Form.TopMost 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

获取或设置一个值，指示该窗体是否应显示为最顶层窗体。

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

public bool TopMost { get; set; }

member this.TopMost : bool with get, set

Public Property TopMost As Boolean

属性值

Boolean

如果将窗体显示为最顶层窗体，则为 true；否则为 false。 默认值为 false。

示例

以下示例演示如何创建最顶层的窗体。 该示例创建两个窗体，一个是最大化的，一个将显示为最顶部的窗体。 第一个名为 bottomForm的窗体使用 WindowState 属性以最大化方式显示，以更好地演示最顶部窗体的能力。 第二个窗体名为 topMostForm，将 TopMost 属性设置为 true 以将窗体显示为最顶部的窗体。 运行此代码时，单击最大化的窗体不会导致最顶部的窗体显示在最大化窗体的下方。 该示例要求从另一个窗体调用示例中定义的 方法。

private:
   void CreateMyTopMostForm()
   {
      // Create lower form to display.
      Form^ bottomForm = gcnew Form;

      // Display the lower form Maximized to demonstrate effect of TopMost property.
      bottomForm->WindowState = FormWindowState::Maximized;

      // Display the bottom form.
      bottomForm->Show();

      // Create the top most form.
      Form^ topMostForm = gcnew Form;

      // Set the size of the form larger than the default size.
      topMostForm->Size = System::Drawing::Size( 300, 300 );

      // Set the position of the top most form to center of screen.
      topMostForm->StartPosition = FormStartPosition::CenterScreen;

      // Display the form as top most form.
      topMostForm->TopMost = true;
      topMostForm->Show();
   }

private void CreateMyTopMostForm()
{
   // Create lower form to display.
   Form bottomForm = new Form();
   // Display the lower form Maximized to demonstrate effect of TopMost property.
   bottomForm.WindowState = FormWindowState.Maximized;
   // Display the bottom form.
   bottomForm.Show();
   // Create the top most form.
   Form topMostForm = new Form();
   // Set the size of the form larger than the default size.
   topMostForm.Size = new Size(300,300);
   // Set the position of the top most form to center of screen.
   topMostForm.StartPosition = FormStartPosition.CenterScreen;
   // Display the form as top most form.
   topMostForm.TopMost = true;
   topMostForm.Show();
}

Private Sub CreateMyTopMostForm()
   ' Create lower form to display.
   Dim bottomForm As New Form()
   ' Display the lower form Maximized to demonstrate effect of TopMost property.
   bottomForm.WindowState = FormWindowState.Maximized
   ' Display the bottom form.
   bottomForm.Show()
   ' Create the top most form.
   Dim topMostForm As New Form()
   ' Set the size of the form larger than the default size.
   topMostForm.Size = New Size(300, 300)
   ' Set the position of the top most form to center of screen.
   topMostForm.StartPosition = FormStartPosition.CenterScreen
   ' Display the form as top most form.
   topMostForm.TopMost = True
   topMostForm.Show()
End Sub

注解

最顶层窗体是一种与所有其他 (非最顶端) 窗体重叠的窗体，即使它不是活动窗体或前台窗体也是如此。 最顶部的窗体始终显示在桌面上窗口 z 顺序的最高点。 可以使用此属性创建始终显示在应用程序中的窗体，例如“查找和替换”工具窗口。

另请参阅

• TopLevel