Form.CancelButton 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

获取或设置当用户按 Esc 键时单击的按钮控件。

public:
 property System::Windows::Forms::IButtonControl ^ CancelButton { System::Windows::Forms::IButtonControl ^ get(); void set(System::Windows::Forms::IButtonControl ^ value); };

public System.Windows.Forms.IButtonControl? CancelButton { get; set; }

member this.CancelButton : System.Windows.Forms.IButtonControl with get, set

Public Property CancelButton As IButtonControl

属性值

IButtonControl

IButtonControl，表示窗体的“取消”按钮。

示例

以下示例创建 的新实例 Form ，并调用 ShowDialog 方法将窗体显示为对话框。 该示例将 FormBorderStyle、AcceptButton、、CancelButtonMinimizeBox、 MaximizeBox和 StartPosition 属性设置为将窗体的外观和功能更改为对话框。 该示例还使用 Add 窗体集合的 Controls 方法添加两个 Button 控件。 该示例使用 HelpButton 属性在对话框的标题栏中显示帮助按钮。

public:
   void CreateMyForm()
   {
      // Create a new instance of the form.
      Form^ form1 = gcnew Form;
      // Create two buttons to use as the accept and cancel buttons.
      Button^ button1 = gcnew Button;
      Button^ button2 = gcnew Button;
      
      // Set the text of button1 to "OK".
      button1->Text = "OK";
      // Set the position of the button on the form.
      button1->Location = Point(10,10);
      // Set the text of button2 to "Cancel".
      button2->Text = "Cancel";
      // Set the position of the button based on the location of button1.
      button2->Location =
         Point( button1->Left, button1->Height + button1->Top + 10 );
      // Set the caption bar text of the form.   
      form1->Text = "My Dialog Box";
      // Display a help button on the form.
      form1->HelpButton = true;
      
      // Define the border style of the form to a dialog box.
      form1->FormBorderStyle = ::FormBorderStyle::FixedDialog;
      // Set the MaximizeBox to false to remove the maximize box.
      form1->MaximizeBox = false;      
      // Set the MinimizeBox to false to remove the minimize box.
      form1->MinimizeBox = false;
      // Set the accept button of the form to button1.
      form1->AcceptButton = button1;
      // Set the cancel button of the form to button2.
      form1->CancelButton = button2;
      // Set the start position of the form to the center of the screen.
      form1->StartPosition = FormStartPosition::CenterScreen;
      
      // Add button1 to the form.
      form1->Controls->Add( button1 );
      // Add button2 to the form.
      form1->Controls->Add( button2 );
      // Display the form as a modal dialog box.
      form1->ShowDialog();
   }

public void CreateMyForm()
{
   // Create a new instance of the form.
   Form form1 = new Form();
   // Create two buttons to use as the accept and cancel buttons.
   Button button1 = new Button ();
   Button button2 = new Button ();
  
   // Set the text of button1 to "OK".
   button1.Text = "OK";
   // Set the position of the button on the form.
   button1.Location = new Point (10, 10);
   // Set the text of button2 to "Cancel".
   button2.Text = "Cancel";
   // Set the position of the button based on the location of button1.
   button2.Location
      = new Point (button1.Left, button1.Height + button1.Top + 10);
   // Set the caption bar text of the form.   
   form1.Text = "My Dialog Box";
   // Display a help button on the form.
   form1.HelpButton = true;

   // Define the border style of the form to a dialog box.
   form1.FormBorderStyle = FormBorderStyle.FixedDialog;
   // Set the MaximizeBox to false to remove the maximize box.
   form1.MaximizeBox = false;
   // Set the MinimizeBox to false to remove the minimize box.
   form1.MinimizeBox = false;
   // Set the accept button of the form to button1.
   form1.AcceptButton = button1;
   // Set the cancel button of the form to button2.
   form1.CancelButton = button2;
   // Set the start position of the form to the center of the screen.
   form1.StartPosition = FormStartPosition.CenterScreen;
   
   // Add button1 to the form.
   form1.Controls.Add(button1);
   // Add button2 to the form.
   form1.Controls.Add(button2);
   
   // Display the form as a modal dialog box.
   form1.ShowDialog();
}

Public Sub CreateMyForm()
    ' Create a new instance of the form.
    Dim form1 As New Form()
    ' Create two buttons to use as the accept and cancel buttons.
    Dim button1 As New Button()
    Dim button2 As New Button()
       
    ' Set the text of button1 to "OK".
    button1.Text = "OK"
    ' Set the position of the button on the form.
    button1.Location = New Point(10, 10)
    ' Set the text of button2 to "Cancel".
    button2.Text = "Cancel"
    ' Set the position of the button based on the location of button1.
    button2.Location = _
       New Point(button1.Left, button1.Height + button1.Top + 10)
    ' Set the caption bar text of the form.   
    form1.Text = "My Dialog Box"
    ' Display a help button on the form.
    form1.HelpButton = True
       
    ' Define the border style of the form to a dialog box.
    form1.FormBorderStyle = FormBorderStyle.FixedDialog
    ' Set the MaximizeBox to false to remove the maximize box.
    form1.MaximizeBox = False
    ' Set the MinimizeBox to false to remove the minimize box.
    form1.MinimizeBox = False
    ' Set the accept button of the form to button1.
    form1.AcceptButton = button1
    ' Set the cancel button of the form to button2.
    form1.CancelButton = button2
    ' Set the start position of the form to the center of the screen.
    form1.StartPosition = FormStartPosition.CenterScreen
       
    ' Add button1 to the form.
    form1.Controls.Add(button1)
    ' Add button2 to the form.
    form1.Controls.Add(button2)
       
    ' Display the form as a modal dialog box.
    form1.ShowDialog()
End Sub

注解

窗体的取消按钮是用户按 ESC 键时单击的按钮控件。 分配给此属性的按钮必须是 IButtonControl 位于当前窗体上或位于当前窗体的容器内的 。

此属性允许指定当用户在应用程序中按 ESC 键时发生的默认操作。 可以使用此属性，让用户只需按 ESC 键即可关闭窗口而不提交更改，而无需用鼠标手动单击“取消”按钮，从而允许用户快速导航简单窗体。

CancelButton 如果窗体上的另一个控件截获 ESC 键，则可能不起作用。 例如，如果在窗体上打开了 ， ComboBox 则 ESC 会关闭 而不是 ComboBox 关闭窗体。

IButtonControl分配给 CancelButton 的对象必须在窗体上可见，否则按 ESC 键将不起作用。

另请参阅

• AcceptButton
• IButtonControl