2版本之后，我不会面临太多问题。|offset|length|style|BOLD|112369|请参见Latest+Android+Studio和Latest+Gradle+Plugin。|112370|原始解决方案|112371|112372|阅读此答案后，您的将不会在类和数据变量的数据绑定自动生成问题中卡住。|blockquote|112373|112374|112375|逐一检查这些要点。其中的任何一个都可以让你的工作完成。倒数第三点非常重要，所以不要错过它们。|112376|1.检查数据绑定是否启用|112377|您应该在build.gradle中启用数据绑定。如果不是，则添加此和同步。|CODE|112378|android+{
++++...
++++buildFeatures+{
++++++++dataBinding+true
++++}
}|code-block|syntax|javascript|112379|2.检查布局已转换为绑定布局|112380|现在，如果您希望生成数据绑定类，那么您应该使用数据绑定标记(+(<layout++data+binding+tag)进行包装。就像这样。|112381|<?xml+version="1.0"+encoding="utf-8"?>
<layout+xmlns:android="http://schemas.android.com/apk/res/android">

++++<android.support.constraint.ConstraintLayout
++++++++android:layout_width="match_parent"
++++++++android:layout_height="match_parent">

++++</android.support.constraint.ConstraintLayout>
</layout>|112382|同时检查绑定变量名是否与视图模型类中的一样正确|112383|3.自动生成绑定类名？|112384|您的数据绑定类应在创建绑定布局后生成。|112385|112386|如果您的布局名称是snake+case+activity_main.xml，那么数据绑定类将在驼峰大小写中生成，如ActivityMainBinding。|112387|112388|112389|4.看不到导入建议？|112390|有时，当您键入ActivityMai...，时，它不会显示suggestion，在这种情况下，。|112391|import+<yourpackage>databinding.ActivityMainBinding;|112392|5.阅读构建失败日志|112393|如果构建失败，将不会在布局中生成绑定类和新变量。因此，首先通过CtrlCtrl键和F9+(Build+>+Make+)来创建项目。|112394|112395|如果构建失败，那么看看什么是错误，通常我们在布局字段中会有错误。错误日志将指出错误行号，其中包含issue.|unordered-list-item|112396|Binding可能会失败并导致一些愚蠢的错误，如语法错误或缺少导入。在这种情况下，您将得到充满绑定类错误的logcat。但您应该阅读完整的logcat+to+find+issue.|112397|+(找到合适的日志|112398|6.从最近关闭和打开项目|112399|我总是这样做，因为它比Rebuild+/+Make项目花费的时间要少得多。|112400|112401|从文件关闭项目>关闭项目|112402|再次从最近的|112403|打开|112404|请注意，我更喜欢从最近的中关闭和打开，因为它比Rebuild/+Restart+花费的时间要少得多。|112405|7.重建项目|112406|如果仍然没有生成您的类。(有时当我们粘贴布局文件时，它就会发生)。然后从Build>+Rebuild重新构建项目(而不是Build或Make项目)。它将生成您的数据绑定类。(Rebuild为我变魔术了。)|112407|8.拥有最新的Android+Studio|112408|在更新了Android+Studio+3.2之后，我感觉数据绑定自动生成中的许多错误都被修复了。所以你也应该有最新的AS。|112409|#+<variables解决方案|112410|<data>
++++<variable
++++++++name="item"
++++++++type="com.package.Model"/>
</data>|112411|通常，当我们在布局中放置一个变量时，它会创建一个getter和setter。我们可以使用binding.setItem(item);和binding.getItem();，但是如果您看不到这些方法，请阅读下面的信息。|112412|1.从最近关闭和打开项目|112413|如果您已经在您的布局中创建了一个数据变量-+<variable，并且它没有在数据绑定类中显示它的setter和getter，那么Close++Open+from+Recent您的项目。|112414|2.更改类型后清理项目|112415|如果您更改了布局中某些<variable的类型，并且getter+setter类型没有更改，则清理项目setter|112416|最后一句话|112417|最后，如果您的绑定类仍然没有生成，那么我们就有了最强大的武器。-重启Android+Studio|112418|先尝试无效缓存，然后重新启动，这总是在restart.|112419|If之后生成我的绑定布局的变量它不工作然后&无效|112420|112421|这就是我为解决数据绑定错误所做的全部工作。如果你有任何进一步的问题，你可以在这里发表评论。|112422|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.android.com/studio/releases/|1|https://developer.android.com/studio/releases/gradle-plugin|2^0|0|0|0|F|B|0|3|L|0|P|K|1|0|0|0|9|O|0|0|0|0|0|4|C|J|4|Y|2|0|0|0|W|7|W|7|0|0|0|0|0|0|9|A|1B|5|K|H|1L|J|0|0|0|0|7|E|1B|1|7|E|0|0|0|A|0|0|1M|0|0|0|H|5|27|A|0|0|0|B|7|L|4|0|0|0|0|0|0|I|N|R|0|0|6|0|0|1K|2F|E|10|E|0|0|4|I|2|0|2|A|0|0|18|M|1V|I|0|0|M|9|1S|S|M|9|0|0|B|0|0|1L|B|9|0|0|5|0|0|1C|0|0|R|0|0|O|0|0|0|19|0^^$0|@$1|2|3|