How to get the clipboard content in WPF

You need to use this: http://msdn.microsoft.com/en-us/library/system.windows.clipboard.aspx[^].

The method you want is GetData or GetDataObject.

Probably, your problem is working with the custom data format. In this clipboard class, this functionality is predefined via the special data format expressed by means of the class DataFormats and its public field DataFormats.Serializable:
http://msdn.microsoft.com/en-us/library/system.windows.dataformats.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.dataformats.serializable.aspx[^].

The use of this format is based on the assumption of using the class DataObject implementing the interface IDataObject:
http://msdn.microsoft.com/en-us/library/system.windows.dataobject.aspx[^],
http://msdn.microsoft.com/en-us/library/system.windows.idataobject.aspx[^].

The background of it is pretty simple and interesting. As the low-level of the Clipboard is some serialized raw byte data (how else? Clipboard is system-wide), the mechanism is based on serialization:
http://en.wikipedia.org/wiki/Serialization[^],
http://en.wikipedia.org/wiki/Serialization#.NET_Framework[^].
http://msdn.microsoft.com/en-us/library/vstudio/ms233843.aspx[^].

Custom Clipboard types are registered with some string atom, unique in the scope of system which should be recognized by the code putting data in Clipboard and reading it. It's enough that both parts used identical serialization mechanism, not matter what kind. As soon as those to parts of code share the same mechanism, everything works; and for the applications not involved in using this custom type, this is some unrecognized format they are not subscribed to.

—SA