经过对数据库的修改我如何刷新我的ListView？ [英] How do I refresh my ListView after the database changes?

问题描述

我想在Android应用程序管理一个简单的列表。该列表的内容被保持在SQLite数据库。当用户选择并保持在一个特定的行，显示上下文菜单与一个删除选项。当他们选择删除，该行从数据库中删除，但认为不会刷新。当我回到了应用程序，并在回来后，相应的行已被删除。所以，我知道行被删除，它只是一个不刷新的ListView。

I am trying to manage a simple list in an Android application. The contents of the list are maintained in a SQLite database. When the user selects and holds on a specific row, a context menu appears with a "Delete" option. When they select "Delete", the row is deleted from the database, but the view does not refresh. When I back out of the application and get back in, the appropriate row has been removed. So, I know the row is deleted, it's just the ListView that doesn't refresh.

下面是$相关位c $ C ...

Here are the relevant bits of code...

在onCreate方法...

In the onCreate method...

SQLiteDatabase db = tasks.getReadableDatabase();
Cursor cursor = db.query(TABLE_NAME, 
    new String[] { _ID, TITLE, DETAILS, }, 
    null, null, null, null, TITLE + " DESC");
startManagingCursor(cursor);

ListView lv = (ListView) findViewById(R.id.list);
lv.setAdapter(new SimpleCursorAdapter(this, 
    android.R.layout.simple_list_item_1,
    cursor,
    new String[] {TITLE},
    new int[] { android.R.id.text1}
));

在onContextItemSelected方法...

In the onContextItemSelected method...

switch(item.getItemId()) {
case 0:
    SQLiteDatabase db = tasks.getWritableDatabase();
    ListView lv = (ListView) findViewById(R.id.list);
    SimpleCursorAdapter adapter = (SimpleCursorAdapter) lv.getAdapter();
    db.delete(TABLE_NAME, "_ID=?", new String[] {adapter.getCursor().getString(0)});
    adapter.notifyDataSetChanged(); // Not working, clears screen and doesn't reload
    return true;
}
return super.onContextItemSelected(item);

我在想什么？

What am I missing?

谢谢！

推荐答案

摆脱 notifyDataSetChanged（）并调用重新查询（）<的/ code>在光标。 这里是证明这是一个示例项目。

Get rid of the notifyDataSetChanged() and call requery() on your Cursor. Here is a sample project demonstrating this.

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