Treeview控件失去焦点，将选择的节点设置为高亮显示

修改TreeView的属性

1 this.treeView1.HideSelection = false;
2 this.treeView1.DrawMode = TreeViewDrawMode.OwnerDrawText;

添加treeView1_DrawNode事件

1 private void treeView1_DrawNode(object sender, DrawTreeNodeEventArgs e)
2 {
3   e.DrawDefault = true;//由操作系统绘制节点，默认值为false
4 }

 1 private void treeView1_DrawNode(object sender, DrawTreeNodeEventArgs e)
 2 {
 3     if ((e.State & TreeNodeStates.Selected) != 0)
 4     {
 5         e.Graphics.FillRectangle(Brushes.DodgerBlue, e.Node.Bounds);
 6 
 7         Font nodeFont = e.Node.NodeFont;
 8         if (nodeFont == null) nodeFont = ((TreeView)sender).Font;
 9         e.Graphics.DrawString(e.Node.Text, nodeFont, Brushes.White, Rectangle.Inflate(e.Bounds, 2, 0));
10     }
11     else
12     {
13         e.DrawDefault = true;
14     }
15 
16     if ((e.State & TreeNodeStates.Focused) != 0)
17     {
18         using (Pen focusPen = new Pen(Color.White))
19         {
20             focusPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
21             Rectangle focusBounds = e.Node.Bounds;
22             focusBounds.Size = new Size(focusBounds.Width - 1,
23             focusBounds.Height - 1);
24             e.Graphics.DrawRectangle(focusPen, focusBounds);
25         }
26     }
27 }