我有以下代码。 我想要实现的是当我单击一个条目时更新显示的列表,以便遍历列表。 我发现了两个未注释的方法来做到这一点在stackoverflow,但都没有工作。 我也收到了关于在数据更新上创建一个新的ListActivity的建议,但这听起来像浪费资源?如何更新Android ListActivity更改连接的SimpleCursorAdapter的数据
编辑:我自己找到了解决方案。所有你需要做的就是调用“SimpleCursorAdapter.changeCursor(new Cursor);”。没有通知,UI-Thread中没有任何东西。
import android.app.ListActivity;
import android.database.Cursor;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
public class MyActivity extends ListActivity {
private DepartmentDbAdapter mDbHelper;
private Cursor cursor;
private String[] from = new String[] { DepartmentDbAdapter.KEY_NAME };
private int[] to = new int[] { R.id.text1 };
private SimpleCursorAdapter notes;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.departments_list);
mDbHelper = new DepartmentDbAdapter(this);
mDbHelper.open();
// Get all of the departments from the database and create the item list
cursor = mDbHelper.fetchSubItemByParentId(1);
this.startManagingCursor(cursor);
// Now create an array adapter and set it to display using our row
notes = new SimpleCursorAdapter(this, R.layout.department_row, cursor, from, to);
this.setListAdapter(notes);
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
// get new data and update the list
this.updateData(safeLongToInt(id));
}
/**
* update data for the list
*
* @param int departmentId id of the parent department
*/
private void updateData(int departmentId) {
// close the old one, get a new one
cursor.close();
cursor = mDbHelper.fetchSubItemByParentId(departmentId);
// change the cursor of the adapter to the new one
notes.changeCursor(cursor);
}
/**
* safely convert long to in to save memory
*
* @param long l the long variable
*
* @return integer
*/
public static int safeLongToInt(long l) {
if (l < Integer.MIN_VALUE || l > Integer.MAX_VALUE) {
throw new IllegalArgumentException
(l + " cannot be cast to int without changing its value.");
}
return (int) l;
}
}
我改变了了updateData功能,这一点没有任何用处,我搜索我的屁股找到如何做到这一点,要找到一个例子,教程...没有。因为我试图让这个工作2天,所以感到沮丧。不能相信没有人有过这个问题! \t private void updateData(int departmentId){\t \t \t this.stopManagingCursor(cursor); \t \t cursor.close(); \t \t cursor = mDbHelper.fetchSubItemByParentId(departmentId); \t \t this.startManagingCursor(cursor); \t \t SimpleCursorAdapter notes = new SimpleCursorAdapter(this,R.layout.department_row,cursor,from,to); \t \t this.setListAdapter(notes); \t} – DarsVaeda 2012-03-29 22:16:53
请更新您的代码。我今天会照顾它。 – Snicolas 2012-03-30 07:12:13
你不远,现在应该接近工作 – Snicolas 2012-03-30 07:12:31