After add external ActiveX controls, reference ActiveX classes discovered the problem
The following is his class declaration

 class CPlayer: public COleDispatchDriver 
{
Public: 
COleDispatchDriver CPlayer () {}//call the default constructor 
CPlayer (LPDISPATCH pDispatch) : COleDispatchDriver (pDispatch) {} 
CPlayer (const CPlayer& DispatchSrc) : COleDispatchDriver (dispatchSrc) {} 

//feature 
Public: 

//
Public: 
Void Open (LPCTSTR strUrl) 
{
The static BYTE parms []=VTS_BSTR; 
InvokeHelper (0 x1, DISPATCH_METHOD, VT_EMPTY, NULL, parms, strUrl); 
} 

}; 

Then I wrote in the code of CPlayer a;
A.O pen (_T (" E: \ \ 010. The video player servo drives with main components that 04 mp4 "));

Run after the prompt: Warning: attempt to call Invoke with NULL m_lpDispatch!

This is the reason why, I am a rookie, may be CPlayer (LPDISPATCH pDispatch) : COleDispatchDriver pDispatch (a) {} this reason, there are a great god can help next, please appreciate ~ ~ ~ ~ ~ ~ ~

CodePudding user response:

CreateDispatch