好的,首先这不是 Vcl 样式错误,这是一个 VCL 错误。即使禁用了 Vcl 样式,也会出现此问题。
该问题位于TCustomMDIMenuButton.Paint
使用旧的方法DrawFrameControl http://msdn.microsoft.com/en-us/library/windows/desktop/dd162480%28v=vs.85%29.aspxWinAPi 方法绘制标题按钮。
procedure TCustomMDIMenuButton.Paint;
begin
DrawFrameControl(Canvas.Handle, ClientRect, DFC_CAPTION,
MouseStyles[MouseInControl] or ButtonStyles[ButtonStyle] or
PushStyles[FState = bsDown]);
end;
作为解决方法,您可以使用以下方法修补此方法detour然后使用以下方法实现新的绘制方法StylesServices
.
只需将此单元添加到您的项目中即可。
unit PatchMDIButtons;
interface
implementation
uses
System.SysUtils,
Winapi.Windows,
Vcl.Themes,
Vcl.Styles,
Vcl.ActnMenus;
type
TCustomMDIMenuButtonClass= class(TCustomMDIMenuButton);
TJumpOfs = Integer;
PPointer = ^Pointer;
PXRedirCode = ^TXRedirCode;
TXRedirCode = packed record
Jump: Byte;
Offset: TJumpOfs;
end;
PAbsoluteIndirectJmp = ^TAbsoluteIndirectJmp;
TAbsoluteIndirectJmp = packed record
OpCode: Word;
Addr: PPointer;
end;
var
PaintMethodBackup : TXRedirCode;
function GetActualAddr(Proc: Pointer): Pointer;
begin
if Proc <> nil then
begin
if (Win32Platform = VER_PLATFORM_WIN32_NT) and (PAbsoluteIndirectJmp(Proc).OpCode = $25FF) then
Result := PAbsoluteIndirectJmp(Proc).Addr^
else
Result := Proc;
end
else
Result := nil;
end;
procedure HookProc(Proc, Dest: Pointer; var BackupCode: TXRedirCode);
var
n: NativeUInt;
Code: TXRedirCode;
begin
Proc := GetActualAddr(Proc);
Assert(Proc <> nil);
if ReadProcessMemory(GetCurrentProcess, Proc, @BackupCode, SizeOf(BackupCode), n) then
begin
Code.Jump := $E9;
Code.Offset := PAnsiChar(Dest) - PAnsiChar(Proc) - SizeOf(Code);
WriteProcessMemory(GetCurrentProcess, Proc, @Code, SizeOf(Code), n);
end;
end;
procedure UnhookProc(Proc: Pointer; var BackupCode: TXRedirCode);
var
n: NativeUInt;
begin
if (BackupCode.Jump <> 0) and (Proc <> nil) then
begin
Proc := GetActualAddr(Proc);
Assert(Proc <> nil);
WriteProcessMemory(GetCurrentProcess, Proc, @BackupCode, SizeOf(BackupCode), n);
BackupCode.Jump := 0;
end;
end;
procedure PaintPatch(Self: TObject);
const
ButtonStyles: array[TMDIButtonStyle] of TThemedWindow = (twMDIMinButtonNormal, twMDIRestoreButtonNormal, twMDICloseButtonNormal);
var
LButton : TCustomMDIMenuButtonClass;
LDetails: TThemedElementDetails;
begin
LButton:=TCustomMDIMenuButtonClass(Self);
LDetails := StyleServices.GetElementDetails(ButtonStyles[LButton.ButtonStyle]);
StyleServices.DrawElement(LButton.Canvas.Handle, LDetails, LButton.ClientRect);
end;
procedure HookPaint;
begin
HookProc(@TCustomMDIMenuButtonClass.Paint, @PaintPatch, PaintMethodBackup);
end;
procedure UnHookPaint;
begin
UnhookProc(@TCustomMDIMenuButtonClass.Paint, PaintMethodBackup);
end;
initialization
HookPaint;
finalization
UnHookPaint;
end.
结果将是