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：

　　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" <[email protected]>      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   {$IFDEF VER5U}     if FMenuItem.Parent.SubMenuImages <> nil then     begin       ImgListHandle := FMenuItem.Parent.SubMenuImages.Handle;       ImgIndex := FMenuItem.ImageIndex;       B.Width := FMenuItem.Parent.SubMenuImages.Width;       B.Height := FMenuItem.Parent.SubMenuImages.Height;      // B.Canvas.Brush.Color := FTransparentColor; // ACanvas.Brush.Color; // +jt       B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <[email protected]>       B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));       ImageList_DrawEx(ImgListHandle, ImgIndex,         B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_Transparent);     end     else   {$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" <[email protected]>       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" <[email protected]>      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   {$IFDEF VER5U}     if FMenuItem.Parent.SubMenuImages <> nil then     begin       ImgListHandle := FMenuItem.Parent.SubMenuImages.Handle;       ImgIndex := FMenuItem.ImageIndex;       B.Width := FMenuItem.Parent.SubMenuImages.Width;       B.Height := FMenuItem.Parent.SubMenuImages.Height; {Modify: Conch 2004-12-16 画出的图标透明颜色有错      // B.Canvas.Brush.Color := FTransparentColor; // ACanvas.Brush.Color; // +jt       B.Canvas.Brush.Color := B.Canvas.Pixels[0, B.Height - 1];//"Todd Asher" <[email protected]>       B.Canvas.FillRect(Rect(0, 0, B.Width, B.Height));       ImageList_DrawEx(ImgListHandle, ImgIndex,         B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_Transparent); }       ImageList_DrawEx(ImgListHandle, ImgIndex,         B.Canvas.Handle, 0, 0, 0, 0, clNone, clNone, ILD_NORMAL); //Conch     end     else   {$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" <[email protected]>       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" <[email protected]>         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：


　　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：

　　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;