4|5|6|7|3R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|3S|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|3T|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|3U|8|@$H|3V|I|3W|J|K]]|9|@]|A|$]]|$1|L|3|M|5|6|7|3X|8|@]|9|@$H|3Y|I|3Z|1|40]|$H|41|I|42|1|43]]|A|$]]|$1|N|3|O|5|6|7|44|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|45|8|@]|9|@]|A|$]]|$1|Q|3|R|5|S|7|46|8|@$H|47|I|48|J|K]]|9|@]|A|$]]|$1|T|3|-4|5|6|7|49|8|@]|9|@]|A|$]]|$1|U|3|-4|5|6|7|4A|8|@]|9|@]|A|$]]|$1|V|3|W|5|6|7|4B|8|@]|9|@]|A|$]]|$1|X|3|Y|5|6|7|4C|8|@]|9|@]|A|$]]|$1|Z|3|10|5|6|7|4D|8|@$H|4E|I|4F|J|11]|$H|4G|I|4H|J|K]|$H|4I|I|4J|J|K]]|9|@]|A|$]]|$1|12|3|13|5|14|7|4K|8|@]|9|@]|A|$15|16]]|$1|17|3|18|5|6|7|4L|8|@]|9|@]|A|$]]|$1|19|3|1A|5|6|7|4M|8|@$H|4N|I|4O|J|K]|$H|4P|I|4Q|J|11]]|9|@]|A|$]]|$1|1B|3|1C|5|14|7|4R|8|@]|9|@]|A|$15|16]]|$1|1D|3|1E|5|6|7|4S|8|@]|9|@]|A|$]]|$1|1F|3|1G|5|6|7|4T|8|@]|9|@]|A|$]]|$1|1H|3|1I|5|6|7|4U|8|@]|9|@]|A|$]]|$1|1J|3|-4|5|6|7|4V|8|@]|9|@]|A|$]]|$1|1K|3|1L|5|S|7|4W|8|@$H|4X|I|4Y|J|K]|$H|4Z|I|50|J|K]|$H|51|I|52|J|11]|$H|53|I|54|J|11]]|9|@]|A|$]]|$1|1M|3|-4|5|6|7|55|8|@]|9|@]|A|$]]|$1|1N|3|-4|5|6|7|56|8|@]|9|@]|A|$]]|$1|1O|3|1P|5|6|7|57|8|@]|9|@]|A|$]]|$1|1Q|3|1R|5|6|7|58|8|@$H|59|I|5A|J|K]|$H|5B|I|5C|J|K]|$H|5D|I|5E|J|11]]|9|@]|A|$]]|$1|1S|3|1T|5|14|7|5F|8|@]|9|@]|A|$15|16]]|$1|1U|3|1V|5|6|7|5G|8|@$H|5H|I|5I|J|K]]|9|@]|A|$]]|$1|1W|3|1X|5|6|7|5J|8|@$H|5K|I|5L|J|K]]|9|@]|A|$]]|$1|1Y|3|-4|5|6|7|5M|8|@]|9|@]|A|$]]|$1|1Z|3|20|5|21|7|5N|8|@]|9|@]|A|$]]|$1|22|3|23|5|21|7|5O|8|@$H|5P|I|5Q|J|K]|$H|5R|I|5S|J|K]]|9|@]|A|$]]|$1|24|3|25|5|6|7|5T|8|@]|9|@]|A|$]]|$1|26|3|27|5|6|7|5U|8|@]|9|@]|A|$]]|$1|28|3|29|5|6|7|5V|8|@$H|5W|I|5X|J|11]|$H|5Y|I|5Z|J|11]]|9|@]|A|$]]|$1|2A|3|-4|5|6|7|60|8|@]|9|@]|A|$]]|$1|2B|3|2C|5|21|7|61|8|@]|9|@]|A|$]]|$1|2D|3|2E|5|21|7|62|8|@]|9|@]|A|$]]|$1|2F|3|2G|5|6|7|63|8|@]|9|@]|A|$]]|$1|2H|3|2I|5|6|7|64|8|@$H|65|I|66|J|K]|$H|67|I|68|J|K]]|9|@]|A|$]]|$1|2J|3|2K|5|6|7|69|8|@$H|6A|I|6B|J|K]]|9|@]|A|$]]|$1|2L|3|2M|5|6|7|6C|8|@$H|6D|I|6E|J|K]|$H|6F|I|6G|J|K]|$H|6H|I|6I|J|11]]|9|@]|A|$]]|$1|2N|3|2O|5|6|7|6J|8|@]|9|@]|A|$]]|$1|2P|3|2Q|5|6|7|6K|8|@]|9|@$H|6L|I|6M|1|6N]]|A|$]]|$1|2R|3|2S|5|6|7|6O|8|@$H|6P|I|6Q|J|11]]|9|@]|A|$]]|$1|2T|3|2U|5|14|7|6R|8|@]|9|@]|A|$15|16]]|$1|2V|3|2W|5|6|7|6S|8|@$H|6T|I|6U|J|11]|$H|6V|I|6W|J|11]]|9|@]|A|$]]|$1|2X|3|2Y|5|6|7|6X|8|@]|9|@]|A|$]]|$1|2Z|3|30|5|6|7|6Y|8|@$H|6Z|I|70|J|K]|$H|71|I|72|J|K]|$H|73|I|74|J|11]]|9|@]|A|$]]|$1|31|3|32|5|6|7|75|8|@$H|76|I|77|J|K]]|9|@]|A|$]]|$1|33|3|34|5|6|7|78|8|@$H|79|I|7A|J|K]|$H|7B|I|7C|J|11]]|9|@]|A|$]]|$1|35|3|36|5|6|7|7D|8|@$H|7E|I|7F|J|K]]|9|@]|A|$]]|$1|37|3|38|5|6|7|7G|8|@$H|7H|I|7I|J|K]]|9|@]|A|$]]|$1|39|3|3A|5|6|7|7J|8|@$H|7K|I|7L|J|K]]|9|@]|A|$]]|$1|3B|3|3C|5|21|7|7M|8|@$H|7N|I|7O|J|K]]|9|@]|A|$]]|$1|3D|3|-4|5|6|7|7P|8|@]|9|@]|A|$]]|$1|3E|3|3F|5|6|7|7Q|8|@$H|7R|I|7S|J|K]]|9|@]|A|$]]|$1|3G|3|-4|5|6|7|7T|8|@]|9|@]|A|$]]]|3H|$3I|$5|3J|3K|3L|A|$3M|3N]]|3O|$5|3J|3K|3L|A|$3M|3P]]|3Q|$5|3J|3K|3L|A|$3M|3N]]]]

