Control.OnKeyUp 方法
引发 KeyUp 事件。
**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms(在 system.windows.forms.dll 中)
语法
声明
Protected Overridable Sub OnKeyUp ( _
e As KeyEventArgs _
)
用法
Dim e As KeyEventArgs
Me.OnKeyUp(e)
protected virtual void OnKeyUp (
KeyEventArgs e
)
protected:
virtual void OnKeyUp (
KeyEventArgs^ e
)
protected void OnKeyUp (
KeyEventArgs e
)
protected function OnKeyUp (
e : KeyEventArgs
)
参数
- e
包含事件数据的 KeyEventArgs。
备注
引发事件时会通过委托调用事件处理程序。有关更多信息,请参见 引发事件。
OnKeyUp 方法还允许派生类对事件进行处理而不必附加委托。这是在派生类中处理事件的首选技术。
给继承者的说明 在派生类中重写 OnKeyUp 时,一定要调用基类的 OnKeyUp 方法,以便已注册的委托对事件进行接收。
示例
下面的代码示例使用带有 Help 类的 KeyUp 事件向用户显示弹出样式帮助。
' This example demonstrates how to use the KeyUp event with the Help class to display
' pop-up style help to the user of the application. When the user presses F1, the Help
' class displays a pop-up window, similar to a ToolTip, near the control. This example assumes
' that a TextBox control, named textBox1, has been added to the form and its KeyUp
' event has been contected to this event handler method.
Private Sub textBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles textBox1.KeyUp
' Determine whether the key entered is the F1 key. Display help if it is.
If e.KeyCode = Keys.F1 Then
' Display a pop-up help topic to assist the user.
Help.ShowPopup(textBox1, "Enter your first name", New Point(textBox1.Right, Me.textBox1.Bottom))
End If
End Sub 'textBox1_KeyUp
// This example demonstrates how to use the KeyUp event with the Help class to display
// pop-up style help to the user of the application. When the user presses F1, the Help
// class displays a pop-up window, similar to a ToolTip, near the control. This example assumes
// that a TextBox control, named textBox1, has been added to the form and its KeyUp
// event has been contected to this event handler method.
private void textBox1_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e)
{
// Determine whether the key entered is the F1 key. Display help if it is.
if(e.KeyCode == Keys.F1)
{
// Display a pop-up help topic to assist the user.
Help.ShowPopup(textBox1, "Enter your first name", new Point(textBox1.Right, this.textBox1.Bottom));
}
}
// This example demonstrates how to use the KeyUp event with the Help class to display
// pop-up style help to the user of the application. When the user presses F1, the Help
// class displays a pop-up window, similar to a ToolTip, near the control. This example assumes
// that a TextBox control, named textBox1, has been added to the form and its KeyUp
// event has been connected to this event handler method.
private:
void textBox1_KeyUp( Object^ /*sender*/, System::Windows::Forms::KeyEventArgs^ e )
{
// Determine whether the key entered is the F1 key. Display help if it is.
if ( e->KeyCode == Keys::F1 )
{
// Display a pop-up help topic to assist the user.
Help::ShowPopup( textBox1, "Enter your first name", Point(textBox1->Right,this->textBox1->Bottom) );
}
}
// This example demonstrates how to use the KeyUp event with the Help
// class to display pop-up style help to the user of the application.
// When the user presses F1, the Help class displays a pop-up window,
// similar to a ToolTip, near the control. This example assumes that a
// TextBox control, named textBox1, has been added to the form and its
// KeyUp event has been contected to this event handler method.
private void textBox1_KeyUp(Object sender,
System.Windows.Forms.KeyEventArgs e)
{
// Determine whether the key entered is the F1 key.
// Display help if it is.
if (e.get_KeyCode().Equals(Keys.F1)) {
// Display a pop-up help topic to assist the user.
Help.ShowPopup(textBox1, "Enter your first name",
new Point(textBox1.get_Right(), this.textBox1.get_Bottom()));
}
} //textBox1_KeyUp
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表,请参见系统要求。
版本信息
.NET Framework
受以下版本支持:2.0、1.1、1.0
.NET Compact Framework
受以下版本支持:2.0、1.0