自定义 Directshow 过滤器的属性页

发布于 2024-10-17 08:07:28 字数 1555 浏览 2 评论 0原文

我设法创建一个自定义 DirectShow 转换过滤器，注册它，并将其导出到 DLL 中。现在它可以在 GraphEdit 和 C++ 测试程序中正常工作。我的下一个目标是创建一个自定义界面来从测试应用程序或 GraphEdit 中的属性页控制过滤器的主要参数。

按照这些说明，我得到了我的自定义接口在 C++ 测试程序中正常工作。但是，我在属性页方面遇到了困难：我在 GraphEdit 中不断收到错误消息“无法显示请求的属性页”。

在调试时，我发现调用的唯一方法（在我的自定义属性页类中，从 CBasePropertyPage 派生）是 OnConnect() 和 OnDisconnect() - 这很奇怪（或不是吗？）打了两次电话。在这两个方法之间，对 CBasePropertyPage 方法进行了一些调用（基类中的文件 cprop.cpp），一切看起来都很好，直到：

STDMETHODIMP CBasePropertyPage::Activate(HWND hwndParent, LPCRECT pRect, BOOL fModal)

和更准确地说，

m_hwnd = CreateDialogParam(g_hInst, MAKEINTRESOURCE(m_DialogId), hwndParent, DialogProc, (LPARAM) this);

我总是得到 m_hwnd 为 0，导致该方法返回一个错误。我尝试在这条指令之后添加 GetLastError() ，但它总是返回 0，没有错误。此外，CreateDialogParam() 的每个参数看起来都已正确初始化...

任何帮助将不胜感激！

编辑：

目前，为了至少有一个工作示例，我使用了 MSDN 教程。

---编辑2---：

在进行更多调试时，我尝试从对话框资源中删除每个控件（按钮、滚动条）。之后......一切正常。 CreateDialogParam() 返回正确的值，调用我的类的 OnActivate() 等等。我最终在 GraphEdit 中得到一个“过滤器属性”页面，但它是空的（默认对话框窗口除外）。

但是一旦我有了一个控件，例如MF命令按钮，前面的问题就出现了。

DirectShow 基类和我使用的控件之间是否存在任何类型的不兼容？（如果是这样，为什么提供的示例没有提及任何内容？）是否有更简单的方法将控件添加到属性页？

（我绝对不是 GUI 和 Win32 控件方面的专家...）

原文

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.

Following these instructions, 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.

While debugging, I found that the only methods called (in my custom property page class, derived from CBasePropertyPage) are OnConnect() and OnDisconnect() - 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 :

STDMETHODIMP CBasePropertyPage::Activate(HWND hwndParent, LPCRECT pRect, BOOL fModal)

and more precisely

m_hwnd = CreateDialogParam(g_hInst, MAKEINTRESOURCE(m_DialogId), hwndParent, DialogProc, (LPARAM) this);

I always get m_hwnd at 0, causing the method to return with an error. I tried to add GetLastError() right after this instruction, but it always returns 0, no error. Moreover, every parameter of CreateDialogParam() looks properly initialized...

Any help would be greatly appreciated !

EDIT :

For now, in order to at least have a working example, I've used the same resources/templates described in the MSDN tutorial.

---EDIT 2--- :

While debugging a little bit more, I tried deleting every single control (button, scroller) from the Dialog resource. After that... everything works. CreateDialogParam() returns a correct value, my class's OnActivate() is called and so on. I eventually get a "filter properties" page in GraphEdit, but empty (except from the default dialog window).

But as soon as I had a control, e.g. a MF command button, the previous problems appear.

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 ?

(I'm definitely not an expert with GUIs and Win32 controls...)

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