blocks|key|664600|text|当您更改数据库中希望反映在Cursor中的数据(或Cursor填充的内容，如通过CursorAdapter生成的ListView+)时，在Cursor上调用requery()。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|664601|Cursor类似于ODBC客户端游标--它保存查询结果表示的所有数据。因此，仅仅因为您更改了数据库中的数据，Cursor就不会知道这些更改，除非您通过requery()刷新它。|664602|664603|更新：由于年龄增长，整个问题和答案都应该删除，但这显然是不可能的。任何寻找Android答案的人都应该记住，Android是一个快速移动的目标，2009年的答案通常比新的答案更糟糕。|BOLD|664604|当前的解决方案是获取一个新的Cursor，并在CursorAdapter上使用changeCursor()或swapCursor()来影响数据更改。|664605|entityMap^0|D|6|P|6|14|D|1K|8|1X|6|26|9|0|0|6|1I|6|23|9|0|0|0|2|0|E|6|N|D|13|E|1I|C|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]|$9|S|A|T|B|C]|$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|19|8|@]|D|@]|E|$]]|$1|I|3|J|5|6|7|1A|8|@$9|1B|A|1C|B|K]]|D|@]|E|$]]|$1|L|3|M|5|6|7|1D|8|@$9|1E|A|1F|B|C]|$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|1M|8|@]|D|@]|E|$]]]|O|$]]

Call <code>requery()</code> on the <code>Cursor</code> when you change data in the database that you want reflected in that <code>Cursor</code> (or things the <code>Cursor</code> populates, like a <code>ListView</code> via a <code>CursorAdapter</code>).

A <code>Cursor</code> is akin to an ODBC client-side cursor -- it holds all of the data represented by the query result. Hence, just because you change the data in the database, the <code>Cursor</code> will not know about those changes unless you refresh it via <code>requery()</code>.

<hr>

UPDATE: This whole question and set of answers should be deleted due to old age, but that's apparently impossible. Anyone seeking Android answers should bear in mind that the Android is a swiftly-moving target, and answers from 2009 are typically worse than are newer answers.

The current solution is to obtain a fresh <code>Cursor</code> and use either <code>changeCursor()</code> or <code>swapCursor()</code> on the <code>CursorAdapter</code> to affect a data change.

blocks|key|797496|text|requery现在已弃用。从documentation|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|797497|797498|此方法已弃用。不要用这个。只需请求一个新游标，这样您就可以异步执行此操作，并在新游标返回时更新列表视图。|blockquote|797499|797500|797501|在获得新的游标之后，可以使用adapter.changeCursor(cursor)。这应该会更新视图。|797502|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/database/Cursor.html#requery%2528%2529^0|0|7|E|D|0|0|0|0|0|0|E|S|0^^$0|@$1|2|3|4|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@$9|Y|A|Z|1|10]]|E|$]]|$1|F|3|-4|5|6|7|11|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|12|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|13|8|@]|D|@]|E|$]]|$1|K|3|-4|5|6|7|14|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|15|8|@$9|16|A|17|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|18|8|@]|D|@]|E|$]]]|O|$P|$5|Q|R|S|E|$T|U]]]]

<code>requery</code> is now deprecated. from the <a href="http://developer.android.com/reference/android/database/Cursor.html#requery%28%29">documentation</a>:

<blockquote>
 This method is deprecated.
 Don't use this. Just request a new cursor, so you can do this asynchronously and update your list view once the new cursor comes back.
</blockquote>

after obtaining a new cursor one can use the<code>adapter.changeCursor(cursor)</code>. this should update the view.

blocks|key|665301|text|如果使用加载器和自动生成的游标，您可以调用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|665302|getLoaderManager().restartLoader(0,+null,+this);|code-block|syntax|javascript|665303|在您的活动中，在DB上更改某些内容后，重新生成新的游标。别忘了还定义了事件处理程序：|665304|@Override
public+Loader<Cursor>+onCreateLoader(int+id,+Bundle+args)+{
++++CursorLoader+cursorLoader+=
++++++++++++new+CursorLoader(this,
++++++++++++++++++++YOUR_URI,
++++++++++++++++++++YOUR_PROJECTION,+null,+null,+null);
++++return+cursorLoader;
}

