Occurs when changes occur that affect whether or not the command should execute.
event EventHandler CanExecuteChanged
Normally, a command source calls CanExecute on the command when this event occurs.
Normally, if the command cannot execute, the command source disables itself.
Supported in: 4, 3.5, 3.0
.NET Framework Client Profile
Supported in: 4, 3.5 SP1
Windows 7, Windows Vista SP1 or later, Windows XP SP3, 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.