KeyEventArgs Klasse

Definition

Stellt Daten für das KeyDown-Ereignis oder das KeyUp-Ereignis bereit.Provides data for the KeyDown or KeyUp event.

public ref class KeyEventArgs : EventArgs
[System.Runtime.InteropServices.ComVisible(true)]
public class KeyEventArgs : EventArgs
type KeyEventArgs = class
    inherit EventArgs
Public Class KeyEventArgs
Inherits EventArgs
Vererbung
KeyEventArgs
Attribute

Beispiele

Die folgenden Codebeispiele veranschaulichen, wie Sie den Zustand eines Tastendruck erkennen.The following code examples demonstrate how to detect the state of a key press.

Beispiel 1Example 1

Im folgenden Codebeispiel wird veranschaulicht, wie das KeyDown -Ereignis mit Help der-Klasse verwendet wird, um dem Benutzer der Anwendung Popup-Stil-Hilfe anzuzeigen.The following code example demonstrates how to use the KeyDown event with the Help class to display pop-up style Help to the user of the application. Das Beispiel verwendet die KeyEventArgs Eigenschaften, die an die Ereignishandlermethode übermittelt werden, um nach allen Variationen der Tastenkombination mit einer Modifizierertaste zu filtern.The example uses the KeyEventArgs properties passed to the event handler method to filter for all variations of pressing the F1 key with a modifier key. Wenn der Benutzer eine beliebige Variation von F1 drückt, die einen beliebigen Tastatur Modifizierer enthält, zeigt die Help -Klasse ein Popup Fenster an, das ähnlich wie ein ToolTip-Steuerelement in der Nähe des Steuer Elements ist.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. Wenn der Benutzer ALT + F2 drückt, wird ein anderes Popup Fenster mit zusätzlichen Informationen angezeigt.If the user presses ALT+F2, a different Help pop-up is displayed with additional information.

   // 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) );
      }
   }
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

Beispiel 2Example 2

Im folgenden Beispiel wird ermittelt, ob der Benutzer ALT + E gedrückt hat, und wenn sich der Maus TreeNodeZeiger über einem befindet, kann der TreeNodeBenutzer das Bearbeiten.The following example determines whether the user pressed ALT+E, and if the mouse pointer is over a TreeNode, allows the user to edit that TreeNode.

private:
   void treeView1_KeyDown( Object^ /*sender*/, KeyEventArgs^ e )
   {
      /* If the 'Alt' and 'E' keys are pressed,
         * allow the user to edit the TreeNode label. */
      if ( e->Alt && e->KeyCode == Keys::E )
      {
         treeView1->LabelEdit = true;
         
         // If there is a TreeNode under the mose cursor, begin editing.
         TreeNode^ editNode = treeView1->GetNodeAt( treeView1->PointToClient( Control::MousePosition ) );
         if ( editNode != nullptr )
         {
            editNode->BeginEdit();
         }
      }
   }

   void treeView1_AfterLabelEdit( Object^ /*sender*/, NodeLabelEditEventArgs^ /*e*/ )
   {
      // Disable the ability to edit the TreeNode labels.
      treeView1->LabelEdit = false;
   }
private void treeView1_KeyDown(object sender, KeyEventArgs e)
{
   /* If the 'Alt' and 'E' keys are pressed,
      * allow the user to edit the TreeNode label. */
   if(e.Alt && e.KeyCode == Keys.E)
         
   {
      treeView1.LabelEdit = true;
      // If there is a TreeNode under the mose cursor, begin editing. 
      TreeNode editNode = treeView1.GetNodeAt(
         treeView1.PointToClient(System.Windows.Forms.Control.MousePosition));
      if(editNode != null)
      { 
         editNode.BeginEdit();
      }
   }
}

private void treeView1_AfterLabelEdit(object sender, NodeLabelEditEventArgs e)
{
   // Disable the ability to edit the TreeNode labels.
   treeView1.LabelEdit = false;
}
Private Sub treeView1_KeyDown(sender As Object, _
  e As KeyEventArgs) Handles treeView1.KeyDown
   ' If the 'Alt' and 'E' keys are pressed,
   ' allow the user to edit the TreeNode label. 
   If e.Alt And e.KeyCode = Keys.E Then
      treeView1.LabelEdit = True
      ' If there is a TreeNode under the mose cursor, begin editing. 
      Dim editNode As TreeNode = treeView1.GetNodeAt( _
        treeView1.PointToClient(System.Windows.Forms.Control.MousePosition))
      If (editNode IsNot Nothing) Then
         editNode.BeginEdit()
      End If
   End If
End Sub

Private Sub treeView1_AfterLabelEdit(sender As Object, _
  e As NodeLabelEditEventArgs) Handles treeView1.AfterLabelEdit
   ' Disable the ability to edit the TreeNode labels.
   treeView1.LabelEdit = False
End Sub

Beispiel 3Example 3

Im folgenden Beispiel wird ermittelt, ob der Benutzer einen nicht numerischen Schlüssel gedrückt hat, und wenn dies der Fall KeyPress ist, wird das Handled Ereignis mit der-Eigenschaft abgebrochen.The following example determines whether the user pressed a non-numeric key, and if so, cancels the KeyPress event by using the Handled property.

