blocks|key|410676|text|你在文章中提到的两个实现都提供了CursorLoader+的所有好处，除了当底层内容发生变化时接收通知的能力。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|BOLD|entityRanges|data|410677|我最近研究了很多，我可以自信地告诉你，Android+API目前没有提供一种只使用原始SQLiteDatabase来实现这一点的方法(它只提供了ContentResolver#notifyChange()和Cursor#setNotificationUri()方法，这两个方法用于通知所有在某个通知Uri下注册的Cursor)。|410678|也就是说，你现在的选择是：|410679|410680|自己实现了一个观察器，它能够在内容更改时接收来自SQLiteDatabase的通知，并且能够以某种方式将这些通知转发给应用程序中的所有现有Loader。我写了一个相当广泛的关于如何实现Loader的，如果你想接受这个挑战，它可能会派上用场。或者...|ordered-list-item|410681|使用Mark+Murphy的LoaderEx库，并且只使用他的库提供的AsyncTask操作进行数据库修改。请注意，他的任务刷新Loader的原因是，它们在执行插入/更新/删除操作后立即调用Loader上的onContentChanged，有效地告诉Loader内容已更改，应该刷新其数据。|410682|只需使用具有CursorLoader的ContentProvider，您可以使用ContentResolver#notifyChange()方法通知<代码>D27发生了内容更改。<代码>H228<代码>G229|410683|410684|我正在尝试找出一个更好的解决方案，如果我找到/实现了一个解决方案，我会在未来向您报告，但目前这些解决方案已经足够了。|410685|entityMap^0|G|C|T|8|0|17|E|20|U|2V|R|45|3|4C|6|0|0|0|O|E|1X|6|2K|6|0|E|8|Z|9|1S|6|2N|6|2V|G|3H|6|0|6|C|J|F|14|U|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|D]]|E|@]|F|$]]|$1|G|3|H|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]]|E|@]|F|$]]|$1|I|3|J|5|6|7|1D|8|@]|E|@]|F|$]]|$1|K|3|-4|5|6|7|1E|8|@]|E|@]|F|$]]|$1|L|3|M|5|N|7|1F|8|@$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]]|E|@]|F|$]]|$1|O|3|P|5|N|7|1M|8|@$9|1N|A|1O|B|C]|$9|1P|A|1Q|B|C]|$9|1R|A|1S|B|C]|$9|1T|A|1U|B|C]|$9|1V|A|1W|B|C]|$9|1X|A|1Y|B|C]]|E|@]|F|$]]|$1|Q|3|R|5|N|7|1Z|8|@$9|20|A|21|B|C]|$9|22|A|23|B|C]|$9|24|A|25|B|C]]|E|@]|F|$]]|$1|S|3|-4|5|6|7|26|8|@]|E|@]|F|$]]|$1|T|3|U|5|6|7|27|8|@]|E|@]|F|$]]|$1|V|3|-4|5|6|7|28|8|@]|E|@]|F|$]]]|W|$]]

The two implementations you mention in your post both offer all of the benefits of the <code>CursorLoader</code> except the ability to receive notifications when the underlying content changes. 

I've been looking into this a lot recently and I can confidently tell you that the Android API currently does not provide a means of doing this with only a raw <code>SQLiteDatabase</code> (it only provides the <code>ContentResolver#notifyChange()</code> and <code>Cursor#setNotificationUri()</code> methods, which are used to notify all <code>Cursor</code>s registered under a certain notification <code>Uri</code>).

That said, your options right now are to:

<ol>
<li>Implement an observer yourself that is capable of receiving notifications from the <code>SQLiteDatabase</code> when the content changes, and is somehow able to relay these notifications to all existing <code>Loader</code>s in your application. I wrote a pretty extensive <a href="http://www.androiddesignpatterns.com/2012/08/implementing-loaders.html" rel="noreferrer">blog post</a> on how to implement <code>Loader</code>s that might come in handy if you wish to take on this challenge. Or...</li>
<li>Use Mark Murphy's <code>LoaderEx</code> library and only make database modifications using the <code>AsyncTask</code> operations his library provides. Note that the reason why his tasks refresh the <code>Loader</code> is because they call <code>onContentChanged</code> on the <code>Loader</code> immediately after the insertion/update/delete is performed, effectively telling the <code>Loader</code> that the content has changed and that it should refresh its data.</li>
<li>Just use a <code>ContentProvider</code> with a <code>CursorLoader</code> and you can use the <code>ContentResolver#notifyChange()</code> method to notify the <code>CursorLoader</code> that a content change has occurred.</li>
</ol>

