Assembly: System (in system.dll)
The MainWindowHandle is not defined because the process has exited.
You are trying to access the MainWindowHandle property for a process that is running on a remote computer. This property is available only for processes that are running on the local computer.
The platform is Windows 98 or Windows Millennium Edition (Windows Me); set ProcessStartInfo.UseShellExecute to false to access this property on Windows 98 and Windows Me.
The main window is the window that is created when the process is started. After initialization, other windows may be opened, including the Modal and TopLevel windows, but the first window associated with the process remains the main window.
You can get the MainWindowHandle property only for processes that are running on the local computer. The MainWindowHandle property is a value that uniquely identifies the window that is associated with the process.
A process has a main window associated with it only if the process has a graphical interface. If the associated process does not have a main window, the MainWindowHandle value is zero. If you have just started a process and want to use its main window handle, consider using the WaitForInputIdle method to allow the process to finish starting, ensuring that the main window handle has been created. Otherwise, an exception will be thrown.
Windows 98, Windows Millennium Edition Platform Note: This property is not available on this platform if you started the process with ProcessStartInfo.UseShellExecute set to true.
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter EditionThe Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.