Control::OnEnter Method
Raises the Enter event.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
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 InheritorsWhen overriding OnEnter in a derived class, be sure to call the base class's OnEnter method so that registered delegates receive the event.
The following code example uses the Enter event to change the foreground and background colors of a TextBox under particular conditions.
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); }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.