修正XPMenu的两个Bug

XPMenu是大名鼎鼎的Dephi第三方界面控件，最近在使用中发现了几个Bug，并对其中的两个进行修正。

1、首先，是绘制菜单和工具栏图标时，会将图像白色部分作为透明色，导致图像缺损非常难看，如下图所示：
XPMenu图标透明Bug示图

　　查看XPMenu的源代码，图标是通过TXPMenu.DrawIcon函数绘制的，函数内计算了图标显示的位置、调用GrayBitmap、DimBitmap、DrawBitmapShadow等函数对图像进行了处理，并将图像的Transparent设为true，再查看GrayBitmap、DimBitmap、DrawBitmapShadow函数并没有发现会导致透明色计算错误的代码。再往回找，终于在TXPMenu.MenueDrawItem和TXPMenu.ToolBarDrawButton里发现了问题，先来看看TXPMenu.MenueDrawItem：

procedure TXPMenu.MenueDrawItem(Sender: TObject; ACanvas: TCanvas; ARect: TRect;
Selected: Boolean);
beign
.....
//-------
if HasBitmap then
    begin
      B.Width := FMenuItem.Bitmap.Width;
      B.Height := FMenuItem.Bitmap.Height;
// +jt
     //B.Canvas.Brush.Color := FTransparentColor; // ACanvas.Brush.Color;
     B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <ashert@yadasystems.com>
     B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));
     FMenuItem.Bitmap.Transparent := true;
     FMenuItem.Bitmap.TransparentMode := tmAuto;
      B.Canvas.Draw(0,0,FMenuItem.Bitmap);
// +jt
    end;

if HasImgLstBitmap then
begin
{$IFDEF VER5U}
    if FMenuItem.Parent.SubMenuImages <> nil then
    begin
      ImgListHandle := FMenuItem.Parent.SubMenuImages.Handle;
      ImgIndex := FMenuItem.ImageIndex;

      B.Width := FMenuItem.Parent.SubMenuImages.Width;
      B.Height := FMenuItem.Parent.SubMenuImages.Height;
     // B.Canvas.Brush.Color := FTransparentColor; // ACanvas.Brush.Color; // +jt
      B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <ashert@yadasystems.com>
      B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));
      ImageList_DrawEx(ImgListHandle, ImgIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_Transparent);

    end
    else
{$ENDIF}
    if FMenuItem.Parent.GetParentMenu.Images <> nil then
    begin
      ImgListHandle := FMenuItem.Parent.GetParentMenu.Images.Handle;
      ImgIndex := FMenuItem.ImageIndex;

      B.Width := FMenuItem.Parent.GetParentMenu.Images.Width;
      B.Height := FMenuItem.Parent.GetParentMenu.Images.Height;
      //B.Canvas.Brush.Color := FTransparentColor; //ACanvas.Pixels[2,2]; // +jt
      B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <ashert@yadasystems.com>
      B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));
      ImageList_DrawEx(ImgListHandle, ImgIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_Transparent);

    end;

end;
......
if (B <> nil) and (B.Width > 0) then // X
    DrawIcon(FMenuItem, ACanvas, B, IconRect,
      Selected or DrawTopMenuBorder, False, FMenuItem.Enabled, FMenuItem.Checked,
      FTopMenu, FMenu.IsRightToLeft);
......
end;

　　很明显，除了XPMenu的作者之外，+jt、Asher和X均对代码进行过修改，问题就出在+jk的修改的这段代码里，它先用B（TBitmap）.Canvas.Pixels[0, B.Height - 1]处的颜色填充了整个B，然后再把要显示的图标画到B里去，后面会调用DrawIcon把图标显示出来，可惜+jt计算错误，当时的B（TBitmap）.Canvas.Pixels[0, B.Height - 1]值正是$FFFFFF（白色），以ILD_Transparent参数调用ImageList_DrawEx时会把原图标底色（比如上图的粉红色）去掉，那么DrawIcon绘制的图标底色就是白色的，最后图标所有白色部分被挖空了。+jt真是好心做坏事了。
　　原因找到了，现在直接把+jt那部分代码去掉即可。原程序变为：

