ListBox.ClearSelected 方法

定义

取消选择 ListBox 中的所有项。Unselects all items in the ListBox.

public:
 void ClearSelected();
public void ClearSelected ();
member this.ClearSelected : unit -> unit
Public Sub ClearSelected ()

示例

下面的代码示例演示如何将 SelectedIndex 属性与 TopIndex 属性一起使用,以将当前选定项移到 ListBox显示区域中项列表的顶部。The following code example demonstrates how to use the SelectedIndex property with the TopIndex property to move the currently selected item to the top of the list of items in the display area of the ListBox. 该示例还演示了如何使用 System.Windows.Forms.ListBox.ObjectCollection 类的 RemoveAt 方法删除项,以及如何使用 ClearSelected 方法清除所有项选择。The example further demonstrates how to remove items using the RemoveAt method of the System.Windows.Forms.ListBox.ObjectCollection class, and how to clear all item selection using the ClearSelected method. 代码首先将 ListBox 中当前选定的项移动到列表的顶部。The code first moves the currently selected item in the ListBox to the top of the list. 然后,该代码移除当前选定项之前的所有项,并清除 ListBox中的所有选择。The code then removes all items before the currently selected item and clears all selections in the ListBox. 此示例要求将包含项的 ListBox 添加到窗体中,并且当前在 ListBox中选择了该项。This example requires that a ListBox containing items is added to a form and that an item is currently selected in the ListBox.

private:
   void RemoveTopItems()
   {
      // Determine if the currently selected item in the ListBox 
      // is the item displayed at the top in the ListBox.
      if ( listBox1->TopIndex != listBox1->SelectedIndex )

      // Make the currently selected item the top item in the ListBox.
      listBox1->TopIndex = listBox1->SelectedIndex;

      // Remove all items before the top item in the ListBox.
      for ( int x = (listBox1->SelectedIndex - 1); x >= 0; x-- )
      {
         listBox1->Items->RemoveAt( x );
      }

      // Clear all selections in the ListBox.
      listBox1->ClearSelected();
   }
private void RemoveTopItems()
{
   // Determine if the currently selected item in the ListBox 
   // is the item displayed at the top in the ListBox.
   if (listBox1.TopIndex != listBox1.SelectedIndex)
      // Make the currently selected item the top item in the ListBox.
      listBox1.TopIndex = listBox1.SelectedIndex;

   // Remove all items before the top item in the ListBox.
   for (int x = (listBox1.SelectedIndex -1); x >= 0; x--)
   {
      listBox1.Items.RemoveAt(x);
   }

   // Clear all selections in the ListBox.
   listBox1.ClearSelected();
}
Private Sub RemoveTopItems()
   ' Determine if the currently selected item in the ListBox 
   ' is the item displayed at the top in the ListBox.
   If listBox1.TopIndex <> listBox1.SelectedIndex Then
      ' Make the currently selected item the top item in the ListBox.
      listBox1.TopIndex = listBox1.SelectedIndex
   End If
   ' Remove all items before the top item in the ListBox.
   Dim x As Integer
   For x = listBox1.SelectedIndex - 1 To 0 Step -1
      listBox1.Items.RemoveAt(x)
   Next x

   ' Clear all selections in the ListBox.
   listBox1.ClearSelected()
End Sub

注解

调用此方法等效于将 SelectedIndex 属性设置为负一(-1)。Calling this method is equivalent to setting the SelectedIndex property to negative one (-1). 您可以使用此方法快速取消选择列表中的所有项。You can use this method to quickly unselect all items in the list.

适用于

另请参阅