Form.CancelButton 属性

定义

获取或设置当用户按 Esc 键时单击的按钮控件。Gets or sets the button control that is clicked when the user presses the ESC key.

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,表示窗体的“取消”按钮。An IButtonControl that represents the cancel button for the form.

示例

下面的示例创建 Form 的新实例,并调用 ShowDialog 方法将窗体显示为对话框。The following example creates a new instance of a Form and calls the ShowDialog method to display the form as a dialog box. 该示例设置了 "FormBorderStyle"、"AcceptButton"、"CancelButton"、"MinimizeBox"、"MaximizeBox" 和 "StartPosition" 属性,将窗体的外观和功能更改为对话框。The example sets the FormBorderStyle, AcceptButton, CancelButton, MinimizeBox, MaximizeBox, and StartPosition properties to change the appearance and functionality of the form to a dialog box. 该示例还使用窗体的 Controls 集合的 Add 方法来添加两个 Button 控件。The example also uses the Add method of the form's Controls collection to add two Button controls. 该示例使用 HelpButton 属性在对话框的标题栏中显示 "帮助" 按钮。The example uses the HelpButton property to display a help button in the caption bar of the dialog box.

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 ESC 键时单击的按钮控件。The cancel button for a form is the button control that is clicked whenever the user presses the ESC key. 分配给此属性的按钮必须是当前窗体上或位于当前窗体上的容器中的 IButtonControlThe button assigned to this property must be an IButtonControl that is on the current form or located within a container on the current form.

使用此属性,可以指定当用户在应用程序中按 ESC 键时要发生的默认操作。This property allows you to designate a default action to occur when the user presses the ESC key in your application. 您可以使用此属性来允许用户在简单的窗体中快速导航,只需按 ESC 键即可关闭窗口而不提交更改,而不是使用鼠标手动单击 "取消" 按钮。You can use this property to allow the user to quickly navigate a simple form by allowing them to simply press the ESC key to close a window without committing changes instead of manually clicking the cancel button with their mouse.

如果窗体上的另一个控件截获 ESC 键,则 CancelButton 可能不起作用。CancelButton may not work if another control on the form intercepts the ESC key. 例如,如果在窗体上打开 ComboBox,则 ESC 将关闭 ComboBox 而不是关闭窗体。For example, if you have a ComboBox open on your form, ESC will close the ComboBox instead of closing the Form.

分配给 CancelButtonIButtonControl 对象必须在窗体上可见,否则按 ESC 键将不起作用。The IButtonControl object assigned to CancelButton must be visible on the form, or else pressing the ESC key will have no effect.

适用于

另请参阅