default viewer on Windows mobile 6.x

How can I find out if a default viewer exist for a file type (PDF for example)? I am planing to use ShellExecute to open a PDF file that I have downloaded from server, but I need to know if the device is capable of vie开发者_JAVA百科wing the file before I attempt to download it.

P.S. This is a Visual C++ 2008 mobile project.

Thank You Sam

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Same as with the desktop. For example, for PDFs you'd look in the registry (with RegOpenKeyEx and its relatives) for an extension association:

[HKEY_CLASSES_ROOT\.pdf]

If that exists, the default value will be the name of another key in HKEY_CLASSES_ROOT, which you'd open to

[HKEY_CLASSES_ROOT\{class name}\Shell\Open\Command which would tell you what, exactly, ShellExecute will run.