vc的回调函数如何在delphi中应用(50分)

vc中调用函数：
HIK_PLAYM4_API BOOL __stdcall Hik_PlayM4_SetDisplayCallBack(LONG nPort,void (CALLBACK* DisplayCBFun)(long nPort,char * pBuf,long nSize,long nWidth,long nHeight,long nStamp,long nType,long nReserved));
vc中回调函数
void (CALLBACK* DisplayCBFun)(long nPort,char * pBuf,long nSize,long nWidth,long nHeight,long nStamp,long nType,long nReserved)
***********************************************************************
转换成delphi
回调函数参数
DisplayCBFun = procedure(nPort: integer; pBuf: PChar; nSize: integer; nWidth: integer; nHeight: integer; nStamp: integer; nType: integer; nReserved: integer);
调用函数
function Hik_PlayM4_SetDisplayCallBack(nPort: integer; nDisplayCBFun: DisplayCBFun): LongBool; stdcall;
回调函数
procedure DisplayCBFun1(nPort: integer; pBuf: PChar; nSize: integer; nWidth: integer; nHeight: integer; nStamp: integer; nType: integer; nReserved: integer);stdcall;
调用：
Hik_PlayM4_SetDisplayCallBack(0,@DisplayCBFun1)
这样有问题吗，希望高手指正
错误提示：
Variable required（需求变量）

关---注!!!

var
pf: DisplayCBFun;
begin
pf:= @DisplayCBFun1;
Hik_PlayM4_SetDisplayCallBack(0,pf);

试试，没调试过， 不过方法是这样，应该没错的

谢谢关注，我忘记 函数实现部分加“stdcall;”
procedure DisplayCBFun1(nPort: integer; pBuf: PChar; nSize: integer; nWidth: integer; nHeight: integer; nStamp: integer; nType: integer; nReserved: integer); stdcall;
begin
if SavePic=true then
begin
Hik_PLayM4_ConvertToBmpFile(pBuf,nSize,nWidth,nHeight,nType,'D:/1.bmp') ;
SavePic:=false;
end
else
begin
// ShowMessage('222');
end;
end;
所以出现错误
谢谢关注，散分