I did not get any satisfying answers. So here are the tips which are summary of my data binding knowledge.
<h3>Tips For Solving DataBinding Issues</h3>
<h2>Update</h2>
To get more accurate errors and suggestions, I strongly recommend to update Android Studio and Gradle plugin version to the latest. Because I am not facing many issues after AS 3.2 version.
See <a href="https://developer.android.com/studio/releases/" rel="noreferrer">Latest Android Studio</a>, and <a href="https://developer.android.com/studio/releases/gradle-plugin" rel="noreferrer">Latest Gradle Plugin</a>.
<h2>Orignal Solution</h2>
<blockquote>
After reading this answer, you will not get stuck in data binding auto generation issues for both Classes and Data Variables.
</blockquote>
Check these points one by one. Any of these can make your work done. Point 3 to last are really important, so don't miss them.
<h3>1. Check if data-binding enabled</h3>
You should have data binding enabled in <code>build.gradle</code>. If not then add this and Sync.
<pre><code>android {
 ...
 buildFeatures {
 dataBinding true
 }
}
</code></pre>
<h3>2. Check layout is converted in binding layout</h3>
Now if you want data binding class to be generated then you should wrap <code>xml layout</code> with data binding (<code>&lt;layout</code> tag). Something like this.
<pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
&lt;layout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;&gt;

 &lt;android.support.constraint.ConstraintLayout
 android:layout_width=&quot;match_parent&quot;
 android:layout_height=&quot;match_parent&quot;&gt;

 &lt;/android.support.constraint.ConstraintLayout&gt;
&lt;/layout&gt;
</code></pre>
Along with this check whether the binding variable names are correct as in the view model class
<h3>3. Auto-generated Binding class name?</h3>
Your data binding class should be generated after creating binding layout.
<blockquote>
If your layout name is in snake case <code>activity_main.xml</code> then data binding class
will be generated in camel case like <code>ActivityMainBinding</code>.
</blockquote>
<h3>4. Can't See Import Suggestion?</h3>
Sometimes when you type <code>ActivityMai...</code>, then it does not show suggestion, in that case import manually.
<pre><code>import &lt;yourpackage&gt;databinding.ActivityMainBinding;
</code></pre>
<h3>5. Read Build Fail Logcat</h3>
Your binding class and new variables in layout will not be generated if your build fails. So first Make project by Ctrl + F9 (Build &gt; Make project).
<ul>
<li>If a build fails then see what is an error, usually we have errors in layout fields. Error logs will point out the error line number with the issue.</li>
<li>Binding may fail cause some stupid error, like syntax error or missing import. In that case, you will get logcat full of errors of binding classes. But you should read complete logcat to find appropriate issue.</li>
</ul>
<h3>6. Close and open project from recent</h3>
I always do this because it takes much less time than <code>Rebuild</code> / <code>Make</code> project.
<ul>
<li>Close project from File &gt; Close Project</li>
<li>Open again from recent</li>
</ul>
Note that I prefer Close and Open from Recent because it takes much less time than Rebuild / Restart IDE.
<h3>7. Rebuild Project</h3>
If still your class is not generated. (Some time when we paste layout file, then it happens). Then Rebuild Project from <code>Build&gt; Rebuild</code> (Not Build or Make project). It will generate your data binding class. (Rebuild does Magic for me.)
<h3>8. Have latest Android Studio</h3>
After updating AS to <a href="https://developer.android.com/studio/releases/" rel="noreferrer">Android Studio 3.2</a>, I felt many bugs fix in data binding auto generation. So you should also have the latest AS.
#Solution for <code>&lt;variables</code>
<pre><code>&lt;data&gt;
 &lt;variable
 name=&quot;item&quot;
 type=&quot;com.package.Model&quot;/&gt;
&lt;/data&gt;
</code></pre>
Usually, when we put a variable in layout, it creates a getter and setter of it. And we can use <code>binding.setItem(item);</code> and <code>binding.getItem();</code>, but if you can't see those methods then read the below information.
<h3>1. Close and open project from recent</h3>
If you have created a data variable - <code>&lt;variable</code> in your layout and it does not show up its setter and getter in data binding class, then Close and Open from Recent your project.
<h3>2. Clean project after changing the type</h3>
If you changed the type of some <code>&lt;variable</code> in your layout and getter setter type is not changing then Clean project (<code>Build&gt; Clean Project</code>)
<h3>Final words</h3>
Finally if still your binding class is not generated, then we have our most powerful weapon. - Restart Android Studio
<ul>
<li>First, try just restart, this always generates variables of my binding layout after restart.</li>
<li>If it does not work then Invalidate Cache &amp; Restart.</li>
</ul>
This is all that i do to solve my data binding errors. If you get any further issues, you can comment here.

