MenuItem.Checked 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

取得或設定值，指出功能表項目的文字旁邊要不要顯示核取記號。

public:
 property bool Checked { bool get(); void set(bool value); };

public bool Checked { get; set; }

member this.Checked : bool with get, set

Public Property Checked As Boolean

屬性值

Boolean

如果功能表項目旁邊有核取記號，則為 true，否則為 false。 預設為 false。

例外狀況

ArgumentException

MenuItem 為最上層功能表或是具有子系。

範例

下列程式碼範例會 Checked 使用 屬性來提供應用程式中的狀態。 在此範例中，會使用一組功能表項目來指定控制項中 TextBox 文字的色彩。 提供的事件處理常式是由 Click 三個功能表項目的事件使用。 每個功能表項目都會指定文字色彩、 menuItemRed (紅色) 、 menuItemGreen (綠色) ，或 menuItemBlue (藍色) 。 事件處理常式會決定按下哪一個功能表項目、將核取記號放在選取的功能表項目，以及變更表單控制項的 TextBox 文字色彩。 此範例要求命名空間 System.Drawing 已新增至此程式碼所在的表單。 此範例也需要 TextBox 已將 新增至這個範例程式碼所在的表單，該表單名為 textBox1 。

private:
   // The following event handler would be connected to three menu items.
   void MyMenuClick( Object^ sender, EventArgs^ e )
   {
      // Determine if clicked menu item is the Blue menu item.
      if ( sender == menuItemBlue )
      {
         // Set the checkmark for the menuItemBlue menu item.
         menuItemBlue->Checked = true;
         // Uncheck the menuItemRed and menuItemGreen menu items.
         menuItemRed->Checked = false;
         menuItemGreen->Checked = false;
         // Set the color of the text in the TextBox control to Blue.
         textBox1->ForeColor = Color::Blue;
      }
      else if ( sender == menuItemRed )
      {
         
         // Set the checkmark for the menuItemRed menu item.
         menuItemRed->Checked = true;
         // Uncheck the menuItemBlue and menuItemGreen menu items.
         menuItemBlue->Checked = false;
         menuItemGreen->Checked = false;
         // Set the color of the text in the TextBox control to Red.
         textBox1->ForeColor = Color::Red;
      }
      else
      {
         // Set the checkmark for the menuItemGreen.
         menuItemGreen->Checked = true;
         // Uncheck the menuItemRed and menuItemBlue menu items.
         menuItemBlue->Checked = false;
         menuItemRed->Checked = false;
         // Set the color of the text in the TextBox control to Blue.
         textBox1->ForeColor = Color::Green;
      }
   }

// The following event handler would be connected to three menu items.
 private void MyMenuClick(Object sender, EventArgs e)
 {
    // Determine if clicked menu item is the Blue menu item.
    if(sender == menuItemBlue)
    {
       // Set the checkmark for the menuItemBlue menu item.
       menuItemBlue.Checked = true;
       // Uncheck the menuItemRed and menuItemGreen menu items.
       menuItemRed.Checked = false;
       menuItemGreen.Checked = false;
       // Set the color of the text in the TextBox control to Blue.
       textBox1.ForeColor = Color.Blue;
    }
    else if(sender == menuItemRed)
    {
       // Set the checkmark for the menuItemRed menu item.
       menuItemRed.Checked = true;
       // Uncheck the menuItemBlue and menuItemGreen menu items.
       menuItemBlue.Checked = false;
       menuItemGreen.Checked = false;
       // Set the color of the text in the TextBox control to Red.
       textBox1.ForeColor = Color.Red;
    }
    else
    {
       // Set the checkmark for the menuItemGreen.
       menuItemGreen.Checked = true;
       // Uncheck the menuItemRed and menuItemBlue menu items.
       menuItemBlue.Checked = false;
       menuItemRed.Checked = false;
       // Set the color of the text in the TextBox control to Blue.
       textBox1.ForeColor = Color.Green;
    }
 }

' The following event handler would be connected to three menu items.
Private Sub MyMenuClick(sender As Object, e As EventArgs)
    ' Determine if clicked menu item is the Blue menu item.
    If sender Is menuItemBlue Then
        ' Set the checkmark for the menuItemBlue menu item.
        menuItemBlue.Checked = True
        ' Uncheck the menuItemRed and menuItemGreen menu items.
        menuItemRed.Checked = False
        menuItemGreen.Checked = False
        ' Set the color of the text in the TextBox control to Blue.
        textBox1.ForeColor = Color.Blue
    Else
        If sender Is menuItemRed Then
            ' Set the checkmark for the menuItemRed menu item.
            menuItemRed.Checked = True
            ' Uncheck the menuItemBlue and menuItemGreen menu items.
            menuItemBlue.Checked = False
            menuItemGreen.Checked = False
            ' Set the color of the text in the TextBox control to Red.
            textBox1.ForeColor = Color.Red
        Else
            ' Set the checkmark for the menuItemGreen.
            menuItemGreen.Checked = True
            ' Uncheck the menuItemRed and menuItemBlue menu items.
            menuItemBlue.Checked = False
            menuItemRed.Checked = False
            ' Set the color of the text in the TextBox control to Blue.
            textBox1.ForeColor = Color.Green
        End If
    End If
End Sub

備註

您可以將 Checked 屬性與功能表中的其他功能表項目搭配使用，以提供應用程式的狀態。 例如，您可以將核取記號放在一組專案的功能表項目上，以識別應用程式中要針對文字顯示的字型大小。 您也可以使用 Checked 屬性來識別一組互斥功能表項目中選取的功能表項目。

注意

無法針對最上層功能表項目將此屬性設定為 true 。