ToolStripDropDown.KeyDown ToolStripDropDown.KeyDown ToolStripDropDown.KeyDown ToolStripDropDown.KeyDown Event

定义

ToolStripDropDown 具有焦点的情况下按下某个键并保持时发生。Occurs when a key is pressed and held down while the ToolStripDropDown has focus.

public:
 event System::Windows::Forms::KeyEventHandler ^ KeyDown;
[System.ComponentModel.Browsable(false)]
public event System.Windows.Forms.KeyEventHandler KeyDown;
member this.KeyDown : System.Windows.Forms.KeyEventHandler 
Public Custom Event KeyDown As KeyEventHandler 
属性

示例

下面的代码示例演示如何使用此成员。The following code example demonstrates the use of this member. 在此示例中, 事件处理程序报告KeyDown事件的发生。In the example, an event handler reports on the occurrence of the KeyDown event. 此报表可帮助你了解何时发生事件, 并可帮助你进行调试。This report helps you to learn when the event occurs and can assist you in debugging. 若要报告多个事件或频繁发生的事件, 请考虑MessageBox.ShowConsole.WriteLine消息替换为多行或将TextBox其追加到多行。To report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.

若要运行示例代码, 请将其粘贴到包含名为ToolStripDropDown ToolStripDropDown1的类型的实例的项目中。To run the example code, paste it into a project that contains an instance of type ToolStripDropDown named ToolStripDropDown1. 然后, 确保事件处理程序与KeyDown事件相关联。Then ensure that the event handler is associated with the KeyDown event.

private void ToolStripDropDown1_KeyDown(Object sender, KeyEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "Alt", e.Alt );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Control", e.Control );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Handled", e.Handled );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "KeyCode", e.KeyCode );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "KeyValue", e.KeyValue );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "KeyData", e.KeyData );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Modifiers", e.Modifiers );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Shift", e.Shift );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "SuppressKeyPress", e.SuppressKeyPress );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "KeyDown Event" );
}
Private Sub ToolStripDropDown1_KeyDown(sender as Object, e as KeyEventArgs) _ 
     Handles ToolStripDropDown1.KeyDown

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "Alt", e.Alt)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Control", e.Control)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Handled", e.Handled)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "KeyCode", e.KeyCode)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "KeyValue", e.KeyValue)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "KeyData", e.KeyData)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Modifiers", e.Modifiers)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Shift", e.Shift)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "SuppressKeyPress", e.SuppressKeyPress)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"KeyDown Event")

End Sub

注解

有关处理事件的详细信息, 请参阅处理和引发事件For more information about handling events, see Handling and Raising Events.

适用于