I'm trying to figure out a better solution, and I'll report back in the future if I ever find/implement one, but for now these will have to do.

blocks|key|410687|text|这是我的解决方案，在我的onCreateLoader中|type|unstyled|depth|inlineStyleRanges|entityRanges|data|410688|{
Uri+u+=+Uri.parse("content://what_string_you_want");
return+new+CursorLoader(this,+yourURI,+projection,+null,+null,+null)+{
++++private+final+ForceLoadContentObserver+mObserver+=+new+ForceLoadContentObserver();

++++@Override
++++public+Cursor+loadInBackground()+{
++++++++Cursor+c+=+YOUR_DATABASE.doYourQuery(...);
++++++++if+(c+!=+null)+{
++++++++++//+Ensure+the+cursor+window+is+filled
+++++++++++c.getCount();
+++++++++++c.registerContentObserver(mObserver);
++++++++}

++++++++c.setNotificationUri(getContext().getContentResolver(),+getUri());
++++++++return+c;
++++}
};
}|code-block|syntax|javascript|410689|在将更改DB的代码之后，添加|410690|+getContentResolver().notifyChange(
++++++++++++Uri.parse("content://same_with_first_string"),+null);|410691|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|$]]

Here is my solution, in my onCreateLoader

<pre><code>{
Uri u = Uri.parse("content://what_string_you_want");
return new CursorLoader(this, yourURI, projection, null, null, null) {
 private final ForceLoadContentObserver mObserver = new ForceLoadContentObserver();

 @Override
 public Cursor loadInBackground() {
 Cursor c = YOUR_DATABASE.doYourQuery(...);
 if (c != null) {
 // Ensure the cursor window is filled
 c.getCount();
 c.registerContentObserver(mObserver);
 }

 c.setNotificationUri(getContext().getContentResolver(), getUri());
 return c;
 }
};
}
</code></pre>

After the code that will change DB, add

<pre><code> getContentResolver().notifyChange(
 Uri.parse("content://same_with_first_string"), null);
</code></pre>

blocks|key|407936|text|将共享首选项中的布尔值设置为false会怎么样？当布尔值为真时更新内容...当任何改变底层数据库的操作..该布尔值将被设置为true，并且作为共享首选项，您可以在调用相关方法后直接接收实时更改|type|unstyled|depth|inlineStyleRanges|entityRanges|data|407937|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|$]]

how about having a boolean in shared preferences as false .. updating the content when that boolean is true....
and when any of the operations which changes the underlying database .. that boolean will be set to true and as shared preferences you a changelistener you can recieve changes live directly after the relevant methods are called

I know this has been discussed yet I wanted to ask about the current state of the matter. Do i have to create a ContentProvider to use CursorLoader in connection with a sqlite database? 

I found

<a href="https://stackoverflow.com/questions/7182485/usage-cursorloader-without-contentprovider/7422343#7422343">CursorLoader usage without ContentProvider</a>

Looks exactly what I was hoping for yet as Emmby commented

<ul>
<li>Users should be aware of one limitation, which is that it has no mechanism to refresh on data changes (as Loaders are supposed to do)</li>
</ul>

So another solution is mentioned 

<a href="https://github.com/commonsguy/cwac-loaderex" rel="nofollow noreferrer">https://github.com/commonsguy/cwac-loaderex</a>

yet again some drawback is pointed out

<ul>
<li>However, to make use of the automatic re-querying, you need to use the same loader for the UI as well as for the updates, limiting its usability for background services.</li>
</ul>

Of course when using LoaderManager we want to get all the benefits for which it was introduced. So my question is if there is a way to use LoaderManager in connection with a sqlite database without having to implement a content provider yet have all the benefits of it.

Thanks

android - CursorLoader & SQLite without Content Provider

数据库

Android

我知道这件事已经讨论过了，但我想问一下事情的现状。我必须创建一个ContentProvider才能将CursorLoader与sqlite数据库结合使用吗？我发现正如Emmby评论的那样，看起来正是我所希望的用户应该注意一个限制，那就是它没有在数据更改时刷新的机制(正如加载器应该做的那样所以这里提到了另一种解决方案但还...

问没有内容提供商的android - CursorLoader & SQLite
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