重写C#TreeView控件,提升TreeView控件档次

我改过的TreeView控件的效果如下:

鼠标没有放到树额节点上

 

鼠标放到树的节点上

数节点的展开

 

展开树的子节点

 

鼠标放到数的节点上

 

下面是画上下箭头  的代码

//父节点的画箭头
      private void DrawParentNodeArrow(DrawTreeNodeEventArgs e, int Direction)
      {
          Graphics g = e.Graphics;
          g.SmoothingMode = SmoothingMode.AntiAlias;
          GraphicsPath path = new GraphicsPath();
          Point[] pt;

          if (Direction == ParentNodeArrowDirection.Up)
          {
              pt = new Point[3] { new Point(e.Bounds.X+e.Bounds.Width-22,(e.Bounds.Height/2)+2+e.Bounds.Y),
                      new Point(e.Bounds.X+e.Bounds.Width-10, (e.Bounds.Height/2)+2+e.Bounds.Y),
                      new Point(e.Bounds.X+e.Bounds.Width-16, (e.Bounds.Height/2)-4+e.Bounds.Y)
                  };
          }
          else if (Direction == ParentNodeArrowDirection.Down)
          {
              pt = new Point[3] { new Point(e.Bounds.X+e.Bounds.Width-22,(e.Bounds.Height/2)-2+e.Bounds.Y),
                      new Point(e.Bounds.X+e.Bounds.Width-10, (e.Bounds.Height/2)-2+e.Bounds.Y),
                      new Point(e.Bounds.X+e.Bounds.Width-16, (e.Bounds.Height/2)+4+e.Bounds.Y) };
          }
          else
          {
              return;
          }
          path.AddPolygon(pt);
          g.FillPath(new SolidBrush(Color.Black), path);
      }

 

子节点的中箭头的画法

//子节点的箭头
       private void DrawChildNodeArrow(int i缩进, DrawTreeNodeEventArgs e, int Direction)
       {
           Graphics g = e.Graphics;
           g.SmoothingMode = SmoothingMode.AntiAlias;
           GraphicsPath path = new GraphicsPath();
           Point[] pt;
           if (Direction == ChileNodeArrowDirection.Right)
           {
               pt = new Point[3] { new Point(e.Bounds.X+i缩进-12,e.Bounds.Y+(e.Bounds.Height)/2-4),
                       new Point(e.Bounds.X+i缩进-12, e.Bounds.Y+(e.Bounds.Height)/2+4),
                       new Point(e.Bounds.X+i缩进-6, e.Bounds.Y+(e.Bounds.Height)/2)};
               path.AddPolygon(pt);
               g.DrawPath(new Pen(Color.Black), path);
           }
           else if (Direction == ChileNodeArrowDirection.RightDown)
           {
               pt = new Point[3] { new Point(e.Bounds.X+i缩进-12,e.Bounds.Y+(e.Bounds.Height/2)+4),
                       new Point(e.Bounds.X+i缩进-4, e.Bounds.Y+(e.Bounds.Height/2)+4),
                       new Point(e.Bounds.X+i缩进-4, e.Bounds.Y+(e.Bounds.Height/2)-4)};
               path.AddPolygon(pt);
               g.FillPath(new SolidBrush(Color.Black), path);
           }
           else
           {
               return;
           }

       }

 

 

最重要的就是画树的节点了

      protected override void OnDrawNode(DrawTreeNodeEventArgs e)
      {
          Font f = null;
          int i缩进 = 0;
          if (e.Node.Parent == null)
          {
              Color gradientBegin = Color.FromArgb(203, 225, 252);
              Color gradientEnd = Color.FromArgb(125, 165, 224);
              if ((e.State & TreeNodeStates.Hot) != 0)
              {
                  gradientBegin = Color.FromArgb(255, 255, 222);
                  gradientEnd = Color.FromArgb(255, 203, 136);
                  f = new Font(FontFamily.GenericSansSerif, 10, FontStyle.Bold);
              }
              else
              {
                  f = new Font(FontFamily.GenericSansSerif, 10, FontStyle.Regular);
              }
              using (Brush b = new LinearGradientBrush(e.Bounds, gradientBegin,
                gradientEnd, LinearGradientMode.Vertical))
              {
                  e.Graphics.FillRectangle(b, e.Bounds);
              }
              //画箭头
              if (((e.State & TreeNodeStates.Hot) != 0) && e.Node.Nodes.Count > 0)
              {
                  if (e.Node.IsExpanded)
                  {
                      DrawParentNodeArrow(e, ParentNodeArrowDirection.Up);
                  }
                  else
                  {
                      DrawParentNodeArrow(e, ParentNodeArrowDirection.Down);
                  }
              }
              i缩进 = 0;
          }
          else
          {
              if ((e.State & TreeNodeStates.Hot) != 0)
              {
                  Color gradientBegin = Color.FromArgb(255, 255, 255);
                  //Color gradientBegin = Color.FromArgb(190, 227, 253);
                  Color gradientEnd = Color.FromArgb(190, 227, 253);

                  using (Brush b = new LinearGradientBrush(e.Bounds, gradientBegin,
                    gradientEnd, LinearGradientMode.Vertical))
                  {
                      e.Graphics.FillRectangle(b, e.Bounds);
                  }
                  f = new Font(FontFamily.GenericSansSerif, 10, FontStyle.Bold);
              }
              else
              {
                  e.Graphics.FillRectangle(new SolidBrush(Color.White), e.Bounds);
                  f = new Font(FontFamily.GenericSansSerif, 10, FontStyle.Regular);
              }

              i缩进 = Node级次(e.Node) * Indent;
              //画箭头
              if (e.Node.Nodes.Count > 0)
              {
                  if (e.Node.IsExpanded)
                  {
                      DrawChildNodeArrow(i缩进, e, ChileNodeArrowDirection.RightDown);
                  }
                  else
                  {
                      DrawChildNodeArrow(i缩进, e, ChileNodeArrowDirection.Right);
                  }
              }
          }
          //画文字         
          e.Graphics.DrawString(e.Node.Text, f, new SolidBrush(Color.Black), e.Bounds.X + i缩进, e.Bounds.Y + Convert.ToInt32((e.Bounds.Height - f.GetHeight()) / 2 + 1));
      }