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获取选中的项目位置 () 总是返回 - 1
原标题:getSelectedItemPosition() always return -1

我有一个班级,可以延长 清单活动,它的工作很好

然后在 ListTroundClick () 中, 我使用“ 获取选中的项目位置” (), 并总是返回 - 1 。

P.S 获得选中的项目Id () 返回一些长的号码, 如 9943934 。

public class TasksShowActivity  extends ListActivity {

    private Cursor mCursor; 
    private ListAdapter mAdapter;

    private static final String[] mContent = new String[] {
        TasksDbHelper._ID, TasksDbHelper.NAME,
        TasksDbHelper.USER};

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);     

        mCursor = managedQuery(
                TasksProvider.CONTENT_URI, mContent, null, null, null);

        mAdapter = new SimpleCursorAdapter(this, 
                    R.layout.tasks, mCursor, 
                    new String[] {TasksDbHelper.NAME, TasksDbHelper.USER}, 
                    new int[] {R.id.name, R.id.date});

        setListAdapter(mAdapter);
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, final long id) {
        super.onListItemClick(l, v, position, id);

      Toast toast = Toast.makeText(this, "Position: "+this.getSelectedItemPosition() , Toast.LENGTH_SHORT);
            toast.setGravity(Gravity.CENTER, 0, 0);
            toast.show();
    }
}

布局 :

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/tasks_root_element">

    <TextView
        android:id="@+id/name"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true" 
        android:textSize="18sp"
        />
    <TextView
        android:id="@+id/date"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:layout_alignParentRight="true"
        android:textSize="18sp" 
        android:paddingRight="10px"
        />

</RelativeLayout>
问题回答

然后在 ListTroundClick () 中, 我使用“ 获取选中的项目位置” (), 并总是返回 - 1 。

这是因为没有选择任何事物。 “ 点击” 和“ 选择” 是不同的事物。 在 < code> ListView 中, “ 选择” 是通过指针设备( D- Pad, trackball, 箭头键等) 完成的 。





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