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POProperty page for custom Directshow filter
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copied!<p>I managed to create a custom DirectShow transform filter, register it, and export it in a DLL. It now works properly in both GraphEdit and a C++ test program. My next goal is to create a custom interface to control the filter's main parameter, from a test app or from a property page in GraphEdit.</p> <p>Following <a href="http://msdn.microsoft.com/en-us/library/dd375010%28v=VS.85%29.aspx" rel="nofollow">these instructions</a>, I got my custom interface working properly from the C++ test program. However, I'm facing difficulties with the property page : I keep getting the error message "The requested property page could not be displayed" in GraphEdit.</p> <p>While debugging, I found that the only methods called (in my custom property page class, derived from CBasePropertyPage) are <code>OnConnect()</code> and <code>OnDisconnect()</code> - which is oddly (or not ?) called twice. Between these two methods, some calls are made to CBasePropertyPage methods (file cprop.cpp in baseclasses), and everything looks fine until :</p> <p><code>STDMETHODIMP CBasePropertyPage::Activate(HWND hwndParent, LPCRECT pRect, BOOL fModal)</code></p> <p>and more precisely</p> <p><code>m_hwnd = CreateDialogParam(g_hInst, MAKEINTRESOURCE(m_DialogId), hwndParent, DialogProc, (LPARAM) this);</code></p> <p>I always get <code>m_hwnd</code> at 0, causing the method to return with an error. I tried to add <code>GetLastError()</code> right after this instruction, but it always returns 0, no error. Moreover, every parameter of <code>CreateDialogParam()</code> looks properly initialized...</p> <p>Any help would be greatly appreciated !</p> <p><br/> <strong>EDIT</strong> :</p> <p>For now, in order to at least have a working example, I've used the <em>same</em> resources/templates described in the <a href="http://msdn.microsoft.com/en-us/library/dd375010%28v=VS.85%29.aspx" rel="nofollow">MSDN tutorial</a>.</p> <p><br/> <strong>---EDIT 2---</strong> :</p> <p>While debugging a little bit more, I tried deleting every single control (button, scroller) from the Dialog resource. After that... everything works. <code>CreateDialogParam()</code> returns a correct value, my class's <code>OnActivate()</code> is called and so on. I eventually get a "filter properties" page in GraphEdit, but empty (except from the default dialog window).</p> <p>But as soon as I had a control, e.g. a MF command button, the previous problems appear.</p> <p>Is there any kind of incompatibility between DirectShow base classes and the controls I use ? (And if so, why isn't the provided sample mentioning anything ?) Is there any simpler way to add controls to the property page ?</p> <p>(I'm definitely <em>not</em> an expert with GUIs and Win32 controls...)</p>

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