This new feature, which isn’t limited to Windows Forms, allows a single class to extend across multiple files, isn’t limited to Windows Forms but the designer-generated code is just screaming out for a solution like this.

Jay writes:

Winforms designed code and C# partial classes

_In Whidbey, the WinForms designer takes advantage of a new C# language feature called “_ [ _partial classes_ ](http://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=C%23+partial+classes) _”. This allows them to pull out the designer generated code into a separate file. It has several advantages...
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