C# DataGridView 带Tree 功能

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;


namespace TestDataGridViewRowStyle
{
    public partial class Form1 : Form
    {
        //定义两种行样式
        private DataGridViewCellStyle m_RowStyleNormal;
        private DataGridViewCellStyle m_RowStyleAlternate;

        //成绩单DataTable
        private DataTable m_GradeTable;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.dgvGrade.AutoGenerateColumns = false;
            this.SetRowStyle();
            this.BindData();
        }

        /// <summary>
        /// 设置行样式
        /// </summary>
        private void SetRowStyle()
        {
            //可根据需要设置更多样式属性，如字体、对齐、前景色、背景色等
            this.m_RowStyleNormal = new DataGridViewCellStyle();
            this.m_RowStyleNormal.BackColor = Color.LightBlue;
            this.m_RowStyleNormal.SelectionBackColor = Color.LightSteelBlue;

            this.m_RowStyleAlternate = new DataGridViewCellStyle();
            this.m_RowStyleAlternate.BackColor = Color.LightGray;
            this.m_RowStyleAlternate.SelectionBackColor = Color.LightSlateGray;
        }

        /// <summary>
        /// 绑定数据
        /// </summary>
        private void BindData()
        {
            //建立一个DataTable并填充数据，然后绑定到DataGridView控件上
            m_GradeTable = new DataTable();
            m_GradeTable.Columns.Add("Class", typeof(string));
            m_GradeTable.Columns.Add("Name", typeof(string));
            m_GradeTable.Columns.Add("Grade", typeof(int));
            m_GradeTable.Columns.Add("Parent", typeof(string));
            m_GradeTable.Rows.Add(new string[] { "X001", "Jim", "89","" });
            m_GradeTable.Rows.Add(new string[] { "X002", "Jack", "77", "X001" });
            m_GradeTable.Rows.Add(new string[] { "X003", "Bill", "91", "X001" });
            m_GradeTable.Rows.Add(new string[] { "X004", "Tom", "58", "" });
            m_GradeTable.Rows.Add(new string[] { "X005", "Rose", "95", "X004" });
            m_GradeTable.Rows.Add(new string[] { "X006", "Peter", "64", "X004" });
            m_GradeTable.Rows.Add(new string[] { "X007", "David", "82", "X004" });
            m_GradeTable.Rows.Add(new string[] { "X008", "Eric", "68", "" });
            m_GradeTable.Rows.Add(new string[] { "X008", "Lily", "79", "X008" });
            this.bdsGrade.DataSource = m_GradeTable;       
        }

        private void dgvDataTable_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
        {
            //在此对行样式进行设置

            //if (e.ColumnIndex == this.dgvGrade.Columns["ColumnClass"].Index)//根据班级设置行样式
            //{
            //    DataGridViewRow CurrentRow = this.dgvGrade.Rows[e.RowIndex];
            //    CurrentRow.HeaderCell.Value = Convert.ToString(e.RowIndex + 1);//显示行号，也可以设置成显示其他信息
            //    //CurrentRow.HeaderCell.ToolTipText = "当前第" + Convert.ToString(e.RowIndex + 1) + "行";//设置ToolTip信息

            //    //以下为根据上一行内容判断所属组的效果
            //    if (e.RowIndex == 0)//首行必须特殊处理，将其设置为常规样式
            //    {
            //        CurrentRow.DefaultCellStyle = this.m_RowStyleNormal;
            //    }
            //    else
            //    {
            //        //判断和上一行是否属于同一个班级，如果是则设置相同样式，否则设置另一种样式
            //        //需要定义两个DataGridViewCellStyle，用于交替显示，也可以根据需要隐藏一些和上一行重复的信息
            //        //这里当两行是同一个班级时，将下一行的班级信息隐藏掉，选中时则显示班级信息
                      
