文档介绍：//ToolStripSplitButton是标准按钮和下拉按钮的组合,各自工作,但有联系,感觉上后者是没有向下箭头ToolStripDropDownButton;ToolStripDropDownButton只含有一个按钮,可以选择有没有向下箭头的标志,单击时显示关联的 ToolStripDropDown 的控件。两者均可改变箭头标志在做还是在右。//(||,true);//=true;//attributemodfiedbyProtected//手工双缓冲Bitmapbmp=newBitmap(600,600);Graphicsg=(bmp);();().DrawImage(bmp,0,0);//这句是关键,不能à在OnPaint里画BitBmp在这里调InvalidateInvalidate(Rectangle)//规定区域重绘,boBox1=(ComboBox)sender;(SenderasSomeObject).Method()=("微软雅黑",72F,,,((byte)(134)));=newFont("微软雅黑",fontSize);//自定义控件背景透明SetStyle(,true);SetStyle(,true);=;//=();//(Point);(int,int);(Point);//截获标题栏消息,;;[DllImport("")]privatestaticexternIntPtrGetWindowDC(IntPtrhWnd);[DllImport("")]privatestaticexternintReleaseDC(IntPtrhWnd,IntPtrhDC);privateconstintWM_NCPAINT=0x0085;privateconstintWM_NCACTIVATE=0x0086;privateconstintWM_NCLBUTTONDOWN=0x00A1;protectedoverridevoidWndProc(refMessagem){(refm);RectanglevRectangle=newRectangle((Width-75)/2,3,75,25);switch(){caseWM_NCPAINT:caseWM_NCACTIVATE:IntPtrvHandle=GetWindowDC();GraphicsvGraphics=(vHandle);(newLinearGradientBrush(vRectangle,,,),vRectangle);StringFormatvStringFormat=newStringFormat();=;=;("About",Font,