   // Boolean flag used to determine when a character other than a number is entered.
private:
   bool nonNumberEntered;

   // Handle the KeyDown event to determine the type of character entered into the control.
   void textBox1_KeyDown( Object^ /*sender*/, System::Windows::Forms::KeyEventArgs^ e )
   {
      // Initialize the flag to false.
      nonNumberEntered = false;

      // Determine whether the keystroke is a number from the top of the keyboard.
      if ( e->KeyCode < Keys::D0 || e->KeyCode > Keys::D9 )
      {
         // Determine whether the keystroke is a number from the keypad.
         if ( e->KeyCode < Keys::NumPad0 || e->KeyCode > Keys::NumPad9 )
         {
            // Determine whether the keystroke is a backspace.
            if ( e->KeyCode != Keys::Back )
            {
               // A non-numerical keystroke was pressed.
               // Set the flag to true and evaluate in KeyPress event.
               nonNumberEntered = true;
            }
         }
      }
      //If shift key was pressed, it's not a number.
      if (Control::ModifierKeys == Keys::Shift) {
         nonNumberEntered = true;
      }
   }

   // This event occurs after the KeyDown event and can be used to prevent
   // characters from entering the control.
   void textBox1_KeyPress( Object^ /*sender*/, System::Windows::Forms::KeyPressEventArgs^ e )
   {
      // Check for the flag being set in the KeyDown event.
      if ( nonNumberEntered == true )
      {         // Stop the character from being entered into the control since it is non-numerical.
         e->Handled = true;
      }
   }
// Boolean flag used to determine when a character other than a number is entered.
private bool nonNumberEntered = false;

// Handle the KeyDown event to determine the type of character entered into the control.
private void textBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
    // Initialize the flag to false.
    nonNumberEntered = false;

    // Determine whether the keystroke is a number from the top of the keyboard.
    if (e.KeyCode < Keys.D0 || e.KeyCode > Keys.D9)
    {
        // Determine whether the keystroke is a number from the keypad.
        if (e.KeyCode < Keys.NumPad0 || e.KeyCode > Keys.NumPad9)
        {
            // Determine whether the keystroke is a backspace.
            if(e.KeyCode != Keys.Back)
            {
                // A non-numerical keystroke was pressed.
                // Set the flag to true and evaluate in KeyPress event.
                nonNumberEntered = true;
            }
        }
    }
    //If shift key was pressed, it's not a number.
    if (Control.ModifierKeys == Keys.Shift) {
        nonNumberEntered = true;
    }
}

// This event occurs after the KeyDown event and can be used to prevent
// characters from entering the control.
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
    // Check for the flag being set in the KeyDown event.
    if (nonNumberEntered == true)
    {
        // Stop the character from being entered into the control since it is non-numerical.
        e.Handled = true;
    }
}

 ' Boolean flag used to determine when a character other than a number is entered.
 Private nonNumberEntered As Boolean = False


 ' Handle the KeyDown event to determine the type of character entered into the control.
 Private Sub textBox1_KeyDown(sender As Object, e As System.Windows.Forms.KeyEventArgs) _
      Handles textBox1.KeyDown
     ' Initialize the flag to false.
     nonNumberEntered = False
   
     ' Determine whether the keystroke is a number from the top of the keyboard.
     If e.KeyCode < Keys.D0 OrElse e.KeyCode > Keys.D9 Then
         ' Determine whether the keystroke is a number from the keypad.
         If e.KeyCode < Keys.NumPad0 OrElse e.KeyCode > Keys.NumPad9 Then
             ' Determine whether the keystroke is a backspace.
             If e.KeyCode <> Keys.Back Then
                 ' A non-numerical keystroke was pressed. 
                 ' Set the flag to true and evaluate in KeyPress event.
                 nonNumberEntered = True
             End If
         End If
     End If
     'If shift key was pressed, it's not a number.
     If Control.ModifierKeys = Keys.Shift Then
         nonNumberEntered = true
     End If
 End Sub


 ' This event occurs after the KeyDown event and can be used 
 ' to prevent characters from entering the control.
 Private Sub textBox1_KeyPress(sender As Object, e As System.Windows.Forms.KeyPressEventArgs) _
     Handles textBox1.KeyPress
     ' Check for the flag being set in the KeyDown event.
     If nonNumberEntered = True Then
         ' Stop the character from being entered into the control since it is non-numerical.
         e.Handled = True
     End If
 End Sub

Hinweise

Ein KeyEventArgs, der die vom Benutzer gedrückte Taste angibt und angibt, ob alle Modifizierertasten (STRG, alt und UMSCHALT) gleichzeitig gedrückt wurden, und wird mit KeyDown jedem KeyUp -Ereignis oder einem-Ereignis übermittelt.A KeyEventArgs, which specifies the key the user pressed and whether any modifier keys (CTRL, ALT, and SHIFT) were pressed at the same time, is passed with each KeyDown or KeyUp event.

