如何調試COM DLL
在“解決方案資源管理器”中，右擊組件項目并單擊快捷菜單上的“屬性”。<項目名稱>“屬性頁”對話框中，打開“配置屬性”文件夾并選定“調試”類別。在“命令”框中，鍵入如下內容：dllhost.exe 在“命令參數”框中，鍵入參數 /ProcessID，繼之以應用程序 ID（library XXX）上的GUID。例如：/ProcessID:{3D14228C-FBE1-11D0-995D-0C04FD919C1} 單擊“確定”。這樣設置后就可以調試了。 如果客戶端是C#，再設置客戶端項目調試選項中可以調試非托管代碼。
總是出現"char * __stdcall _com_util::ConvertBSTRToString的錯誤
只要在某個文件中添加對comdef.h的包含就可以，這個頭文件會鏈接庫，僅包含comutil.h并不會鏈接相應的庫。
7-27日：
C# .net framework4.0 傳遞SAFEARRAY的問題。
I am able to call a COM interface method using SAFEARRAY(BSTR) as input. If I define instead a simple (containing only some BSTR-s fields) STRUCT to pass into the COM I get "[System.ArgumentException] = {"The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG))"
The call to my COM server is not made because as it seems the arguments from client does not match the expected arguments on server: E_INVALIDARG
Here is my declaration in IDL:
typedef enum UserEntityType
{
User,
Group,
IPAddress
} UserEntityType;
[
uuid(4786F77E-BA5F-4806-B224-12AA8601A5B1)
]
typedef struct UserEntity
{
UserEntityType EntityType;
BSTR Value;
} UserEntity;
[id(9)] HRESULT SetUsers([in] SAFEARRAY(UserEntity) input);
The exception is thrown at run-time when a C# 4 client calls SetUsers().
solution:The problem was in the C# client that was using the exe COM server where
SetUsers([in] SAFEARRAY(UserEntity) input)
was defined. In order to fix this (at least for .NET 4.0) one has to change the following property of the imported COM server: Embed Interop Types = False