[問題描述]
用VS2008編譯windows shell時,成功；相同的方法在VS2005和vs2003下，提示錯誤：
error C2787: 'IContextMenu' : no GUID has been associated with this object
error C2440: 'initializing' : cannot convert from 'DWORD_PTR' to 'const IID *'
error C2440: 'initializing' : cannot convert from 'ATL::_ATL_CREATORARGFUNC (__stdcall *)' to 'DWORD_PTR'
[解決方法]
關鍵的問題是以下頭文件沒有包含正確
#include "shlobj.h"
#include "comdef.h"
#include <shlguid.h>
下面是收集的一些問題解決過程：
1、Have you downloaded the Latest Platfrom SDK? If so, are your vc dirs pointing to the proper include dirs, eg: shlguid.h is getting picked up from the SDK\include and not the vc98\include. You set those in the tools-Options->directories->include dirs for VC
2、There are two <comdef.h> header files in VC.NET, one in Vc7/include and the other in Vc7/PlatformSDK/include. The former splits off the smart pointer typedefs into comdefsp.h, and it doesn't include IContextMenu. The latter does. You can try to #include the PlatformSDK header directly, change your INCLUDE path order, or supply the missing typedef yourself, e.g.
struct __declspec(uuid("000214e4-0000-0000-c000-000000000046"))
IContextMenu;
_COM_SMARTPTR_TYPEDEF(IContextMenu, __uuidof(IContextMenu));
3、怎樣找到Interface的GUID?
我在註冊表 HKCR\Interface\ 下可以找到形式爲
{aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee}的鍵，如果其下有默認項="Interface",則說明這個鍵就是該Interface的GUID。
有沒有其它方法？
(1) VC6\common\Tools 下有個OLE/COM Object Viewer 很方便，但在VC2005下就沒找到這個工具
(2) PlatformSDK\include\comdef.h 中也有GUID的定義
4、__uuidof它是C++ 運算符
如上所述，如果把PlatformSDK/include放在前面仍然不可以的話，就下載新的SDK，把include目錄包含進去就好了。個人感覺手動添加這些uuid值如，struct __declspec(uuid("000214e4-0000-0000-c000-000000000046"))
IContextMenu;
_COM_SMARTPTR_TYPEDEF(IContextMenu, __uuidof(IContextMenu));
總結：
我採用的是將vc71/PlatformSDK/include放在前面放到vc71/include的前面解決的
