C++ To Delphi

Question

typedef bool (__stdcall *fMessCallBack)(long lLoginID, char *pBuf,unsigned long dwBufLen, long dwUser);
H264_DVR_API bool H264_DVR_SetDVRMessCallBack(fMessCallBack cbAlarmcallback, unsigned long lUser);
请问这个用Delphi 怎么写？

Answer 1

type
  TfMessCallBack = function(lLoginID: integer; pBuf: PChar; dwBufLen: integer; dwUser: integer): Boolean; stdcall;
  TH264_DVR_SetDVRMessCallBack = function(cbAlarmcallback: fMessCallBack; lUser: integer): Boolean; stdcall;

Answer 2

应该是这样：type
  fMessCallBack = function(lLoginID: integer; pBuf: PChar; dwBufLen: integer; dwUser: integer): Boolean; stdcall;
  function H264_DVR_SetDVRMessCallBack(cbAlarmcallback: fMessCallBack; lUser: integer): Boolean; stdcall; external H264_DVR_API; //H264_DVR_API = 'MYDLL.dll';

Answer 3

再追问一句，怎么调用H264_DVR_SetDVRMessCallBack，第一个参数怎么写。

Answer 4

function MyfMessCallBack(lLoginID: integer; pBuf: PChar; dwBufLen: integer; dwUser: integer): Boolean;
begin
  Result := True;
  //do something
end;procedure TForm1.Button1Click(Sender: TObject);
var
  lUser: integer;
begin
  H264_DVR_SetDVRMessCallBack(@MyfMessCallBack, lUser);
end;