using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace TreeView的使用
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            MessageBox.Show(treeView1.SelectedNode.Text);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            //Nodes是第一级节点的集合，在第一级节点添加，即根节点
            //treeView1.Nodes.Add()
            //在第一个根节点的下一级添加
            //treeView1.Nodes[0].Nodes.Add("aaa");

            //根据用户选择添加信息
            if(treeView1.SelectedNode != null)
            {
                treeView1.SelectedNode.Nodes.Add(textBox1.Text);
            }
            else
            {
                treeView1.Nodes.Add(textBox1.Text);
            }

        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //展开所有节点
            treeView1.ExpandAll();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            treeView1.CollapseAll();
        }

        private void button4_Click(object sender, EventArgs e)
        {
            treeView1.ExpandAll();
        }

        private void button5_Click(object sender, EventArgs e)
        {

            treeView1.SelectedNode.Collapse();
        }

        private void button6_Click(object sender, EventArgs e)
        {
            //当前节点的的下一级节点
            treeView1.SelectedNode.Expand();

            //当前节点的所有节点
            //treeView1.SelectedNode.ExpandAll();
        }

        private void button7_Click(object sender, EventArgs e)
        {
            treeView1.SelectedNode.Remove();
        }

        private void button8_Click(object sender, EventArgs e)
        {
            treeView1.SelectedNode.Text = textBox2.Text;
        }

        private void button9_Click(object sender, EventArgs e)
        {
            string str = "选中的节点：\n";
            foreach(TreeNode tn in treeView1.Nodes[0].Nodes[0].Nodes)
            {
                if(tn.Checked)
                    str += tn.Text+"\n";
            }

            MessageBox.Show(str);
        }

        private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
        {

        }

        private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
        {
            foreach(TreeNode tn in e.Node.Nodes)
            {
                tn.Checked = e.Node.Checked;
            }
        }
    }
}