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NewTreeView.cs:
public partial class NewTreeView : TreeView
{
Color backColor = Color.FromArgb(227, 251, 244);
Font foreFont = new Font("微软雅黑", 9F, FontStyle.Bold);
Brush foreBrush = new SolidBrush(Color.FromArgb(81, 81, 81));
Brush recBrush = new SolidBrush(Color.FromArgb(82, 218, 163));
Brush recSelectedBrush = new SolidBrush(Color.FromArgb(248, 248, 255));
Pen recPen = new Pen(new SolidBrush(Color.FromArgb(226, 226, 226)));
Pen recHoverPen = new Pen(new SolidBrush(Color.FromArgb(82, 218, 163)));
Pen linePen = new Pen(Color.FromArgb(226, 226, 226), 1);
Image icon;
public NewTreeView()
{
InitializeComponent();
this.DrawMode = TreeViewDrawMode.OwnerDrawAll;
this.ItemHeight = 30;//节点行高
this.BackColor = backColor;
this.ShowLines = true;
this.HotTracking = true;
this.Indent = 20;//节点X值缩进量
this.Scrollable = true;
this.BorderStyle = BorderStyle.None;
this.Font = foreFont;
}
protected override void OnDrawNode(DrawTreeNodeEventArgs e)
{
if (e.Node.Level == 0)//根节点
{
if (!e.Node.IsExpanded)//根节点未展开
{
icon = Resources.list_plus;
}
else//根节点展开
{
icon = Resources.list_zhankai;
}
//刷新背景色防止字体图标重绘叠加
e.Graphics.FillRectangle(new SolidBrush(Color.FromArgb(227, 251, 244)), e.Bounds);
//重绘图标，一级节点X值默认为23，padding-left为6,17 = 23 - 6
e.Graphics.DrawImage(icon, e.Node.Bounds.X - 17, e.Node.Bounds.Y + 5);
//重绘字体
e.Graphics.DrawString(e.Node.Text, foreFont, foreBrush, e.Node.Bounds.Left + 16, e.Node.Bounds.Top + 4);
}
else
{
if (!e.Bounds.IsEmpty)//如果子节点的Bounds属性不为空(Empty），绘制该节点
{
e.Graphics.FillRectangle(Brushes.White, e.Bounds);
//绘制连接线,30 = 20 + 10,10为图标宽的一半，保证topEnd点在图标中心，15为行高一半
Point start = new Point(e.Node.Bounds.X + 15, e.Node.Bounds.Y + 15);
Point middle = new Point(e.Node.Bounds.X - 30, e.Node.Bounds.Y + 15);
Point topEnd = new Point(e.Node.Bounds.X - 30, e.Node.Bounds.Y);
Point bottomEnd = new Point(e.Node.Bounds.X - 30, e.Node.Bounds.Y + 30);
e.Graphics.DrawLine(linePen, start, middle);
e.Graphics.DrawLine(linePen, middle, topEnd);
if(null != e.Node.NextNode)
{
e.Graphics.DrawLine(linePen, middle, bottomEnd);
}
//绘制文本框，宽145px可容纳十个10.5pt的字，55 = 23 + 20 + 12，文本框距离上下边界4px
Rectangle box = new Rectangle(e.Bounds.Left + 55, e.Bounds.Top + 4, this.Width - 55 - 25, e.Bounds.Height - 8);
if (e.Node.IsSelected)//二级节点被选中
{
e.Graphics.FillRectangle(recBrush, box);
e.Graphics.DrawString(e.Node.Text, foreFont, recSelectedBrush, e.Node.Bounds.Left + 12, e.Node.Bounds.Top + 4);
}
else
{
if ((e.State & TreeNodeStates.Hot) != 0)//鼠标指针在二级节点上
{
e.Graphics.DrawRectangle(recHoverPen, box);
}
else
{
e.Graphics.DrawRectangle(recPen, box);
}
e.Graphics.DrawString(e.Node.Text, foreFont, foreBrush, e.Node.Bounds.Left + 12, e.Node.Bounds.Top + 4);
}
}
}
}
protected override void OnMouseClick(MouseEventArgs e)
{
base.OnMouseClick(e);
TreeNode tn = this.GetNodeAt(e.Location);
if(0 != tn.Level)//点击一级节点不使二级节点的选中效果消失
{
this.SelectedNode = tn;
}
//图标中心点向右的区域也能单击折叠与展开
Rectangle bounds = new Rectangle(tn.Bounds.Left - 17, tn.Bounds.Y, tn.Bounds.Width - 16, tn.Bounds.Height);
if (tn != null && bounds.Contains(e.Location) == false)
{
if (tn.IsExpanded == false)
tn.Expand();
else
tn.Collapse();
}
}
TreeNode currentNode = null;
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
TreeNode tn = this.GetNodeAt(e.Location);
Graphics g = this.CreateGraphics();
if (currentNode != tn)
{
//绘制当前节点的hover背景
if (null != tn)
{
OnDrawNode(new DrawTreeNodeEventArgs(g, tn, new Rectangle(0, tn.Bounds.Y, this.Width - 4, tn.Bounds.Height), TreeNodeStates.Hot));
}
//取消之前hover的节点背景
if (null != currentNode)
{
OnDrawNode(new DrawTreeNodeEventArgs(g, currentNode, new Rectangle(0, currentNode.Bounds.Y, this.Width - 4, currentNode.Bounds.Height), TreeNodeStates.Default));
}
}
currentNode = tn;
g.Dispose();//释放Graphics资源
}
protected override void OnMouseLeave(EventArgs e)
{
base.OnMouseLeave(e);
//移出控件时取消Hover背景
if (currentNode != null)
{
Graphics g = this.CreateGraphics();
OnDrawNode(new DrawTreeNodeEventArgs(g, currentNode, new Rectangle(0, currentNode.Bounds.Y, this.Width - 4, currentNode.Bounds.Height), TreeNodeStates.Default));
currentNode = null;//同一个节点Leave后Move有Hover效果
}
}
protected override void OnMouseDoubleClick(MouseEventArgs e)
{
base.OnMouseDoubleClick(e);
TreeNode tn = this.GetNodeAt(e.Location);
////图标中心点向右的区域双击折叠与展开
Rectangle bounds = new Rectangle(tn.Bounds.Left - 17, tn.Bounds.Y, tn.Bounds.Width - 16, tn.Bounds.Height);
if (tn != null && bounds.Contains(e.Location) == false)
{
if (tn.IsExpanded == false)
tn.Expand();
else
tn.Collapse();
}
}
}NewTreeView.Designer.cs:
partial class NewTreeView
{
/// <summary>
/// 必需的设计器变量。
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// 清理所有正在使用的资源。
/// </summary>
/// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region 组件设计器生成的代码
/// <summary>
/// 设计器支持所需的方法 - 不要
/// 使用代码编辑器修改此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.SuspendLayout();
//
// NewTreeView
//
this.ResumeLayout(false);
}
#endregion
}