想在暴风影音放电影时在上面写字，思路是先HOOK它的里面的CreateSurface,结果怎么HOOK也出错，后来用自己写的一个简单的DIRECTX的程序来调，发现如果我自己的HOOK函数如果不Const,Out这些东西还可以进去，但在真正调用原函数时会出错，要是加了进都进不去就出错，请看代码：
//这个函数定义时如果不加关键字：const 和out可以进去，
//但调用原函数时会出错，如果加了就进不去就会出错即：
//function MyCreateSurfaceEx(lpDDSurfaceDesc: TDDSurfaceDesc2;
// lplpDDSurface: IDirectDrawSurface7;
// pUnkOuter: IUnknown): HResult; stdcall;
function MyCreateSurfaceEx(const lpDDSurfaceDesc: TDDSurfaceDesc2;
out lplpDDSurface: IDirectDrawSurface7;
pUnkOuter: IUnknown): HResult; stdcall;
type
TNewCreateSurfaceEx=function(const lpDDSurfaceDesc: TDDSurfaceDesc2;
out lplpDDSurface: IDirectDrawSurface7;
pUnkOuter: IUnknown): HResult; stdcall;
begin
asm
pushad
pushfd
end;
showmessage('MyCreateSurfaceEx Enter');
asm
popad
popfd
end;
Result:=TNewCreateSurfaceEx(OldCreateSurfaceEx)(lpDDSurfaceDesc,lplpDDSurface,pUnkOuter
showmessage('MyCreateSurfaceEx Exit');
end;
//
function MyDirectDrawCreateEx(lpGUID: PGUID; out lplpDD: IDirectDraw7;
const iid: TGUID; pUnkOuter: IUnknown): HResult; stdcall;
type
TNewDirectDrawCreateEx=function(lpGUID: PGUID; out lplpDD: IDirectDraw7;
const iid: TGUID; pUnkOuter: IUnknown): HResult; stdcall;
begin
//showmessage('MyDirectDrawCreateEx');
Hook[2].UnHook;
MylpDD:=THookIDirectDraw7.Create(lpGUID,iid,pUnkOuter);
Result := TNewDirectDrawCreateEx(Hook[2].BaseAddr)(lpGUID, lplpDD, iid, pUnkOuter);
Hook[2].Hook;
if Result<>DD_OK then Exit;
HookVirtualTable(Pointer(lplpDD),6,@MyCreateSurfaceEx,OldCreateSurfaceEx);
//showmessage('lplpDD:='+inttostr(dword(lplpDD)));
end;
procedure HookVirtualTable(lpDD:Pointer;Index:Byte;NewFunc:Pointer;var OldFunc:Dword);
begin
OldFunc:=PWord(Dword(lpDD^)+Index*4)^;
PDword(Dword(lpDD^)+Index*4)^:=Dword(NewFunc);
end;
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