blocks|key|110199|text|1.在app+gradle中添加以下内容|type|unstyled|depth|inlineStyleRanges|entityRanges|data|110200|+dataBinding+{
++++++++enabled+=+true
++++}|code-block|syntax|javascript|110201|2.在xml布局中编写以下代码|110202|<layout
++++xmlns:android="http://schemas.android.com/apk/res/android">
++<data></data>
</layout>if+you+don't+get+data+binding+class+just+rename+the+layout+file+name+and+you+will+get+data+binding+class.|110203|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

1.Add Below in app gradle

<pre><code> dataBinding {
 enabled = true
 }
</code></pre>

2.In xml layout write below code

<pre><code>&lt;layout
 xmlns:android="http://schemas.android.com/apk/res/android"&gt;
 &lt;data&gt;&lt;/data&gt;
&lt;/layout&gt;if you don't get data binding class just rename the layout file name and you will get data binding class.
</code></pre>

blocks|key|110205|text|我不知道它是否会对你起作用。只需重命名布局XML文件名即可。例如，假设您的布局名称为activity_main.xml，只需更改将其重命名为类似于main.xml的名称，然后再次将其重命名为activity_main.xml.然后，您可以在ActivityMainBinding.上看到导入选项|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|110206|希望它能为你工作。|110207|entityMap^0|16|H|21|8|2N|H|3C|J|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|I|$]]

I do not know it will work for you or not. Just rename the layout XML file name. Like suppose your layout name is activity_main.xml just change rename it to anything like main.xml and again rename it to activity_main.xml. Then you can able to see the import option on ActivityMainBinding.

Hope it works for you.

blocks|key|2656069|text|dataBinding+{
++++++++enabled+=+true
++++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2656070|要启用新的数据绑定编译器，请将以下选项添加到gradle.properties文件：|unstyled|2656071|android.databinding.enableV2=true|2656072|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>dataBinding {
 enabled = true
 }
</code></pre>

To enable the new data binding compiler, add the following option to your gradle.properties file:

<pre><code>android.databinding.enableV2=true
</code></pre>

blocks|key|2656175|text|当您使用Android多模块应用程序时，请检查绑定类路径。也许你应该使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2656176|import+com.yourcompany.app.android.modulename.databinding.FragmentABCtBinding实例：|offset|length|style|CODE|2656177|import+com.yourcompany.app.android.databinding.FragmentABCtBinding|2656178|entityMap^0|0|0|25|0|0|1U|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@$D|Q|E|R|F|G]]|9|@]|A|$]]|$1|J|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|K|$]]

When you work with a multimodule Android application check your binding class path. Maybe you should use:

<code>import com.yourcompany.app.android.modulename.databinding.FragmentABCtBinding</code>
insted of:

<code>import com.yourcompany.app.android.databinding.FragmentABCtBinding</code>

blocks|key|112898|text|如果你做了基础工作，为了在你项目中启用数据绑定，比如在gradle中使用xml和在xml中使用layout标签，当你修改代码而没有为这些生成新的数据绑定类时，你可以使用一种快速的方法在gradle->other->databindinggenbaseclassesDebug中生成只有数据绑定的类，它比构建整个项目更快。它只生成数据绑定类。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|112899|📷|atomic|112900|​|112901|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/996c5526ff33c7653bc6d8c1a2f65519.png|imageAlt^0|1B|3F|0|0|1|0|1|0|0|0|1|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|I|3|J|5|6|7|12|8|@$9|13|A|14|B|C]]|D|@]|E|$]]|$1|K|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R|S|-4]]]]

if you do base job, for enable databainding in your project, like use enable in gradle and use layout tag in xml, when you change xml code and did not generat new databinding class for those xml you can use a fast way for generation only data binding class in gradle->other->databindinggenbaseclassesDebug it fast more than bulid whole project. its generate only databinding class. 
<a href="https://i.stack.imgur.com/bEmx6.png" rel="noreferrer"><img src="https://i.stack.imgur.com/bEmx6.png" alt="enter image description here"></a>