            //        if (CurrentRow.Cells[e.ColumnIndex].Value != DBNull.Value && CurrentRow.Cells[e.ColumnIndex].Value != null
            //            && CurrentRow.Cells[e.ColumnIndex].Value.ToString() == this.dgvGrade.Rows[e.RowIndex - 1].Cells[e.ColumnIndex].Value.ToString())
            //        {
            //            CurrentRow.DefaultCellStyle = this.dgvGrade.Rows[e.RowIndex - 1].DefaultCellStyle;//设置和上一行的样式相同
            //            CurrentRow.Cells[e.ColumnIndex].Style.ForeColor = CurrentRow.DefaultCellStyle.BackColor;//用前景色隐藏信息
            //            //如果需要选中时显示完整信息则注释该下面一行
            //            CurrentRow.Cells[e.ColumnIndex].Style.SelectionForeColor = CurrentRow.DefaultCellStyle.SelectionBackColor;//选中时也使前景色等于背景色，将文字隐藏掉
            //        }
            //        else//当前行和上一行不属于同一个班级时
            //        {
            //            if (this.dgvGrade.Rows[e.RowIndex - 1].DefaultCellStyle == this.m_RowStyleNormal)//根据上一行的样式设置当前行的样式
            //                CurrentRow.DefaultCellStyle = this.m_RowStyleAlternate;
            //            else
            //                CurrentRow.DefaultCellStyle = this.m_RowStyleNormal;
            //        }
            //    }//if(e.RowIndex == 0)
            //}
            //else if (e.ColumnIndex == this.dgvGrade.Columns["ColumnGrade"].Index)//根据成绩设置单元格样式
            //{
            //    if (this.dgvGrade.Rows[e.RowIndex].Cells[e.ColumnIndex].Value != DBNull.Value 
            //        && Convert.ToInt32(this.dgvGrade.Rows[e.RowIndex].Cells[e.ColumnIndex].Value) < 60)//对不及格的成绩设置特殊样式
            //    {
            //        this.dgvGrade.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.ForeColor = Color.Red;//设置小于60的数字显示为红色
            //        this.dgvGrade.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.SelectionForeColor = Color.Red;
            //        this.dgvGrade.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.Alignment = DataGridViewContentAlignment.MiddleRight;
            //    }
            //}

                if (e.ColumnIndex == this.dgvGrade.Columns["ColumnClass"].Index)
                {
                    DataGridViewRow CurrentRow = this.dgvGrade.Rows[e.RowIndex];
                    if (e.RowIndex == 0)//首行必须特殊处理，将其设置为常规样式
                    {
                        CurrentRow.DefaultCellStyle = this.m_RowStyleNormal;
                    }
                    else
                    {
                        int Pi = this.dgvGrade.Columns["ColumnParent"].Index;

                        if (CurrentRow.Cells[e.ColumnIndex].Value != DBNull.Value && CurrentRow.Cells[e.ColumnIndex].Value != null
                            && ParentNode(CurrentRow.Cells[Pi].Value.ToString(), e.RowIndex))//CurrentRow.Cells[Pi].Value.ToString() == this.dgvGrade.Rows[e.RowIndex - 1].Cells[e.ColumnIndex].Value.ToString()
                        {
                            CurrentRow.DefaultCellStyle = this.dgvGrade.Rows[e.RowIndex - 1].DefaultCellStyle;//设置和上一行的样式相同
                            this.dgvGrade.Rows[e.RowIndex].Cells[e.ColumnIndex].Style.Alignment =  DataGridViewContentAlignment.MiddleCenter;
                           // CurrentRow.Cells[e.ColumnIndex].Style.ForeColor = CurrentRow.DefaultCellStyle.BackColor;//用前景色隐藏信息
                            //如果需要选中时显示完整信息则注释该下面一行
                          //  CurrentRow.Cells[e.ColumnIndex].Style.SelectionForeColor = CurrentRow.DefaultCellStyle.SelectionBackColor;//选中时也使前景色等于背景色，将文字隐藏掉
                        }
                        else//当前行和上一行不属于同一个班级时
                        {
                            if (this.dgvGrade.Rows[e.RowIndex - 1].DefaultCellStyle == this.m_RowStyleNormal)//根据上一行的样式设置当前行的样式
                                CurrentRow.DefaultCellStyle = this.m_RowStyleAlternate;
                            else
                                CurrentRow.DefaultCellStyle = this.m_RowStyleNormal;
                        }
                    }
                }           

