blocks|key|4485216|text|您是否为数据绑定更新了布局文件？它们只为具有数据绑定的布局生成。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4485217|它必须从一个layout标签开始，这个标签有2个子标签(data+&你的根视图)。|offset|length|style|CODE|4485218|如下所示：|4485219|<?xml+version="1.0"+encoding="utf-8"?>
<layout+xmlns:android="http://schemas.android.com/apk/res/android">
+++<data>
+++++++<variable+name="user"+type="com.example.User"/>
+++</data>
+++<LinearLayout+...
+++</LinearLayout>
</layout>|code-block|syntax|javascript|4485220|当您的布局具有此表单时，AndroidStudio应自动完成类。另外，默认情况下，它是在<your.app.package>.databinding包中生成的。|4485221|entityMap^0|0|6|6|0|0|0|18|U|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@$D|U|E|V|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|W|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|X|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|Y|8|@$D|Z|E|10|F|G]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|R|$]]

Did you update your layout file for data binding? They are generated only for layouts which have data binding.

It has to start with a <code>layout</code> tag which has 2 child tags (data &amp; your root view).

Something like this:

<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;variable name="user" type="com.example.User"/&gt;
 &lt;/data&gt;
 &lt;LinearLayout ...
 &lt;/LinearLayout&gt;
&lt;/layout&gt;
</code></pre>

When your layout has this form, AndroidStudio should auto complete the class. Also, by default, it is generated in <code>&lt;your.app.package&gt;.databinding</code> package.

blocks|key|4486300|text|当它没有生成绑定类时，我重新启动Android+studio。然后，将生成绑定类。是不是android+studio的缓存造成的？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4486301|顺便说一句，如果你正在使用android-apt，请检查它。因为它将导致不生成绑定类。|offset|length|style|CODE|4486302|entityMap^0|0|D|B|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

When it's not generating the binding class, I restart Android studio. Then the binding class will be generated. Isn't it caused by cache of android studio?

BTW, if you are using <code>android-apt</code>, please check it. Because it will cause binding class not to be generate.

blocks|key|4485285|text|在我的例子中，重新启动Android+Studio是可行的。它是android-apt中的bug|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4485286|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 Restarting Android Studio does work. It is bug in android-apt

blocks|key|4486393|text|android-studio中的一个奇怪的"bug“导致生成的BR.java文件不使用@Bindable字段，并且在res/layout目录不存在的情况下仍然只有_all属性。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4486394|当我想创建一个“无活动”应用程序来拥有一个包含我的不同可绑定数据的库时，它发生在我身上。|4486395|entityMap^0|17|9|29|4|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

A weird "bug" in android-studio causes the generated BR.java file not to use the <code>@Bindable</code> fields and still only have the <code>_all</code> property if a res/layout directory doesn't exist.

It happened to me when I wanted to create a "No Activity" App to have a library that contained my different bindable data.

blocks|key|4485433|text|只是简单的重启对我来说不起作用。我必须使用Invalidate+Caches+and+Restart才能看到绑定类。对于那些不知道的人，它在File菜单下。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4485434|entityMap^0|L|T|1Y|4|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|$]]

Just a simple restart didn't work for me. I had to <code>Invalidate Caches and Restart</code> then I could see the binding classes. It's under the <code>File</code> menu for those who don't know.

blocks|key|4485478|text|在我的例子中，我只是将布局xml封装在<layout></layout>标记中，就是这样，没有添加数据标记，我就成功地生成了数据绑定。希望这能有所帮助。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4485479|<data>
+++++++<variable+name="user"+type="com.example.User"/>
</data>|code-block|syntax|javascript|4485480|entityMap^0|J|H|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

In my case i just enclosed my layout xml in <code>&lt;layout&gt;&lt;/layout&gt;</code> tags and that's it, without adding the data tag, i was successful to generate Data Bindings. Hope this helps.