Das KeyDown Ereignis tritt auf, wenn der Benutzer eine Taste drückt.The KeyDown event occurs when the user presses any key. Das KeyUp Ereignis tritt auf, wenn der Benutzer den Schlüssel freigibt.The KeyUp event occurs when the user releases the key. Doppelte KeyDown Ereignisse treten immer dann auf, wenn der Schlüssel wiederholt wird, wenn der Schlüssel nicht mehr KeyUp vorhanden ist, aber nur ein Ereignis generiert wird, wenn der Benutzer den Schlüssel freigibt.Duplicate KeyDown events occur each time the key repeats, if the key is held down, but only one KeyUp event is generated when the user releases the key.

Das KeyPress Ereignis tritt auch auf, wenn eine Taste gedrückt wird.The KeyPress event also occurs when a key is pressed. Eine KeyPressEventArgs wird mit jedem KeyPress Ereignis weitergegeben und gibt das Zeichen an, das als Ergebnis der einzelnen Tastenkombination erstellt wurde.A KeyPressEventArgs is passed with each KeyPress event, and specifies the character that was composed as a result of each key press.

Weitere Informationen zum Ereignis Modell finden Sie unter behandeln und Auswerfen von Ereignissen.For information about the event model, see Handling and Raising Events.

Konstruktoren

KeyEventArgs(Keys)

Initialisiert eine neue Instanz der KeyEventArgs-Klasse.Initializes a new instance of the KeyEventArgs class.

Eigenschaften

Alt

Ruft einen Wert ab, der angibt, ob ALT gedrückt wurde.Gets a value indicating whether the ALT key was pressed.

Control

Ruft einen Wert ab, der angibt, ob STRG gedrückt wurde.Gets a value indicating whether the CTRL key was pressed.

Handled

Ruft einen Wert ab, der angibt, ob das Ereignis behandelt wurde, oder legt diesen fest.Gets or sets a value indicating whether the event was handled.

KeyCode

Ruft den Tastaturcode für ein KeyDown-Ereignis oder ein KeyUp-Ereignis ab.Gets the keyboard code for a KeyDown or KeyUp event.

KeyData

Ruft die Tastendaten für ein KeyDown-Ereignis oder ein KeyUp-Ereignis ab.Gets the key data for a KeyDown or KeyUp event.

KeyValue

Ruft den Tastaturwert für ein KeyDown-Ereignis oder ein KeyUp-Ereignis ab.Gets the keyboard value for a KeyDown or KeyUp event.

Modifiers

Ruft die Modifiziererflags für ein KeyDown-Ereignis oder ein KeyUp-Ereignis ab.Gets the modifier flags for a KeyDown or KeyUp event. Die Flags geben an, welche Kombination aus STRG, UMSCHALTTASTE und ALT gedrückt wurde.The flags indicate which combination of CTRL, SHIFT, and ALT keys was pressed.

Shift

Ruft einen Wert ab, der angibt, ob die UMSCHALTTASTE gedrückt wurde.Gets a value indicating whether the SHIFT key was pressed.

SuppressKeyPress

Ruft einen Wert ab, der angibt, ob das Key-Ereignis an das zugrunde liegende Steuerelement übergeben werden soll.Gets or sets a value indicating whether the key event should be passed on to the underlying control.

Methoden

Equals(Object)

Bestimmt, ob das angegebene Objekt mit dem aktuellen Objekt identisch ist.Determines whether the specified object is equal to the current object.

(Geerbt von Object)
GetHashCode()

Fungiert als Standardhashfunktion.Serves as the default hash function.

(Geerbt von Object)
GetType()

Ruft den Type der aktuellen Instanz ab.Gets the Type of the current instance.

(Geerbt von Object)
MemberwiseClone()

Erstellt eine flache Kopie des aktuellen Object.Creates a shallow copy of the current Object.

(Geerbt von Object)
ToString()

Gibt eine Zeichenfolge zurück, die das aktuelle Objekt darstellt.Returns a string that represents the current object.

(Geerbt von Object)

Gilt für:

Siehe auch