Useful new MessageWindow feature

Earlier in the Beta for Visual Studio 2005 I submitted a product suggestion to support a very common scenario with the MessageWindow control, and I was delighted to find that in the July CTP it has been implemented.

The MessageWindow class is provided as a mechanism to receive incoming windows messages and has become a key part of the .NETCF developers interoperability toolbox. .NETCF v2.0 extends the options we have available with new functionality such as support for passing callback functions into native code and COM interop. However there are still times when we will need the humble MessageWindow. One of the first tasks with using the MessageWindow is how to tell the sender where to send the messages. In some cases this involves passing the handle (HWND) of the MessageWindow in via a P/Invoke call, the other common way to identify a MessageWindow is by setting the text and using FindWindow.

This neatly brings me back to the new feature in question. In v1.0 you had to override the WndProc and add your own handler for WM_GETTEXT (and optionally WM_SETTEXT) in order for your MessageWindow to have a caption. .NETCF v2.0 adds the Text property making life that little bit easier. Just set the Text property to something uniquely identifiable for your application, then you can use FindWindow from your native code to get the handle (HWND) of the MessageWindow and start sending messages to it.

By Peter Foot

Microsoft Windows Development MVP