分析:
VCL中Menus.pas单元的代码,看到如下语句
procedure TMenuItem.AdvancedDrawItem(ACanvas: TCanvas; ARect: TRect;
State: TOwnerDrawState; TopLevel: Boolean);
//...
if Win2K and (odNoAccel in State) then
DrawStyle := DrawStyle or DT_HIDEPREFIX;
//...
DT_HIDEPREFIX就是隐藏下划线 //用DrawText()测试一下就知道
在设置Images属性后(odNoAccel in State)为真
看来需要自绘菜单,响应OnAdvancedDrawItem事件
当然,自绘菜单的代码写起来就多了,还好AdvancedDrawItem()声明在protected部分
我们可以通过继承TMenuItem来访问AdvancedDrawItem()
type
TMenuItemAccess = class(TMenuItem);
现在就要想办法使那个条件不成立,先从Win2K入手
当Images设置后"Win2K and (odNoAccel in State)"这个条件成立
分析单元中Win2K变量是这样得到的
Win2K := (Win32MajorVersion > 4) and (Win32Platform = VER_PLATFORM_WIN32_NT);
那么我们就可以通过修改Win32MajorVersion或者Win32Platform常量使其不成立
参考代码:
type
TForm1 = class(TForm)
MainMenu1: TMainMenu;
ImageList1: TImageList;
MenuItemfile: TMenuItem;
MenuItemNew: TMenuItem;
MenuItemOpen: TMenuItem;
PopupMenu1: TPopupMenu;
MenuItemCopy: TMenuItem;
MenuItemPaste: TMenuItem;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
procedure MenuItemAdvancedDrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; State: TOwnerDrawState);
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
type
TMenuItemAccess = class(TMenuItem);
procedure TForm1.MenuItemAdvancedDrawItem(Sender: TObject; ACanvas: TCanvas;
ARect: TRect; State: TOwnerDrawState);
var
vWin32Platform: Integer;
begin
vWin32Platform := PInteger(@Win32Platform)^;
PInteger(@Win32Platform)^ := -1;
TMenuItemAccess(Sender).OnAdvancedDrawItem := nil;
try
TMenuItemAccess(Sender).AdvancedDrawItem(ACanvas, ARect, State,
TMenuItemAccess(Sender).GetParentComponent is TMainMenu);
finally
TMenuItemAccess(Sender).OnAdvancedDrawItem := MenuItemAdvancedDrawItem;
PInteger(@Win32Platform)^ := vWin32Platform;
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
var
I: Integer;
begin
for I := 0 to ComponentCount - 1 do
if Components[I] is TMenuItem then
TMenuItem(Components[I]).OnAdvancedDrawItem := MenuItemAdvancedDrawItem
else if Components[I] is TMenu then
TMenu(Components[I]).OwnerDraw := True;
end;