procedure TXPMenu.MenueDrawItem(Sender: TObject; ACanvas: TCanvas; ARect: TRect;
Selected: Boolean);
beign
.....
//-------
if HasBitmap then
    begin
      B.Width := FMenuItem.Bitmap.Width;
      B.Height := FMenuItem.Bitmap.Height;
{Modify: Conch 2004-12-16 画出的图标透明颜色有错
// +jt
     //B.Canvas.Brush.Color := FTransparentColor; // ACanvas.Brush.Color;
     B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <ashert@yadasystems.com>
     B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));
     FMenuItem.Bitmap.Transparent := true;
     FMenuItem.Bitmap.TransparentMode := tmAuto;
}
      B.Canvas.Draw(0,0,FMenuItem.Bitmap);
// +jt
    end;

if HasImgLstBitmap then
begin
{$IFDEF VER5U}
    if FMenuItem.Parent.SubMenuImages <> nil then
    begin
      ImgListHandle := FMenuItem.Parent.SubMenuImages.Handle;
      ImgIndex := FMenuItem.ImageIndex;

      B.Width := FMenuItem.Parent.SubMenuImages.Width;
      B.Height := FMenuItem.Parent.SubMenuImages.Height;
{Modify: Conch 2004-12-16 画出的图标透明颜色有错
     // B.Canvas.Brush.Color := FTransparentColor; // ACanvas.Brush.Color; // +jt
      B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <ashert@yadasystems.com>
      B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));
      ImageList_DrawEx(ImgListHandle, ImgIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_Transparent);
}
      ImageList_DrawEx(ImgListHandle, ImgIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_NORMAL);
//Conch

    end
    else
{$ENDIF}
    if FMenuItem.Parent.GetParentMenu.Images <> nil then
    begin
      ImgListHandle := FMenuItem.Parent.GetParentMenu.Images.Handle;
      ImgIndex := FMenuItem.ImageIndex;

      B.Width := FMenuItem.Parent.GetParentMenu.Images.Width;
      B.Height := FMenuItem.Parent.GetParentMenu.Images.Height;
{Modify: Conch 2004-12-16 画出的图标透明颜色有错
      //B.Canvas.Brush.Color := FTransparentColor; //ACanvas.Pixels[2,2]; // +jt
      B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <ashert@yadasystems.com>
      B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));
      ImageList_DrawEx(ImgListHandle, ImgIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_Transparent);
}
      ImageList_DrawEx(ImgListHandle, ImgIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_NORMAL);
//Conch

    end;

end;
......
if (B <> nil) and (B.Width > 0) then // X
    DrawIcon(FMenuItem, ACanvas, B, IconRect,
      Selected or DrawTopMenuBorder, False, FMenuItem.Enabled, FMenuItem.Checked,
      FTopMenu, FMenu.IsRightToLeft);
......
end;

　　TXPMenu.ToolBarDrawButton的原因也是一样。

procedure TXPMenu.ToolBarDrawButton(Sender: TToolBar;
Button: TToolButton; State: TCustomDrawState; var DefaultDraw: Boolean);
begin
      if CanDraw then
      begin {CanDraw}
{Modify: Conch 2004-12-16  画出的图标透明颜色有错
       // B.Canvas.Brush.Color := TransparentColor; // ACanvas.Brush.Color; // +jt
        B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <ashert@yadasystems.com>
        B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));
        ImageList_DrawEx(ImglstHand, Button.ImageIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_Transparent);
}
        ImageList_DrawEx(ImglstHand, Button.ImageIndex,
        B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_NORMAL);
//Conch
......
end;

2、第二个问题是菜单的阴影太呆板，是固定的一层灰色块（当然是指WinXP以前的系统），如图：
XPMenu菜单阴影问题修正前

　　菜单阴影是由TXPMenu.DrawWindowBorder函数绘制的。这里可以看到+jt进行过修改，不过+jt的注释方式有点特别，看不出那些在作者的原代码，那些是+jt改过的，不过可以肯定+jt下了不少苦功。这个函数把Windows来的那个3D边框去掉，变成平面的OfficeXP风格菜单。若果要改为像WinXP菜单的那种通过与背景像素混合的得到的阴影效果，必须对源码进行大改，但使用第三方控件目的是为了方便省事，如果那样做的话就太有违初衷了。因此我这里用了一种折衷的办法，把灰色面积减少，这样看起来就顺眼多了。最终效果如下图：
XPMenu菜单阴影问题修正后
　　修改后的TXPMenu.DrawWindowBorder函数：

procedure TXPMenu.DrawWindowBorder(hWnd: HWND; IsRightToLeft: boolean);
var
WRect: TRect;
dCanvas: TCanvas;
wDC: HDC; // +jt