        }

        //根据内容设置行标头
        private void dgvDataTable_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
        {
            if (this.dgvGrade.Rows[e.RowIndex].Cells["ColumnGrade"].Value == DBNull.Value)
                return;

            int intGrade = Convert.ToInt32(this.dgvGrade.Rows[e.RowIndex].Cells["ColumnGrade"].Value);//获取成绩
            Image RowIcon;//标头图标
            string strToolTip;//提示信息

            if (intGrade >= 90)
            {
                RowIcon = TestDataGridViewRowStyle.Properties.Resources.GradeA;//从资源文件中获取图片
                strToolTip = "Grade A";
            }
            else if (intGrade >= 80)
            {
                RowIcon = TestDataGridViewRowStyle.Properties.Resources.GradeB;
                strToolTip = "Grade B";
            }
            else if (intGrade >= 70)
            {
                RowIcon = TestDataGridViewRowStyle.Properties.Resources.GradeC;
                strToolTip = "Grade C";
            }
            else if (intGrade >= 60)
            {
                RowIcon = TestDataGridViewRowStyle.Properties.Resources.GradeD;
                strToolTip = "Grade D";
            }
            else
            {
                RowIcon = TestDataGridViewRowStyle.Properties.Resources.GradeF;
                strToolTip = "Grade F";
            }

            e.Graphics.DrawImage(RowIcon, e.RowBounds.Left + this.dgvGrade.RowHeadersWidth - 20, e.RowBounds.Top + 4, 16, 16);//绘制图标
            this.dgvGrade.Rows[e.RowIndex].HeaderCell.ToolTipText = strToolTip;//设置提示信息

        }

        private void dgvGrade_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
        {
            if (e.ColumnIndex == -1 && e.RowIndex == -1)
            {
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, Color.LightGray,
                    Color.White, LinearGradientMode.ForwardDiagonal))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    e.Graphics.DrawRectangle(Pens.Gray, border);
                }
                e.PaintContent(e.CellBounds);
                e.Handled = true;
            }
            else if (e.RowIndex == -1)
            {
                //标题行
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, Color.LightGray,
                    Color.White, LinearGradientMode.Vertical))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    e.Graphics.DrawRectangle(Pens.Gray, border);
                }
                e.PaintContent(e.CellBounds);
                e.Handled = true;
            }
            else if (e.ColumnIndex == -1)
            {
                //标题列
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, Color.LightGray,
                    Color.White, LinearGradientMode.Horizontal))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    e.Graphics.DrawRectangle(Pens.Gray, border);
                }
                e.PaintContent(e.CellBounds);
                e.Handled = true;
            }

            //if (e.RowIndex > -1 && e.ColumnIndex > -1)
            //{
            //    e.PaintBackground(e.CellBounds, false);
            //    e.Graphics.FillEllipse(Brushes.Red, e.CellBounds);
            //    e.Graphics.DrawString(e.RowIndex.ToString() + e.ColumnIndex.ToString(), this.Font, Brushes.Black, new PointF(e.CellBounds.X + 8, e.CellBounds.Y + 8));
            //    e.Handled = true;
            //}



        }

        private bool ParentNode(string ChidStr,int index)
        {
            for (int i = 0; i < index; i++)
            {
                if (this.dgvGrade.Rows[i].Cells[0].Value.ToString() == ChidStr)
                {
                    return true;
                }
            }
            return false;
           
        }
                    

    }
}