关于在ActiveX中调用URLDownloadtoFile的问题, 第一个参数应该怎么填写呢

[goldntman]

MSDN中说在ActiveX里调用的话，是不能传递NULL的，那这个pCaller应该怎么写？

[zgl7903]

试试看

LPUNKNOWN pCaller = NULL;
URLDownloadToFile(pCaller,szURL,szFileName

[oyljerry]

直接调用，如果有问题查看一下错误信息

[goldntman]

不行啊，失败，错误信息我还没看

[真相重于对错]

Syntax HRESULT URLDownloadToFile( LPUNKNOWN pCaller, LPCTSTR szURL, LPCTSTR szFileName, DWORD dwReserved, LPBINDSTATUSCALLBACK lpfnCB ); Parameters pCaller Pointer to the controlling IUnknown interface of the calling Microsoft ActiveX component (if the caller is an ActiveX component). If the calling application is not an ActiveX component, this value can be set to NULL. Otherwise, the caller is a Component Object Model (COM) object that is contained in another component (such as an ActiveX control within the context of an HTML page). This parameter represents the outermost IUnknown of the calling component. The function attempts the download within the context of the ActiveX client framework and allows the caller's container to receive callbacks on the progress of the download.

[wumn29]

反正是一个IUnknown*指针， 传入脚本引擎接口试一下 Activex里面可以获取到调用这个控件的脚本引擎接口指针的