listView焦点有关问题

public void onItemSelected(AdapterView<?> listView, View view, int position, long id) 
{ 
    if (position == 1) 
    { 
        // listView.setItemsCanFocus(true); 
 
        // Use afterDescendants, because I don't want the ListView to steal focus 
        listView.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS); 
        myEditText.requestFocus(); 
    } 
    else 
    { 
        if (!listView.isFocused()) 
        { 
            // listView.setItemsCanFocus(false); 
 
            // Use beforeDescendants so that the EditText doesn't re-take focus 
            listView.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); 
            listView.requestFocus(); 
        } 
    } 
} 
 
public void onNothingSelected(AdapterView<?> listView) 
{ 
    // This happens when you start scrolling, so we need to prevent it from staying 
    // in the afterDescendants mode if the EditText was focused  
    listView.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); 
} 

有时候根据需要 <ListView 
    android:id="@android:id/list"  
    android:layout_height="fill_parent"  
    android:layout_width="fill_parent" 
    android:descendantFocusability="beforeDescendants" 
    /> 
主要是 android:descendantFocusability属性的使用