blocks|key|112912|text|多亏了this+answer+here+--看起来“布局名称空间”要么需要清空，要么需要一个新的唯一名称。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|112913|以下是对我有效的选项：|112914|112915|为布局创建一个新名称，以确保可以生成该布局。这解决了我的问题，我有一个布局是首先创建的，没有数据绑定-让我们称它为fragment_abc.xml。当我尝试向它添加数据绑定时，它无法识别-即使在多次清除缓存和重启调用之后也是如此。但是，我一复制布局fragment_abc2.xml，就立即得到了生成的数据绑定.java/.class对象。|ordered-list-item|style|BOLD|CODE|112916|在看到上面的工作后，我尝试只从模块中删除/build文件夹，并重新构建项目-这项工作是为了获得原始布局的数据绑定。|112917|112918|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/44707001/2162226^0|3|G|0|0|0|0|12|C|1L|G|3G|H|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@$A|Y|B|Z|1|10]]|C|$]]|$1|D|3|E|5|6|7|11|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|12|8|@]|9|@]|C|$]]|$1|G|3|H|5|I|7|13|8|@$A|14|B|15|J|K]|$A|16|B|17|J|L]|$A|18|B|19|J|L]]|9|@]|C|$]]|$1|M|3|N|5|I|7|1A|8|@]|9|@]|C|$]]|$1|O|3|-4|5|6|7|1B|8|@]|9|@]|C|$]]|$1|P|3|-4|5|6|7|1C|8|@]|9|@]|C|$]]]|Q|$R|$5|S|T|U|C|$V|W]]]]

Thanks to <a href="https://stackoverflow.com/a/44707001/2162226">this answer here</a> - it looks like the "layout namespace" needs to either be cleared out, or you need a new unique name.

Here are the options that worked for me:

<ol>
<li>Create a fresh name for the layout to make sure it can be generated. This solved my issue, where I had a layout that was first created, without data binding - let's call it <code>fragment_abc.xml</code>. When I tried to add data binding to it, it was not recognized - even after multiple clear cache &amp; restart calls. However, soon as I made a copy of the layout <code>fragment_abc2.xml</code>, immediately I got the generated data-binding .java/.class object.</li>
<li>After seeing the above work, I tried to just remove the /build folder from the module, and rebuilt the project - this worked to get data binding for the original layout.</li>
</ol>

blocks|key|2867205|text|我遇到了一个类似的问题，我在gradle文件中包装了布局并启用了数据绑定。Main+activity仍然无法智能感知或查看我的类。对我来说，修复它的方法是添加绑定变量并导入绑定。从那里我只是构建了解决方案，然后它似乎知道了类是什么。从那里，我能够导入生成的驼峰案例类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2867206|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I had a similar issue where I had the layout wrapped and my data binding enabled in the gradle file. Main activity still couldn't intellisense or see my classes. What fixed it for me was adding the binding variable and importing the binding anyway. From there I just built the solution and then it seemed to know what the class was. From there I was able to import my camel case classes that were generated.

blocks|key|2867336|text|我得到了问题，问题出在布局中，使用的字段不是字符串，而是日期。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2867337|看起来所有的字段都必须是文本才能工作，至少对于TexView组件是这样。|2867338|如果使用./gradlew+build+--stacktrace命令进行构建|2867339|这样可以更好地显示错误。|2867340|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

I got the issue and the problem was in the layout the field used was not a String, it was a Date. 

Looks that all field got to be text to work, at least with the TexView component.

If you build with the command
./gradlew build --stacktrace

This show better the errors.

blocks|key|2867346|text|在我的例子中，我认为生成的类必须与我常用的类一起出现在src文件夹中。此外，我认为生成的类的名称应该略有不同。这都是我的错。生成的类可以在build文件夹、build+->+generated+->+...路径中找到。如果您的活动中没有导入生成的类，请添加导入|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2867347|import+com.yourcompany.app.databinding.ActivityMainBinding;"|code-block|syntax|javascript|2867348|entityMap^0|R|3|1X|5|26|P|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|U|8|@]|D|@]|E|$]]]|L|$]]

In my case, I thought that generated class had to appear with my usual classes in <code>src</code> folder. In addition, I thought that the name of the generated class should be slightly different. It all was my mistake. The generated class can be found in <code>build</code> folder, <code>build -&gt; generated -&gt; ...</code> path. If there is no import of the generated class in your activity, add the import 

<pre><code>import com.yourcompany.app.databinding.ActivityMainBinding;"
</code></pre>

blocks|key|112634|text|删除布局和撤消，并确保生成的绑定类在此之后正确导入。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|112635|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Delete layouts and undo, and make sure the generated binding classes are imported correctly after that.

blocks|key|2656423|text|如果最近有人将现有项目迁移到androidx中，那么您需要从|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|2656424|import+com.yourpackagename.BR;|code-block|syntax|javascript|2656425|至|2656426|import+androidx.databinding.library.baseAdapters.BR;|2656427|谷歌两天后终于得到了解决方案，其中一个对我来说是有效的。|2656428|entityMap^0|E|8|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|Y|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

If Recently any one migrated existing project into androidx then you need to replace your import from

<pre><code>import com.yourpackagename.BR;
</code></pre>

to

<pre><code>import androidx.databinding.library.baseAdapters.BR;
</code></pre>

After Google 2 days finally got solution, which one work for me.

