Occurs when the control receives focus.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
When you change the focus by using the keyboard (TAB, SHIFT+TAB, and so on), by calling the Select or SelectNextControl methods, or by setting the ContainerControl.ActiveControl property to the current form, focus events occur in the following order:
When you change the focus by using the mouse or by calling the Focus method, focus events occur in the following order:
Note The and LostFocus events are low-level focus events that are tied to the WM_KILLFOCUS and WM_SETFOCUS Windows messages. Typically, the and LostFocus events are only used when updating UICues or when writing custom controls. Instead the Enter and Leave events should be used for all controls except the Form class, which uses the Activated and Deactivate events. For more information about the and LostFocus events, see the WM_SETFOCUS and WM_KILLFOCUS topics in the "Keyboard Input Reference" section in the MSDN library at http://msdn.microsoft.com/library.
Do not attempt to set focus from within the Enter, , Leave, LostFocus, Validating, or Validated event handlers. Doing so can cause your application or the operating system to stop responding. For more information, see the WM_KILLFOCUS topic in the "Keyboard Input Reference" section, and the "Message Deadlocks" section of the "About Messages and Message Queues" topic in the MSDN library at http://msdn.microsoft.com/library.
For more information about handling events, see Consuming Events.
The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the event. This report helps you to learn when the event occurs and can assist you in debugging.
To run the example code, paste it into a project that contains an instance of a type that inherits from Control, such as a Button or ComboBox. Then name the instance Control1 and ensure that the event handler is associated with the event.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.