KeyEventArgs.Control 属性
重要
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获取一个值，该值指示是否曾按下 Ctrl 键。
public:
property bool Control { bool get(); };C#
public bool Control { get; }member this.Control : boolPublic ReadOnly Property Control As Boolean如果曾按下 Ctrl 键，则为 true；否则为 false。
下面的代码示例演示如何将 事件与 类一 KeyDown 起使用 Help ，以便向应用程序的用户显示弹出样式的“帮助”。 该示例使用 KeyEventArgs 传递给事件处理程序方法的属性来筛选使用修饰键按 F1 键的所有变体。 当用户按下包含任何键盘修饰符的任何 F1 变体时，类会在 Help 控件附近显示一个 ToolTip弹出窗口，类似于 。 如果用户按 Alt+F2，将显示一个不同的“帮助”弹出窗口，其中包含其他信息。
// This example demonstrates how to use the KeyDown event with the Help class to display
// pop-up style help to the user of the application. The example filters for all variations
// of pressing the F1 key with a modifier key by using the KeyEventArgs properties passed
// to the event handling method.
// When the user presses any variation of F1 that includes any keyboard modifier, the Help
// class displays a pop-up window, similar to a ToolTip, near the control. If the user presses
// ALT + F2, a different Help pop-up is displayed with additional information. This example assumes
// that a tTextBox control, named textBox1, has been added to the form and its KeyDown
// event has been contected to this event handling method.
private:
void textBox1_KeyDown( Object^ /*sender*/, System::Windows::Forms::KeyEventArgs^ e )
{
// Determine whether the key entered is the F1 key. If it is, display Help.
if ( e->KeyCode == Keys::F1 && (e->Alt || e->Control || e->Shift) )
{
// Display a pop-up Help topic to assist the user.
Help::ShowPopup( textBox1, "Enter your name.", Point(textBox1->Bottom,textBox1->Right) );
}
else
if ( e->KeyCode == Keys::F2 && e->Modifiers == Keys::Alt )
{
// Display a pop-up Help topic to provide additional assistance to the user.
Help::ShowPopup( textBox1, "Enter your first name followed by your last name. Middle name is optional.",
Point(textBox1->Top,this->textBox1->Left) );
}
}
C#
private void textBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
// Determine whether the key entered is the F1 key. If it is, display Help.
if(e.KeyCode == Keys.F1 && (e.Alt || e.Control || e.Shift))
{
// Display a pop-up Help topic to assist the user.
Help.ShowPopup(textBox1, "Enter your name.", new Point(textBox1.Bottom, textBox1.Right));
}
else if(e.KeyCode == Keys.F2 && e.Modifiers == Keys.Alt)
{
// Display a pop-up Help topic to provide additional assistance to the user.
Help.ShowPopup(textBox1, "Enter your first name followed by your last name. Middle name is optional.",
new Point(textBox1.Top, this.textBox1.Left));
}
}
Private Sub textBox1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles textBox1.KeyDown
' Determine whether the key entered is the F1 key. If it is, display Help.
If e.KeyCode = Keys.F1 AndAlso (e.Alt OrElse e.Control OrElse e.Shift) Then
' Display a pop-up Help topic to assist the user.
Help.ShowPopup(textBox1, "Enter your name.", New Point(textBox1.Bottom, textBox1.Right))
ElseIf e.KeyCode = Keys.F2 AndAlso e.Modifiers = Keys.Alt Then
' Display a pop-up Help topic to provide additional assistance to the user.
Help.ShowPopup(textBox1, "Enter your first name followed by your last name. Middle name is optional.", _
New Point(textBox1.Top, Me.textBox1.Left))
End If
End Sub
| 产品 | 版本 |
|---|---|
| .NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
| Windows Desktop | 3.0, 3.1, 5, 6, 7, 8, 9 |