blocks|key|113046|text|以防您在DataBindingUtil.setContentView中得到以下错误|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113047|未解析的|113048|引用:+activity_main|blockquote|113049|113050|113051|您所需要做的就是删除以下import语句|113052|113053|导入android.R。R|113054|113055|113056|我在另一个论坛上找到了解决方案。Source|offset|length|113057|entityMap|0|LINK|mutability|MUTABLE|url|https://www.oipapio.com/question-12143853^0|0|0|0|0|0|0|0|0|0|0|G|6|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|12|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|13|8|@]|9|@]|A|$]]|$1|G|3|-4|5|6|7|14|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|15|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|16|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|17|8|@]|9|@]|A|$]]|$1|L|3|M|5|F|7|18|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|19|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1B|8|@]|9|@$R|1C|S|1D|1|1E]]|A|$]]|$1|T|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|U|$V|$5|W|X|Y|A|$Z|10]]]]

In case you get the following error in DataBindingUtil.setContentView 

<blockquote>
 Unresolved reference: activity_main
</blockquote>

all you need to do is remove the following import statement

<blockquote>
 import android.R
</blockquote>

I found the solution on another forum. <a href="https://www.oipapio.com/question-12143853" rel="nofollow noreferrer">Source</a>

blocks|key|110390|text|在某些情况下，您在生成的目录下看不到文件，您可能绑定了一个未在viewmodel中声明的属性。如果您在xml中这样做，它实际上不会给您一个lint错误。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|110391|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

There are cases when you won't see a file under generated directory, you might be binding a property that is not declared in viewmodel. It doesn't essentially give you a lint error if you do so in xml.

blocks|key|2656534|text|如果要实现可序列化+->，则必须实现可序列化|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|2656535|否则，您将得到此错误。希望它能在未来帮助某些人|2656536|在我的例子中，我使用了Parcel库。我错过了在我的子类中注释@Parcel|2656537|entityMap^0|5|4|I|4|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|R|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|K|$]]

If you are implement the Serializable -> you must implement the Serializable

else you will get this error. Hope it will help someone in future 

In my case I use the Parcel library. I missed to annotate @Parcel in my sub class

blocks|key|113075|text|除了上述步骤外，您还可以检查变量类型。确保它是TextView的字符串或与BindingAdapter中定义的相同。例如：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|113076|data+class+MyDataObject(val+name:+String,+val+age:+Int)|code-block|syntax|javascript|113077|在XML中：|113078|android:text="@{dataobject.age}"|113079|这将导致上述错误。要修复此问题，您可以将年龄变量设置为String类型，也可以在XML中导入String并使用String.valueOf(age)，如下所示：|113080|<data>
++++<import+type="String"+/>
...
</data>|113081|在你的TextView中：|113082|android:text="@{String.valueOf(dataobject.age)}"|113083|entityMap^0|11|E|0|0|0|0|1J|J|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|12|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|14|8|@$9|15|A|16|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|H|7|17|8|@]|D|@]|E|$I|J]]|$1|S|3|T|5|6|7|18|8|@]|D|@]|E|$]]|$1|U|3|V|5|H|7|19|8|@]|D|@]|E|$I|J]]|$1|W|3|-4|5|6|7|1A|8|@]|D|@]|E|$]]]|X|$]]

In addition to the above steps, you can also check the variable type. Make sure it's String for TextView or the same as defined in the <code>BindingAdapter</code>.
For example:

<pre><code>data class MyDataObject(val name: String, val age: Int)
</code></pre>

and in XML:

<pre><code>android:text="@{dataobject.age}"
</code></pre>

This will cause the above error. To fix you can either make the age variable of type String or you can import String in your XML and use <code>String.valueOf(age)</code> as following:

<pre><code>&lt;data&gt;
 &lt;import type="String" /&gt;
...
&lt;/data&gt;
</code></pre>

And in your TextView:

<pre><code>android:text="@{String.valueOf(dataobject.age)}"
</code></pre>

blocks|key|113085|text|如果您的XML文件有问题，将不会生成数据绑定类。一种快速的解决方法是遍历XML文件并检查语法错误(通常以红色突出显示)。错误可能以不存在或错误的引用、排版错误等形式出现。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|113086|本质上，只要确保XML代码中没有带红色下划线的行即可。当你完成后，重新生成你的数据绑定类。|113087|entityMap^0|N|1Q|0|0|19|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

If there is an issue with your XML file, the Databinding class would not be generated. A quick fix would be to run through the XML file and check for syntax errors (which are usually highlighted in red). The errors might come in the form of non-existing or wrong references, typographical errors, etc.

In essence, just make sure there is no red-underlined line in your XML code. When you are done, rebuild and your Databinding class would have been generated.

