Delphi ActiveX的DAX Error之终极解决方法

   

  一般对DAX Error的解释是：Delphi 的 ActiveX一个进程只有一个 ParkingWindow，需要把VCL里的axctrls.pas 的ParkingWindow函数进行修改:

function ParkingWindow: HWND;

var

TempClass: TWndClass;

ParkingName : String;

begin

Result := xParkingWindow;

if Result <> 0 then Exit;

// fix Dax error : accessviolation (win2k, win xp)

ParkingName := 'DAXParkingWindow_' + Format('%p', [@ParkingWindowProc]);

FillChar(TempClass, sizeof(TempClass), 0);

if not GetClassInfo(HInstance, PChar(ParkingName), TempClass) then // fix Dax error : accessviolation (win2k, win xp)

begin

TempClass.hInstance := HInstance;

TempClass.lpfnWndProc := @ParkingWindowProc;

TempClass.lpszClassName := PChar(ParkingName); // fix Dax error : accessviolation (win2k, win xp)

if Windows.RegisterClass(TempClass) = 0 then

raise EOutOfResources.Create(SWindowClass);

end;

xParkingWindow := CreateWindowEx(WS_EX_TOOLWINDOW, TempClass.lpszClassName, nil,

WS_POPUP, GetSystemMetrics(SM_CXSCREEN) div 2,

GetSystemMetrics(SM_CYSCREEN) div 2, 0, 0, 0, 0, HInstance, nil);

SetWindowPos(xParkingWindow, 0, 0, 0, 0, 0, SWP_NOACTIVATE or SWP_NOREDRAW

or SWP_NOZORDER or SWP_SHOWWINDOW);

Result := xParkingWindow;

end;

  但是做了以上修改，并没有解决全部问题，仍然会报DAX Error，经过调试和试验发现问题出在“if Result <> 0 then Exit”这句上，还需要将其注释或去掉，重新编译即可。