@Override
public+void+onLoadFinished(Loader<Cursor>+loader,+Cursor+data)+{
++++adapter.swapCursor(data);
}

@Override
public+void+onLoaderReset(Loader<Cursor>+loader)+{
++++adapter.swapCursor(null);
}|665305|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|$]]

In case of using loader and automagically generated cursor you can call:

<pre><code>getLoaderManager().restartLoader(0, null, this);
</code></pre>

in your activity, just after changing something on a DB, to regenerate new cursor.
Don't forget to also have event handlers defined:

<pre><code>@Override
public Loader&lt;Cursor&gt; onCreateLoader(int id, Bundle args) {
 CursorLoader cursorLoader =
 new CursorLoader(this,
 YOUR_URI,
 YOUR_PROJECTION, null, null, null);
 return cursorLoader;
}

@Override
public void onLoadFinished(Loader&lt;Cursor&gt; loader, Cursor data) {
 adapter.swapCursor(data);
}

@Override
public void onLoaderReset(Loader&lt;Cursor&gt; loader) {
 adapter.swapCursor(null);
}
</code></pre>

blocks|key|1965608|text|我不清楚是否将CursorAdapter的autoRequery属性设置为true。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1965609|适配器将检查autoRequery属性；如果该属性为false，则不会更改光标。|1965610|entityMap^0|L|B|11|4|0|6|B|Q|5|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|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|I|$]]

I am not clear if you set the <code>autoRequery</code> property of CursorAdapter to <code>true</code>.

The adapter will check the <code>autoRequery</code> property; if it is <code>false</code>, then the cursor will not be changed.

blocks|key|797627|text|requery()已被弃用，只需在CursorAdapter的子类中实现如下简单的updateUI()方法，并在数据更新后调用它：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|797628|private+void+updateUI(){
++++swapCursor(dbHelper.getCursor());
++++notifyDataSetChanged();
}|code-block|syntax|javascript|797629|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|$]]

requery() is already deprecated, just implement the simple updateUI() method like this in your CursorAdapter's child class and call it after data updates:

<pre><code>private void updateUI(){
 swapCursor(dbHelper.getCursor());
 notifyDataSetChanged();
}
</code></pre>

blocks|key|664686|text|很简单。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|664687|private+Db+mDbAdapter;
private+Cursor+mCursor;
private+SimpleCursorAdapter+mCursorAd;

.....................................
//After+removing+the+item+from+the+DB,+use+this
.....................................

+mCursor+=+mDbAdapter.getAllItems();
+mCursorAd.swapCursor(mCursor);|code-block|syntax|javascript|664688|或者使用CursorLoader...|664689|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

It's easy. 

<pre><code>private Db mDbAdapter;
private Cursor mCursor;
private SimpleCursorAdapter mCursorAd;

.....................................
//After removing the item from the DB, use this
.....................................

 mCursor = mDbAdapter.getAllItems();
 mCursorAd.swapCursor(mCursor);
</code></pre>

Or use CursorLoader...

I have an Android <code>ListActivity</code> that is backed by a database <code>Cursor</code> through a <code>SimpleCursorAdapter</code>.

When the items are clicked, a flag field in the coresponding row in the database is toggled and the view in the list needs to be updated. 

The problem is, when the view that's updated goes off screen and is recycled, the old value is displayed on the view when it returns into view. The same thing happens whenever thr list is redrawb (orientation changes, etc). 

I use <code>notifydatasetchanged()</code> to refresh the cursor adapter but it seems ineffective.

How should I be updating the database so the cursor is updated as well?

Android SimpleCursorAdapter doesn't update when database changes

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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我有一个由数据库Cursor通过SimpleCursorAdapter支持的安卓ListActivity。单击这些项时，数据库中相应行中的标志字段将被切换，并且需要更新列表中的视图。问题是，当更新的视图离开屏幕并被回收时，当视图返回视图时，旧值会显示在视图上。当列表被重新绘制时，同样的事情也会发生(方向改变，等等)。我...

问当数据库更改时，安卓SimpleCursorAdapter不会更新
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问当数据库更改时，安卓SimpleCursorAdapter不会更新EN