blocks|key|110465|text|我的解决方案是在类名中使用后缀FragmentBinding。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|110466|110467|为每个布局文件生成一个绑定类。默认情况下，类的名称基于布局文件的名称，将其转换为Pascal大小写并添加绑定后缀。上面的布局文件名是activity_main.xml，因此对应的生成类是ActivityMainBinding。该类保存从布局属性(例如，用户变量)到布局视图的所有绑定，并知道如何为绑定表达式赋值。|blockquote|110468|110469|110470|活动或片段类的名称的命名可以根据前缀而有所不同。因为后缀总是有约束力的。|110471|在遵循Khemraj和无效缓存/重新启动的响应之后，您应该重写ActivityBinding或FragmentBinding，以获得已经生成的类的集成开发环境建议，并且不对导入进行硬编码。|offset|length|style|BOLD|110472|在我的例子中，我试图向后导入类名为FragmentCompetitionsBinding而不是CompetitionsFragmentBinding。|CODE|110473|总帐|110474|Source|110475|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/51579759/5279996|1|https://developer.android.com/topic/libraries/data-binding/generated-binding.html#custom_binding_class_names^0|0|0|0|0|0|0|Q|10|3|7|0|0|H|R|1B|R|0|0|0|6|1|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|17|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|18|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|19|8|@]|9|@]|A|$]]|$1|G|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|1B|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|1C|8|@$L|1D|M|1E|N|O]]|9|@$L|1F|M|1G|1|1H]]|A|$]]|$1|P|3|Q|5|6|7|1I|8|@$L|1J|M|1K|N|R]|$L|1L|M|1M|N|R]]|9|@]|A|$]]|$1|S|3|T|5|6|7|1N|8|@]|9|@]|A|$]]|$1|U|3|V|5|6|7|1O|8|@]|9|@$L|1P|M|1Q|1|1R]]|A|$]]|$1|W|3|-4|5|6|7|1S|8|@]|9|@]|A|$]]]|X|$Y|$5|Z|10|11|A|$12|13]]|14|$5|Z|10|11|A|$12|15]]]]

<h2>My solution was to take as a suffix FragmentBinding in the class name.</h2>

<blockquote>
 A binding class is generated for each layout file. By default, the name of the class is based on the name of the layout file, converting it to Pascal case and adding the Binding suffix to it. The above layout filename is activity_main.xml so the corresponding generated class is ActivityMainBinding. This class holds all the bindings from the layout properties (for example, the user variable) to the layout's views and knows how to assign values for the binding expressions.
</blockquote>

The nomenclature of the name of the activity or fragment class may vary in terms of prefixes. Because the suffix is always Binding.

After following the response of <a href="https://stackoverflow.com/a/51579759/5279996">Khemraj</a> and Invalidate Caches / Restart, you should rewrite ActivityBinding or FragmentBinding to get the IDE suggestions of the classes that were already generated and DO NOT hardcode the import.

In my case I was trying to import the name of the class backwards be <code>FragmentCompetitionsBinding</code> instead of <code>CompetitionsFragmentBinding</code>.

GL

<a href="https://developer.android.com/topic/libraries/data-binding/generated-binding.html#custom_binding_class_names" rel="nofollow noreferrer">Source</a>

blocks|key|113169|text|在我的例子中，没有生成数据绑定类，因为我已经删除了mipmap+Android+Resource+Directory。我重新创建了res/mipmap/目录，并恢复了数据绑定类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113170|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In my case, data binding classes were not generated because I had deleted the mipmap Android Resource Directory. I recreated the res/mipmap/ directory and the data binding classes were reinstated.

blocks|key|2656665|text|我遇到了一个类似的问题，DataBinding无法生成BindingImpl类。在我的例子中，数据类中的一个方法出现了名称使用错误的问题:模型包含一个方法onSignInCliked()，而在布局中我使用了onSigninCliked().请注意SignIn+vs+Signin。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|2656666|错误消息是不够的，只有当我使用带有stack-trace选项的构建脚本时，我才发现了问题。|2656667|entityMap^0|R|B|25|G|2V|G|3F|6|3P|6|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|I|$]]

I encountered a similar issue where DataBinding failed to generate the BindingImpl class.
In my case was an issue from a method in the data class where the name was used wrong:
The model contained a method onSignInCliked() and in the layout I used onSigninCliked(). Notice the SignIn vs Signin.

The error message wasn't enough and I discovered the issue only when I used the build script with the stack-trace option.

blocks|key|113175|text|确保数据绑定已启用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113176|​|113177|android+{
...
+++dataBinding+{
++++++++enabled+=+true
++++}
...
}|code-block|syntax|javascript|113178|113179|113180|📷|atomic|offset|length|113181|dan点击按钮(与Gradle同步项目)|113182|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/d28df6d6b2a6d5c1e26dc57a4981778d.png|imageAlt^0|0|0|0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|13|8|@]|9|@]|A|$]]|$1|J|3|C|5|6|7|14|8|@]|9|@]|A|$]]|$1|K|3|L|5|M|7|15|8|@]|9|@$N|16|O|17|1|18]]|A|$]]|$1|P|3|Q|5|6|7|19|8|@]|9|@]|A|$]]|$1|R|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]]|S|$T|$5|U|V|W|A|$X|Y|Z|-4]]]]

Make sure data binding enabled

<div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-html lang-html prettyprint-override"><code>android {
...
 dataBinding {
 enabled = true
 }
...
}</code></pre>
</div>
</div>


<a href="https://i.stack.imgur.com/HP03J.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HP03J.png" alt="Sync project with gradle"></a>
dan click the button (Sync project with Gradle)

blocks|key|2656790|text|如果answer对你不起作用，那么我的建议是简单但有效的。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2656791|我们的想法是确定哪个组件是产生问题的组件。要做到这一点，在custom_fragment.xml的所有行上添加注释，并在+CustomFragment.kt中使用，并保留如下所示的最小化内容。|style|CODE|BOLD|2656792|<layout+xmlns:android="http://schemas.android.com/apk/res/android"
++++xmlns:app="http://schemas.android.com/apk/res-auto"
++++xmlns:tools="http://schemas.android.com/tools">

