Control.KeyUp Gebeurtenis
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Treedt op wanneer een sleutel wordt vrijgegeven terwijl het besturingselement de focus heeft.
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
Gebeurtenistype
Voorbeelden
In het volgende codevoorbeeld wordt de KeyUp gebeurtenis met de Help klasse gebruikt om pop-upstijl weer te geven aan de gebruiker.
// 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
In het volgende codevoorbeeld ziet u de volgorde waarin de KeyDowngebeurtenis-handlers KeyUp worden geregistreerd en KeyPress gebeurtenissen.
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
Opmerkingen
Belangrijke gebeurtenissen vinden plaats in de volgende volgorde:
Als u toetsenbordgebeurtenissen alleen op formulierniveau wilt afhandelen en andere besturingselementen niet wilt inschakelen voor het ontvangen van toetsenbordgebeurtenissen, stelt u de KeyPressEventArgs.Handled eigenschap in de methode voor gebeurtenisafhandeling van het formulier KeyPress in op true. Bepaalde toetsen, zoals tab, RETURN, ESC en pijltoetsen, worden automatisch verwerkt door besturingselementen. Als u deze sleutels de KeyUp gebeurtenis wilt laten genereren, moet u de IsInputKey methode in elk besturingselement in uw formulier overschrijven. De code voor de onderdrukking van IsInputKey moet bepalen of een van de speciale toetsen wordt ingedrukt en een waarde van true.
Zie Gebeurtenissen verwerken en genereren voor meer informatie over het afhandelen van gebeurtenissen.