Form.CancelButton 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

Source:

Form.cs

获取或设置当用户按下 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

一个 IButtonControl 表示窗体的取消按钮。

示例

以下示例创建一个新实例 Form ，并调用 ShowDialog 该方法以对话框形式显示窗体。 该示例将窗体的外观和功能更改为对话框的 FormBorderStyle、AcceptButtonCancelButton、、MinimizeBox和MaximizeBoxStartPosition属性。 该示例还使用 Add 窗体 Controls 集合的方法添加两 Button 个控件。 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

窗体的取消按钮是每当用户按下 ESC 键时单击的按钮控件。 分配给此属性的按钮必须是 IButtonControl 当前窗体上或位于当前窗体上的容器中的按钮。

此属性允许你在应用程序中按 ESC 键时指定默认操作。 可以使用此属性让用户快速导航简单窗体，方法是允许他们直接按 ESC 键关闭窗口，而无需提交更改，而无需使用鼠标手动单击取消按钮。

CancelButton 如果窗体上的另一个控件截获 ESC 键，则可能无法正常工作。 例如，如果在窗体上打开， ComboBox ESC 将关闭 ComboBox 而不是关闭窗体。

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