++++<androidx.constraintlayout.widget.ConstraintLayout
++++++++android:id="@%2Bid/test"
++++++++android:layout_width="match_parent"
++++++++android:layout_height="match_parent"/>

</layout>|code-block|syntax|javascript|2656793|然后运行应用程序并添加组件到组件，同时Apply+Code+Changes+(Ctrl%2BAlt%2BF10)到应用程序的执行，直到应用程序崩溃，也就是您发现故障的时候。|2656794|数据绑定日志有时并不那么具有描述性，这是一种查找故障组件的通用策略。|2656795|总帐|2656796|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/51579759/5279996^0|2|6|0|0|T|J|1P|H|1P|K|0|0|J|I|0|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@]|9|@$A|12|B|13|1|14]]|C|$]]|$1|D|3|E|5|6|7|15|8|@$A|16|B|17|F|G]|$A|18|B|19|F|G]|$A|1A|B|1B|F|H]]|9|@]|C|$]]|$1|I|3|J|5|K|7|1C|8|@]|9|@]|C|$L|M]]|$1|N|3|O|5|6|7|1D|8|@$A|1E|B|1F|F|G]]|9|@]|C|$]]|$1|P|3|Q|5|6|7|1G|8|@]|9|@]|C|$]]|$1|R|3|S|5|6|7|1H|8|@]|9|@]|C|$]]|$1|T|3|-4|5|6|7|1I|8|@]|9|@]|C|$]]]|U|$V|$5|W|X|Y|C|$Z|10]]]]

If <a href="https://stackoverflow.com/a/51579759/5279996">answer</a> did not work for you, then my recommendation is simple but effective.
The idea is to determine which is the component that is generating the problem. To do this, comment on all the lines of your <code>custom_fragment.xml</code> and its uses in the <code>CustomFragment.kt</code> and leave something minimalist like the following.
<pre><code>&lt;layout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
 xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
 xmlns:tools=&quot;http://schemas.android.com/tools&quot;&gt;

 &lt;androidx.constraintlayout.widget.ConstraintLayout
 android:id=&quot;@+id/test&quot;
 android:layout_width=&quot;match_parent&quot;
 android:layout_height=&quot;match_parent&quot;/&gt;

&lt;/layout&gt;
</code></pre>
<h2>Then run the app and add component to component while you <code>Apply Code Changes</code> (Ctrl+Alt+F10) to the execution of the app until the app crashes, that is when you found the fault.</h2>
Data binding logs are sometimes not so descriptive and this is a generic strategy to find the faulty component.
GL

blocks|key|2656813|text|我生成了所有的类，但Android+Studio看不到它们，并将它们标记为无效导入。运行gradle+sync解决了这个问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2656814|​|2656815|📷|atomic|offset|length|2656816|2656817|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/c77dedb60a778303e6016235ec6fb1d2.png|imageAlt^0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@$G|V|H|W|1|X]]|A|$]]|$1|I|3|C|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q|R|-4]]]]

I had all classes generated, but Android Studio did not see them and marked them as invalid imports. Running gradle sync solved the issue.
<a href="https://i.stack.imgur.com/esgrb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/esgrb.png" alt="Android Studio - gradle sync" /></a>

blocks|key|2867914|text|我也有同样的问题。我在重构的时候犯了一个错误。autogen绑定类的名称来自xml布局文件。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2867915|fragment_name.xml+->+FragmentNameBinding|2867916|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I had the same problem. I made a mistake while I refactored.
The autogen binding class has its name from the xml layout file.
fragment_name.xml -&gt; FragmentNameBinding

blocks|key|2656860|text|检查接受答案中的所有原因后，请确保与file.xml中的命名完全匹配。在我的例子中，我的布局名称中有一个小小的打字错误。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2656861|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

After you check all the reasons in the accepted answer, make sure to match to the exact naming in the file.xml. In my case I had a tiny typo in my layout name.

I am using Data Binding in my project, when using <code>&lt;layout&gt;</code> and <code>&lt;data&gt;</code> in my xml binding class is not generated.

For example i have activity_main.xml 

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;layout xmlns:android="http://schemas.android.com/apk/res/android"&gt;
 &lt;data&gt; &lt;/data&gt;
 &lt;RelativeLayout
 android:layout_width="match_parent"
 android:layout_height="match_parent"&gt;
 &lt;/RelativeLayout&gt;
&lt;/layout&gt;
</code></pre>

Now if i am writing <code>ActivityMainBinding</code> in my activity/fragment it shows error that class is not available. But after including <code>&lt;variable&gt;</code> in my xml file, it is able to generate <code>ActivityMainBinding</code> class.

Android Studio : 2.1.3 
Classpath : com.android.tools.build:gradle:2.1.3 
minSdkVersion 16 
targetSdkVersion 24 
buildToolsVersion 24.0.0

Data Binding class not generated

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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当在我的xml Binding类中使用<layout>和<data>时，我在我的项目中使用数据绑定。例如，我有activity_main.xml<?xml version="1.0" encoding="utf-8"?><layout xmlns:android="http://schemas.android.com/...

问未生成数据绑定类
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