Control.KeyUp Händelse

public:
 event System::Windows::Forms::KeyEventHandler ^ KeyUp;

public event System.Windows.Forms.KeyEventHandler KeyUp;

public event System.Windows.Forms.KeyEventHandler? KeyUp;

member this.KeyUp : System.Windows.Forms.KeyEventHandler 

Public Custom Event KeyUp As KeyEventHandler 

Händelsetyp

Exempel

I följande kodexempel används KeyUp händelsen med Help klassen för att visa hjälp med popup-format för användaren.

   // 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.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 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

I följande kodexempel visas ordningen för att öka KeyDown, KeyUp och KeyPress händelser, samt hur du registrerar händelsehanterare på dem.

public partial class Form2 : Form
{
    public Form2()
    {
        InitializeComponent();
        textBox2.Multiline = true;
        textBox2.ScrollBars = ScrollBars.Both;

        //Setup events that listens on keypress
        textBox1.KeyDown += TextBox1_KeyDown;
        textBox1.KeyPress += TextBox1_KeyPress;
        textBox1.KeyUp += TextBox1_KeyUp;
    }

    // Handle the KeyUp event to print the type of character entered into the control.
    private void TextBox1_KeyUp(object sender, KeyEventArgs e)
    {
        textBox2.AppendText( $"KeyUp code: {e.KeyCode}, value: {e.KeyValue}, modifiers: {e.Modifiers}" + "\r\n");
    }

    // Handle the KeyPress event to print the type of character entered into the control.
    private void TextBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        textBox2.AppendText( $"KeyPress keychar: {e.KeyChar}" + "\r\n");
    }

    // Handle the KeyDown event to print the type of character entered into the control.
    private void TextBox1_KeyDown(object sender, KeyEventArgs e)
    {
        textBox2.AppendText( $"KeyDown code: {e.KeyCode}, value: {e.KeyValue}, modifiers: {e.Modifiers}" + "\r\n");
    }
}

Public Class Form2

    ' Handle the KeyDown event to print the type of character entered into the control.
    Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
        TextBox2.AppendText($"KeyDown code: {e.KeyCode}, value: {e.KeyValue}, modifiers: {e.Modifiers}" + vbCrLf)
    End Sub

    ' Handle the KeyPress event to print the type of character entered into the control.
    Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
        TextBox2.AppendText($"KeyPress keychar: {e.KeyChar}" + vbCrLf)
    End Sub

    ' Handle the KeyUp event to print the type of character entered into the control.
    Private Sub TextBox1_KeyUp(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyUp
        TextBox2.AppendText($"KeyUp code: {e.KeyCode}, value: {e.KeyValue}, modifiers: {e.Modifiers}" + vbCrLf)
    End Sub

End Class

Kommentarer

Viktiga händelser inträffar i följande ordning:

1. KeyDown

2. KeyPress

3. KeyUp

Om du bara vill hantera tangentbordshändelser på formulärnivå och inte aktivera andra kontroller för att ta emot tangentbordshändelser anger du KeyPressEventArgs.Handled egenskapen i formulärets KeyPress händelsehanteringsmetod till true. Vissa nycklar, till exempel TAB, RETURN, ESC och piltangenterna hanteras automatiskt av kontroller. Om du vill att dessa nycklar ska generera KeyUp händelsen måste du åsidosätta IsInputKey metoden i varje kontroll i formuläret. Koden för åsidosättningen av IsInputKey skulle behöva avgöra om någon av specialnycklarna trycks på och returnera ett värde på true.

Mer information om hur du hanterar händelser finns i Hantera och höja händelser.

Se även

• OnKeyUp(KeyEventArgs)
• KeyDown
• KeyPress