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Control.OnEnter Method

Raises the Enter event.

[Visual Basic]
Protected Overridable Sub OnEnter( _
   ByVal e As EventArgs _
)
[C#]
protected virtual void OnEnter(
 EventArgs e
);
[C++]
protected: virtual void OnEnter(
 EventArgs* e
);
[JScript]
protected function OnEnter(
   e : EventArgs
);

Parameters

e
An EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The OnEnter method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors:  When overriding OnEnter in a derived class, be sure to call the base class's OnEnter method so that registered delegates receive the event.

Example

[Visual Basic] 
Private Sub textBox1_Enter(sender As Object, e As System.EventArgs) Handles textBox1.Enter
    ' If the TextBox contains text, change its foreground and background colors.
    If textBox1.Text <> [String].Empty Then
        textBox1.ForeColor = Color.Red
        textBox1.BackColor = Color.Black
        ' Move the selection pointer to the end of the text of the control.
        textBox1.Select(textBox1.Text.Length, 0)
    End If
End Sub 'textBox1_Enter
   
   
Private Sub textBox1_Leave(sender As Object, e As System.EventArgs) Handles textBox1.Leave
    ' Reset the colors and selection of the TextBox after focus is lost.
    textBox1.ForeColor = Color.Black
    textBox1.BackColor = Color.White
    textBox1.Select(0, 0)
End Sub 'textBox1_Leave
End Class 'Form1 

[C#] 
private void textBox1_Enter(object sender, System.EventArgs e)
{
    // If the TextBox contains text, change its foreground and background colors.
    if (textBox1.Text != String.Empty)
    {
        textBox1.ForeColor = Color.Red;
        textBox1.BackColor = Color.Black;
        // Move the selection pointer to the end of the text of the control.
        textBox1.Select(textBox1.Text.Length, 0);
    }
}

private void textBox1_Leave(object sender, System.EventArgs e)
{
    // Reset the colors and selection of the TextBox after focus is lost.
    textBox1.ForeColor = Color.Black;
    textBox1.BackColor = Color.White;
    textBox1.Select(0,0);
}

[C++] 
private:
   void textBox1_Enter(Object* /*sender*/, System::EventArgs* /*e*/)
   {
      // If the TextBox contains text, change its foreground and background colors.
      if (textBox1->Text != String::Empty)
      {
         textBox1->ForeColor = Color::Red;
         textBox1->BackColor = Color::Black;
         // Move the selection pointer to the end of the text of the control.
         textBox1->Select(textBox1->Text->Length, 0);
      }
   }

   void textBox1_Leave(Object* /*sender*/, System::EventArgs* /*e*/)
   {
      // Reset the colors and selection of the TextBox after focus is lost.
      textBox1->ForeColor = Color::Black;
      textBox1->BackColor = Color::White;
      textBox1->Select(0,0);
   }

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

Control Class | Control Members | System.Windows.Forms Namespace | Enter

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