The ultimate solution to Dax error of Delphi ActiveX

Generally, Dax error is interpreted as follows: in Delphi ActiveX, a process has only one parkingwindow, And the parkingwindow function of axctrls. PAS in VCL needs to be modified:

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: = createmediawex (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;

However, if the preceding modification does not solve all the problems, a Dax error will still be reported. After debugging and testing, the problem is found in the sentence "If result <> 0 Then exit, you also need to comment out or remove it and re-compile it.