自定义TreeView第三种状态（C#自定义控件）

⾃定义TreeView第三种状态（C#⾃定义控件）
本⽂核⼼部分采⽤此⽹站代码.
在增加了部份事件的同时,将点击图⽚更改节点选中状态这⼀⼩地⽅作了改进.
⽬前点击节点前的加减符号不会更改节点状态.
此处有添加⼀个含有三个图⽚的ImageList 控件,⾥⾯ 0 不选 1 部分选 2 选中三个ICO ⽂件,⼤家可⽹上下载.
using System.Drawing;
using System.Windows.Forms;
namespace SimpleCustomControl
{
public partial class MyTreeView : TreeView
{
private int imageWidth = 0x12;
public MyTreeView()
{
InitializeComponent();
// 如果更改 ImageList 中图⽚⼤⼩,此处设置可能有⽤.未测试.可注释掉.
imageWidth = imageList1.ImageSize.Width + 2;
}
//规则1：取消选定
//规则1.1：检查是否有⼦节点，需清除所有⼦节点的选定状态；
//规则1.2：检查是否有⽗节点，如有，则根据兄弟节点的选定状态修改⽗节点的选定状态
//规则2：选定
//规则2.1：检查是否有⼦节点，设置所有⼦节点为选定状态
//规则2.2：检查是否有⽗节点，如有，则根据兄弟节点的选定状态修改⽗节点的选定状态
///<summary>
///⿏标点击节点触发事件
///</summary>
private void MyTreeView_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
Rectangle rc = e.Node.Bounds;
rc = new Rectangle(rc.X - imageWidth, rc.Y, rc.Width + imageWidth, rc.Height);
if (rc.Contains(e.Location))
{
if (e.Node.Level == 0 && e.Node.Index == 0)
NodeUnSelected();
else
NodeClick(e.Node);
}
}
}
///<summary>
///节点点击
///</summary>
///<param name="tn">点击的节点</param>
public void NodeClick(TreeNode tn)
{
if (tn.ImageIndex == 2)
{
NodeUnSelected(tn);
}
else
{
NodeSelected(tn);
}
}
///<summary>
///不管现在节点状态
///将节点设置为选中
///</summary>
///<param name="tn">待更改状态的节点</param>
public void NodeSelected(TreeNode tn)
{
tn.SelectedImageIndex = 2;
tn.ImageIndex = 2;
SetNodeImg21(tn);
SetNodeImg22(tn);
}
///<summary>
///不管现在节点状态
///去掉节点选中状态
///</summary>
///<param name="tn">待更改状态的节点</param>
public void NodeUnSelected(TreeNode tn)
{
tn.SelectedImageIndex = 0;
tn.ImageIndex = 0;
SetNodeImg11(tn);
SetNodeImg12(tn);
}
///<summary>
///查找节点状态是否被选中
///</summary>
///<param name="tn">查看的节点</param>
///<returns>节点是否被选中</returns>
public bool NodeIsChecked(TreeNode tn)
{
if (tn.ImageIndex == 1 || tn.ImageIndex == 2)
return true;
return false;
}
public CheckState NodeCheckState(TreeNode tn)
{
switch (tn.ImageIndex)
{
case1:
return CheckState.Indeterminate;
case2:
return CheckState.Checked;
case0:
default:
return CheckState.Unchecked;
}
}
///<summary>
///将所有⼦节点全不选
///</summary>
public void NodeUnSelected()
{
foreach (TreeNode tn in this.Nodes)
{
NodeUnSelected(tn);
}
}
///<summary>
///将所有⼦节点全选
///</summary>
public void NodeSelected()
{
foreach (TreeNode tn in this.Nodes)
{
NodeSelected(tn);
}
}
//设置节点选定状态：
//规则.1：检查是否有⼦节点，需清除所有⼦节点的选定状态；
void SetNodeImg11(TreeNode tn)
{
foreach (TreeNode t in tn.Nodes)
{
t.SelectedImageIndex = 0;
t.ImageIndex = 0;
if (t.Nodes.Count != 0)
SetNodeImg11(t);
}
}
//设置节点选定状态：
//规则.2：检查是否有⽗节点，如有，则根据兄弟节点的选定状态修改⽗节点的选定状态void SetNodeImg12(TreeNode tn)
{
if (tn.Parent == null)
return;
int Img0Num = 0, Img1Num = 0, Img2Num = 0;
//统计同级节点选中情况
foreach (TreeNode t in tn.Parent.Nodes)
{
switch (t.ImageIndex)
{
case1:
Img1Num++;
break;
case2:
Img2Num++;
break;
case0:
default:
Img0Num++;
break;
}
}
//如果同级节点选中和未选中的都有
if (Img1Num != 0 || (Img0Num != 0 && Img2Num != 0))
{
tn.Parent.SelectedImageIndex = 1;
tn.Parent.ImageIndex = 1;
}
else
{
tn.Parent.StateImageIndex = 0;
tn.Parent.ImageIndex = 0;
}
SetNodeImg12(tn.Parent);
}
//设置节点选定状态：
//规则.1：检查是否有⼦节点，设置所有⼦节点为选定状态
void SetNodeImg21(TreeNode tn)
{
foreach (TreeNode t in tn.Nodes)
{
t.SelectedImageIndex = 2;
t.ImageIndex = 2;
if (t.Nodes.Count != 0)
{
SetNodeImg21(t);
}
}
}
//设置节点选定状态：
//规则.2：检查是否有⽗节点，如有，则根据兄弟节点的选定状态修改⽗节点的选定状态void SetNodeImg22(TreeNode tn)
{
if (tn.Parent == null)
return;
int Img0Num = 0, Img1Num = 0, Img2Num = 0;
foreach (TreeNode t in tn.Parent.Nodes)
{
//if (t.ImageIndex == 0)
// Img0Num++;
//if (t.ImageIndex == 1)
// Img1Num++;
//if (t.ImageIndex == 2)
// Img2Num++;
switch (t.ImageIndex)
{
case1:
Img1Num++;
break;
case2:
Img2Num++;
break;
case0:
default:
Img0Num++;
break;
}
}
if (Img1Num != 0 || (Img0Num != 0 && Img2Num != 0))
{
tn.Parent.SelectedImageIndex = 1;
tn.Parent.ImageIndex = 1;
}
//else if (Img1Num == 0 && Img2Num == 0)
//{
// tn.Parent.SelectedImageIndex = 0;
// tn.Parent.ImageIndex = 0;
//}
else
{
tn.Parent.StateImageIndex = 2;
tn.Parent.ImageIndex = 2;
}
SetNodeImg22(tn.Parent); }
}
}。