CSharp扩展TrackBar控件显示不同风格

1、C#扩展TrackBar控件显示不同风格1.控件效果关注55%意同购买2.开发思路TrackBar控件没有像其他控件那样，直接提供给用户重绘的函数，要实现个性化的TrackBar控件直接继承 TrackBar控件，利用TrackBar的一些 Windows消息，获取TrackBar 控件的信息，然后自己完全重绘，这种方法的好处是保留TrackBar控件的标准操作和属性，但是需要比较清楚的了解TrackBar控件的 Windows消息。3 .源码介绍实现TrackBar控件显示不同风格需要的一些API消息。TrackBar控件相关的一些消息都是以TBM(TackBar Message)开头的，在

2、TrackBar控件的美化中，主要用到了以下三个消 息：TBM_GETCHANNELREC获取轨道的位置和大小。TBM_GETTHUMBRE(获取滑块的位置和大小。 TBM_GETNUMTICS获取刻度的总个数。要获取这些信息，只需要向TrackBar控件发送相应的消息即可，例如需要获取取轨道的位置和大小： Se ndMessage(hWnd, TBM.TBM_GETCHANNELRECT, 0, ref trackRect)。接下来就是重绘 TrackBar控件了。重绘TrackBar控件，需要重写 WndProc函数，在 WM_PAIN消息实现重绘就行了：/ <summary>

3、/接收消息/ </summary>/ <param name="m"></param>protected override void WndProc( ref Messagem)switch (m.Msg)case WI.WM_PAINT:if (!_bPainting)_bPainting =true ;PAINTSTRUCTs = new PAINTSTRUCTNativeMethods .BeginPaint(m.HWnd, ref ps);DrawTrackBar(m.HWnd);NativeMethods .ValidateRe

4、ct(m.HWnd, ref ps.rcPaint);NativeMethods .EndPaint(m.HWnd, ref ps);_bPainting =false ;m.Result =Result .TRUE;elsebase.WndProc( ref m);break;default :base.WndProc( ref m);break;DrawTrackBar函数的功能就是获取TrackBar控件的一些信息，然后分别调用四个函数来绘制TrackBar控件：OnRenderBackground 函数，绘制 TrackBar 控件的背景。OnRenderTick函数，绘制TrackB

5、ar控件的刻度。OnRenderTrack函数，绘制TrackBar控件的轨道。On Re nderThumb函数，绘制TrackBar控件的滑块。这四个函数都是可以重写的，如果想实现不同样式的TrackBar控件，重写这四个函数,可以相应的绘制。DrawTrackBar函数的具体代码:private void DrawTrackBar( IntPtr hWnd)ControlState state = ControlState .Normal;bool horizontal = base.Orientation = Orientation .Horizontal;ImageDc tempDc

6、 = new ImageDc( base.Width, base.Height); TrackRECTtrackRect = new TrackRECT(); TrackRECTthumbRect = new TrackRECT();Graphics g = Graphics .FromHdc(tempDc.Hdc);NativeMethods .SendMessage(hWnd, TBM.TBM_GETCHANNELRECT, 0r,ef trackRect);NativeMethods .SendMessage(hWnd, TBM.TBM_GETTHUMBRECT, 0r,ef thumb

7、Rect);Rectangle trackRectangle = horizontal ? trackRect.Rect :Rectangle .FromLTRB(trackRect.Top, trackRect.Left, trackRect.Bottom, trackRect.Right);if (ThumbHovering(thumbRect)if ( Helper .LeftKeyPressed()state = ControlState .Pressed;elsestate = ControlState .Hover;/绘制TrackBar控件的背景using ( PaintEven

8、tArgs pe = new PaintEventArgs (g, ClientRectangle)OnRenderBackground(pe);int ticks = NativeMethods .SendMessage(hWnd, TBM.TBM_GETNUMTICS, 0, 0);int thumbOffset = horizontal ? thumbRect.Rect.Width : thumbRect.Rect.Height;int trackWidth = trackRect.Right - trackRect.Left;if (ticks > 0)List <floa

9、t > tickPosList = new List <float >(ticks);float tickSpace = (trackWidth - thumbOffset) / ( float )(ticks - 1);float offset = trackRect.Left + thumbOffset / 2f;for (int pos = 0; pos < ticks; pos +)tickPosList.Add(offset + tickSpace * pos);/绘制TrackBar控件的刻度using ( PaintTickEventArgs pte =

10、new PaintTickEventArgs (g, trackRectangle, tickPosList)OnRenderTick(pte);int rangeMin = NativeMethods .SendMessage(hWnd, TBM.TBM_GETRANGEMIN, 0, 0);int rangeMax = NativeMethods .SendMessage(hWnd, TBM.TBM_GETRANGEMAX, 0, 0);int iRange = rangeMax - rangeMin + 1;if (iRange > 0)float rangeSpace = iRa

11、nge = 1 ? 0 : (trackWidth - thumbOffset) / (float )(iRange- 1);float rangeOffset = trackRect.Left + thumbOffset / 2f;/ 绘制 TrackBar 控件的轨道using ( PaintTrackEventArgs pe = new PaintTrackEventArgs (g, trackRectangle,rangeSpace, rangeOffset, rangeMin, rangeMax)OnRenderTrack(pe);/绘制TrackBar控件的滑块using ( Pa

12、intThumbEventArgs pe = new PaintThumbEventArgs (g, thumbRect.Rect, state)OnRenderThumb(pe);g.Dispose();IntPtr hDC = NativeMethods .GetDC(hWnd);NativeMethods .BitBlt(hDC, 0, 0, base.Width, base.Height, tempDc.Hdc, 0, 0,0xCC0020);NativeMethods .ReleaseDC(hWnd, hDC);tempDc.Dispose();扩展后的TrackBar控件还实现了一个ColorTable和Items属性，ColorTable :只要通过ColorTable设置相应的颜色，就可以得到不同颜色效果的TrackBar 控件了。Items :通过添加项，可以显示不同段的背景颜色。TrackBar控件的完整类视图:Tr ackBarExClass H>TrackBarffi字段s属性宜 ColorTable 冒 IsShow