<pre><code>&lt;data&gt;
 &lt;variable name="user" type="com.example.User"/&gt;
&lt;/data&gt;
</code></pre>

blocks|key|4485517|text|<data+class="MainActivityBinding">
++++<variable
++++++++name="user"
++++++++type="com.example.administrator.my_mvvm.User"+/>
</data>|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4485518|//记住需要生成->重建项目|unstyled|4485519|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>&lt;data class="MainActivityBinding"&gt;
 &lt;variable
 name="user"
 type="com.example.administrator.my_mvvm.User" /&gt;
&lt;/data&gt;
</code></pre>

//Remember need 
Build-> Rebuild Project

blocks|key|4486560|text|检查您的对象的字段访问级别，当我将其设置为public时，它在这里工作|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4486561|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|$]]

check the fields access level of your object, when i turned public it worked here

blocks|key|4485622|text|我遇到了一个类似的问题，这里还没有提到。在我的例子中，我错误地添加了<Layout>作为标签，而不是<layout>。<Layout>显然是一个有效的标签，因为Android+Studio没有抱怨(除了需要layout_width和layout_height，这对于<layout>来说不是必需的)。大小写的差异将在类似的行为中体现出来，即使<Layout>是一个有效的标记并且build.gradle文件被正确地定义为支持数据绑定，您也不能在MainActivity类中导入数据绑定类(在我的例子中是导入com.example.android.aboutme.databinding.ActivityMainBinding+)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4485623|在我的例子中，我还不需要定义<data>标记就可以有效地导入ActivityMainBinding并在其中被引用：|4485624|private+lateinit+var+binding:+ActivityMainBinding|4485625|我正在使用this+codelab时遇到了这样的行为：https://developer.android.com/codelabs/kotlin-android-training-data-binding-basics/index.html|4485626|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.android.com/codelabs/kotlin-android-training-data-binding-basics/index.html^0|Y|8|1E|8|1N|8|3P|8|4R|8|0|E|6|0|0|1D|0|R|2L|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|14|8|@$9|15|A|16|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|17|8|@$9|18|A|19|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|1A|8|@]|D|@$9|1B|A|1C|1|1D]]|E|$]]|$1|L|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]]|M|$N|$5|O|P|Q|E|$R|S]]]]

I ran into a similar issue that hasn't been mentioned here yet. In my case, I incorrectly added <code>&lt;Layout&gt;</code> as the tag versus <code>&lt;layout&gt;</code>. <code>&lt;Layout&gt;</code> is apparently a valid tag because Android Studio didn't complain (other than requiring layout_width and layout_height which aren't required for <code>&lt;layout&gt;</code>). The capitalization difference will manifest in similar behavior where you cannot import the databinding class (import com.example.android.aboutme.databinding.ActivityMainBinding in my case) in the MainActivity class even though <code>&lt;Layout&gt;</code> is a valid tag and the build.gradle file is defined properly to support data binding.
In my case, I did not need the <code>&lt;data&gt;</code> tags defined yet in order for ActivityMainBinding to validly import and be referenced in:
<code>private lateinit var binding: ActivityMainBinding</code>
I was working through the this codelab when I ran into this behavior: <a href="https://developer.android.com/codelabs/kotlin-android-training-data-binding-basics/index.html" rel="nofollow noreferrer">https://developer.android.com/codelabs/kotlin-android-training-data-binding-basics/index.html</a>

blocks|key|4486633|text|嗨，也许你也可以试试这个，把这个包含在build.gradle(:app)中|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4486634|android代码块内部|4486635|buildFeatures+{+viewBinding+true+}|4486636|对我很管用，也许对你也一样|4486637|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|$]]

Hi maybe you can try this as well include this in build.gradle(:app)
inside the android block
buildFeatures {
viewBinding true
}
worked for me, maybe it could for you as well

blocks|key|4485694|text|activity_main.xml文件需要以布局标签开头，如下所示。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4485695|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|$]]

activity_main.xml file needs to start with layout tag as shown below.

<a href="https://developer.android.com/tools/data-binding/guide.html" rel="noreferrer">DataBinding Guide</a> States

<pre><code> By default, a Binding class will be generated based on the name of the layout 
file, converting it to Pascal case and suffixing “Binding” to it. 
The above layout file was activity_main.xml so the generate class was ActivityMainBinding.
</code></pre>

When will the Binding class , here say ActivityMainBinding, will be generated. I have compile time error. "cannot resolve ActivityMainBinding".

<pre><code>ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.main_activity);
</code></pre>

Any help is appreciated. Thanks

Android - DataBinding - How and when the Binding classes will be 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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状态  By default, a Binding class will be generated based on the name of the layout file, converting it to Pascal case and suffixing “Binding” to it. The above la...

问Android - DataBinding -如何以及何时生成绑定类？
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