regiontype: integer; // +jt
r1,r2,wr,region: HRGN; // +jt
rgnr: TRect; // +jt
begin

if (hWnd <= 0) or (FSettingWindowRng) then
begin
exit;
end;
// +jt
wDC := GetWindowDC(hWnd); //GetDesktopWindow
if wDC=0 then exit;
// +jt
FSettingWindowRng :=true; // +jt
dCanvas := TCanvas.Create;
try
   dCanvas.Handle := wDC; // +jt
    GetWindowRect(hWnd, WRect);
// +jt
   WRect.Right := WRect.Right-WRect.Left;
   WRect.Bottom := WRect.Bottom-WRect.Top;
   WRect.Top:=0;
   WRect.Left:=0;
    if GetWindowLong(hWnd,GWL_WNDPROC)<>integer(@MenuWindowProc) then
   begin
     SetWindowLong(hWnd,GWL_USERDATA,GetWindowLong(hWnd,GWL_WNDPROC));
     SetWindowLong(hWnd,GWL_WNDPROC,integer(@MenuWindowProc));
   end;
{Modify: Conch 2004-11-04 画出的阴影太难看了
    if not IsWXP then
   begin
      wr:= CreateRectRgn(0,0,0,0);
     regiontype := GetWindowRgn(hWnd, wr);
     GetRgnBox(wr,rgnr);
     DeleteObject(wr);
      if (regionType = ERROR) or (abs(rgnr.Right-WRect.Right)>5) or (abs(rgnr.Bottom-WRect.Bottom)>5) then
     begin
       region:= CreateRectRgn(0,0,0,0);
       r1:=CreateRectRgn(WRect.Left,WRect.Top,WRect.Right-2,WRect.Bottom-2);
       r2:=CreateRectRgn(WRect.Left+2,WRect.Top+2,WRect.Right,WRect.Bottom);
       CombineRgn(region,r1,r2,RGN_OR);
       DeleteObject(r1);
       DeleteObject(r2);
        SetWindowRgn(hWnd,region,true);
      end;
// +jt
      Dec(WRect.Right, 2);
     Dec(WRect.Bottom, 2);
   end; // +jt
}
    dCanvas.Brush.Style := bsClear;
    dCanvas.Pen.Color := FMenuBorderColor;
   dCanvas.Rectangle(WRect.Left, WRect.Top, WRect.Right, WRect.Bottom);
    if IsRightToLeft then
   begin
      dCanvas.Pen.Color := FFIconBackColor;
     dCanvas.MoveTo(WRect.Right - 3, WRect.Top + 2);
     dCanvas.LineTo(WRect.Right - 2, WRect.Bottom - 1);
    end
   else
   begin
     dCanvas.Pen.Color := FFIconBackColor;
     dCanvas.Rectangle(WRect.Left + 1, WRect.Top + 2, WRect.Left + 3, WRect.Bottom - 1);
   end;
// +jt
       StretchBlt(dCanvas.Handle,WRect.Left + 1,WRect.Top + 1,WRect.Right - WRect.Left-1,2,
                  dCanvas.Handle,WRect.Left + 1,WRect.Top + 3,WRect.Right - WRect.Left-1,1,SRCCOPY);
        if IsWXP then
       begin
         StretchBlt(dCanvas.Handle,WRect.Left + 1,WRect.Bottom - 3,WRect.Right - WRect.Left-1,2,
                    dCanvas.Handle,WRect.Left + 1,WRect.Top + 3,WRect.Right - WRect.Left-1,1, SRCCOPY);
         dCanvas.Pen.Color := FFColor;
         dCanvas.Rectangle(WRect.Right - 3, WRect.Top+1, WRect.Right - 1, WRect.Bottom-1);
       end;
// +jt
{Modify: Conch 2004-11-04 画出的阴影太难看了
    Inc(WRect.Right, 2);
   Inc(WRect.Bottom, 2);
    if not IsWXP then // +jt
   begin // +jt
     dCanvas.Pen.Color := FMenuShadowColor;
     dCanvas.Rectangle(WRect.Left + 2, WRect.Bottom, WRect.Right, WRect.Bottom - 2);
     dCanvas.Rectangle(WRect.Right - 2, WRect.Bottom, WRect.Right, WRect.Top + 2);
   end; // +jt
}

finally
   ReleaseDC(hWnd, wDC); // +jt
   dCanvas.Free;
FSettingWindowRng :=false;
end;

end;