ListBox.SelectionMode 属性

项目
08/17/2007

获取或设置在 ListBox 中选择项所用的方法。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Public Overridable Property SelectionMode As SelectionMode
用法
Dim instance As ListBox
Dim value As SelectionMode

value = instance.SelectionMode

instance.SelectionMode = value

public virtual SelectionMode SelectionMode { get; set; }

public:
virtual property SelectionMode SelectionMode {
    SelectionMode get ();
    void set (SelectionMode value);
}

/** @property */
public SelectionMode get_SelectionMode ()

/** @property */
public void set_SelectionMode (SelectionMode value)

public function get SelectionMode () : SelectionMode

public function set SelectionMode (value : SelectionMode)

属性值

SelectionMode 值之一。默认为 SelectionMode.One。

异常

异常类型	条件
InvalidEnumArgumentException	分配的值不是 SelectionMode 值之一。

备注

SelectionMode 属性使您得以确定用户一次可选择 ListBox 中的多少个项以及用户可如何进行多重选择。当 SelectionMode 属性设置为 SelectionMode.MultiExtended 时，按下 Shift 键的同时单击鼠标或者同时 Shift 键和箭头键之一（向上键、向下键、向左键和向右键），会将选定内容从前一选定项扩展到当前项。按 Ctrl 键的同时单击鼠标将选择或撤消选择列表中的某项。当该属性设置为 SelectionMode.MultiSimple 时，鼠标单击或按空格键将选择或撤消选择列表中的某项。

示例

下面的代码示例演示如何使用 GetSelected 方法来确定已选择了 ListBox 中的哪些项，以便选择那些尚未选定的项及取消选择那些已选定的项。该示例还演示了如何使用 SelectionMode 属性以使 ListBox 能够有多个选定的项，并使用 Sorted 属性演示了如何对 ListBox 中的项进行自动排序。此示例要求已将名为 listBox1 的 ListBox 添加到窗体，并要求从该窗体的 Load 事件调用在该示例中定义的 InitializeMyListBox 方法。

Private Sub InitializeMyListBox()
   ' Add items to the ListBox.
   listBox1.Items.Add("A")
   listBox1.Items.Add("C")
   listBox1.Items.Add("E")
   listBox1.Items.Add("F")
   listBox1.Items.Add("G")
   listBox1.Items.Add("D")
   listBox1.Items.Add("B")

   ' Sort all items added previously.
   listBox1.Sorted = True

   ' Set the SelectionMode to select multiple items.
   listBox1.SelectionMode = SelectionMode.MultiExtended

   ' Select three initial items from the list.
   listBox1.SetSelected(0, True)
   listBox1.SetSelected(2, True)
   listBox1.SetSelected(4, True)

   ' Force the ListBox to scroll back to the top of the list.
   listBox1.TopIndex = 0
End Sub

Private Sub InvertMySelection()

   Dim x As Integer
   ' Loop through all items the ListBox.
   For x = 0 To listBox1.Items.Count - 1

      ' Determine if the item is selected.
      If listBox1.GetSelected(x) = True Then
         ' Deselect all items that are selected.
         listBox1.SetSelected(x, False)
      Else
         ' Select all items that are not selected.
         listBox1.SetSelected(x, True)
      End If
   Next x
   ' Force the ListBox to scroll back to the top of the list.
   listBox1.TopIndex = 0
End Sub

private void InitializeMyListBox()
{
   // Add items to the ListBox.
   listBox1.Items.Add("A");
   listBox1.Items.Add("C");
   listBox1.Items.Add("E");
   listBox1.Items.Add("F");
   listBox1.Items.Add("G");
   listBox1.Items.Add("D");
   listBox1.Items.Add("B");

   // Sort all items added previously.
   listBox1.Sorted = true;

   // Set the SelectionMode to select multiple items.
   listBox1.SelectionMode = SelectionMode.MultiExtended;

   // Select three initial items from the list.
   listBox1.SetSelected(0,true);
   listBox1.SetSelected(2,true);
   listBox1.SetSelected(4,true);

   // Force the ListBox to scroll back to the top of the list.
   listBox1.TopIndex=0;
}

private void InvertMySelection()
{
   // Loop through all items the ListBox.
   for (int x = 0; x < listBox1.Items.Count; x++)
   {
      // Determine if the item is selected.
      if(listBox1.GetSelected(x) == true)
         // Deselect all items that are selected.
         listBox1.SetSelected(x,false);      
      else
         // Select all items that are not selected.
         listBox1.SetSelected(x,true);
   }
   // Force the ListBox to scroll back to the top of the list.
   listBox1.TopIndex=0;
}

private:
   void InitializeMyListBox()
   {
      // Add items to the ListBox.
      listBox1->Items->Add( "A" );
      listBox1->Items->Add( "C" );
      listBox1->Items->Add( "E" );
      listBox1->Items->Add( "F" );
      listBox1->Items->Add( "G" );
      listBox1->Items->Add( "D" );
      listBox1->Items->Add( "B" );

      // Sort all items added previously.
      listBox1->Sorted = true;

      // Set the SelectionMode to select multiple items.
      listBox1->SelectionMode = SelectionMode::MultiExtended;

      // Select three initial items from the list.
      listBox1->SetSelected( 0, true );
      listBox1->SetSelected( 2, true );
      listBox1->SetSelected( 4, true );

      // Force the ListBox to scroll back to the top of the list.
      listBox1->TopIndex = 0;
   }

   void InvertMySelection()
   {
      // Loop through all items the ListBox.
      for ( int x = 0; x < listBox1->Items->Count; x++ )
      {
         // Select all items that are not selected,
         // deselect all items that are selected.
         listBox1->SetSelected( x,  !listBox1->GetSelected( x ) );
      }
      listBox1->TopIndex = 0;
   }

private void InitializeMyListBox()
{
    // Add items to the ListBox.
    listBox1.get_Items().Add("A");
    listBox1.get_Items().Add("C");
    listBox1.get_Items().Add("E");
    listBox1.get_Items().Add("F");
    listBox1.get_Items().Add("G");
    listBox1.get_Items().Add("D");
    listBox1.get_Items().Add("B");

    // Sort all items added previously.
    listBox1.set_Sorted(true);

    // Set the SelectionMode to select multiple items.
    listBox1.set_SelectionMode(SelectionMode.MultiExtended);

    // Select three initial items from the list.
    listBox1.SetSelected(0, true);
    listBox1.SetSelected(2, true);
    listBox1.SetSelected(4, true);

    // Force the ListBox to scroll back to the top of the list.
    listBox1.set_TopIndex(0);
} //InitializeMyListBox

private void InvertMySelection()
{
    // Loop through all items the ListBox.
    for (int x = 0; x < listBox1.get_Items().get_Count(); x++) {
        // Determine if the item is selected.
        if (listBox1.GetSelected(x) == true) {
            // Deselect all items that are selected.
            listBox1.SetSelected(x, false);
        }        
        else {
            // Select all items that are not selected.
            listBox1.SetSelected(x, true);
        }
    }
    // Force the ListBox to scroll back to the top of the list.
    listBox1.set_TopIndex(0);
} //InvertMySelection

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

通过

ListBox.SelectionMode 属性

语法

属性值

异常

备注

示例

平台

版本信息

.NET Framework

请参见

参考

其他资源