Control.OnKeyPress(KeyPressEventArgs) Control.OnKeyPress(KeyPressEventArgs) Control.OnKeyPress(KeyPressEventArgs) Control.OnKeyPress(KeyPressEventArgs) Method

정의

KeyPress 이벤트를 발생시킵니다.Raises the KeyPress event.

protected:
 virtual void OnKeyPress(System::Windows::Forms::KeyPressEventArgs ^ e);
protected virtual void OnKeyPress (System.Windows.Forms.KeyPressEventArgs e);
abstract member OnKeyPress : System.Windows.Forms.KeyPressEventArgs -> unit
override this.OnKeyPress : System.Windows.Forms.KeyPressEventArgs -> unit
Protected Overridable Sub OnKeyPress (e As KeyPressEventArgs)

매개 변수

e
KeyPressEventArgs KeyPressEventArgs KeyPressEventArgs KeyPressEventArgs

이벤트 데이터를 포함하는 KeyPressEventArgs입니다.A KeyPressEventArgs that contains the event data.

예제

다음 코드 예제에서는 KeyPress 이벤트 문자로 컨트롤에 진입 하지 못하도록 합니다.The following code example uses the KeyPress event to prevent characters from entering the control.

   // 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

설명

이벤트가 발생하면 대리자를 통해 이벤트 처리기가 호출됩니다.Raising an event invokes the event handler through a delegate. 자세한 내용은 이벤트 처리 및 발생합니다.For more information, see Handling and Raising Events.

또한 OnKeyPress 메서드를 사용하면 파생 클래스가 대리자를 연결하지 않고도 이벤트를 처리할 수 있습니다.The OnKeyPress method also allows derived classes to handle the event without attaching a delegate. 이는 파생 클래스에서 이벤트를 처리하는 기본 방법입니다.This is the preferred technique for handling the event in a derived class.

상속자 참고

파생 클래스에서 OnKeyPress(KeyPressEventArgs)를 재정의하는 경우 등록된 대리자가 이벤트를 받도록 기본 클래스의 OnKeyPress(KeyPressEventArgs) 메서드를 호출해야 합니다.When overriding OnKeyPress(KeyPressEventArgs) in a derived class, be sure to call the base class's OnKeyPress(KeyPressEventArgs) method so that registered delegates receive the event.

적용 대상

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