在 WinForms 中，想要实现多层表头功能时，DataGridView 本身并不支持该功能，而且又不希望使用第三方控件，因此选择通过自定义组件来实现这一需求。
首先，展示一下程序实现的效果：
接下来，创建一个继承自 DataGridView 的自定义组件。代码如下：
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Windows.Forms;
using System.Collections;
using System.Drawing;namespace CellPaintingDataGridView
{public partial class TreeHeadDataGridView : DataGridView{private TreeView treeView1=new TreeView();public TreeHeadDataGridView(){InitializeComponent();}public TreeHeadDataGridView(IContainer container){container.Add(this);InitializeComponent();}[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]public TreeNodeCollection HeadSource{get { return this.treeView1.Nodes; }}private int _cellHeight = 17;private int _columnDeep = 1;[Description("设置或获得合并表头树的深度")]public int ColumnDeep{get{if (this.Columns.Count == 0)_columnDeep = 1;this.ColumnHeadersHeight = _cellHeight * _columnDeep;return _columnDeep;}set{if (value < 1)_columnDeep = 1;else_columnDeep = value;this.ColumnHeadersHeight = _cellHeight * _columnDeep;}}///<summary>///绘制合并表头///</summary>///<param name="node">合并表头节点</param>///<param name="e">绘图参数集</param>///<param name="level">结点深度</param>///<remarks></remarks>public void PaintUnitHeader(TreeNode node, DataGridViewCellPaintingEventArgs e, int level){//根节点时退出递归调用if (level == 0)return;RectangleF uhRectangle;int uhWidth;SolidBrush gridBrush = new SolidBrush(this.GridColor);Pen gridLinePen = new Pen(gridBrush);StringFormat textFormat = new StringFormat();textFormat.Alignment = StringAlignment.Center;uhWidth = GetUnitHeaderWidth(node);//与原贴算法有所区别在这。if (node.Nodes.Count == 0){uhRectangle = new Rectangle(e.CellBounds.Left,e.CellBounds.Top + node.Level * _cellHeight,uhWidth - 1,_cellHeight * (_columnDeep - node.Level) - 1);}else{uhRectangle = new Rectangle(e.CellBounds.Left,e.CellBounds.Top + node.Level * _cellHeight,uhWidth - 1,_cellHeight - 1);}Color backColor = e.CellStyle.BackColor;if (node.BackColor != Color.Empty){backColor = node.BackColor;}SolidBrush backColorBrush = new SolidBrush(backColor);//画矩形e.Graphics.FillRectangle(backColorBrush, uhRectangle);//划底线e.Graphics.DrawLine(gridLinePen, uhRectangle.Left, uhRectangle.Bottom, uhRectangle.Right, uhRectangle.Bottom);//划右端线e.Graphics.DrawLine(gridLinePen, uhRectangle.Right, uhRectangle.Top, uhRectangle.Right, uhRectangle.Bottom);写字段文本Color foreColor = Color.Black;if (node.ForeColor != Color.Empty){foreColor = node.ForeColor;}e.Graphics.DrawString(node.Text, this.Font, new SolidBrush(foreColor), uhRectangle.Left + uhRectangle.Width / 2 -e.Graphics.MeasureString(node.Text, this.Font).Width / 2 - 1, uhRectangle.Top +uhRectangle.Height / 2 - e.Graphics.MeasureString(node.Text, this.Font).Height / 2);递归调用()if (node.PrevNode == null)if (node.Parent != null)PaintUnitHeader(node.Parent, e, level - 1);}/// <summary>/// 获得合并标题字段的宽度/// </summary>/// <param name="node">字段节点</param>/// <returns>字段宽度</returns>/// <remarks></remarks>private int GetUnitHeaderWidth(TreeNode node){//获得非最底层字段的宽度int uhWidth = 0;//获得最底层字段的宽度if (node.Nodes == null)return this.Columns[GetColumnListNodeIndex(node)].Width;if (node.Nodes.Count == 0)return this.Columns[GetColumnListNodeIndex(node)].Width;for (int i = 0; i <= node.Nodes.Count - 1; i++){uhWidth = uhWidth + GetUnitHeaderWidth(node.Nodes[i]);}return uhWidth;}/// <summary>/// 获得底层字段索引/// </summary>/// <param name="node">底层字段节点</param>/// <returns>索引</returns>/// <remarks></remarks>private int GetColumnListNodeIndex(TreeNode node){for (int i = 0; i <= _columnList.Count - 1; i++){if (((TreeNode)_columnList[i]).Equals(node))return i;}return -1;}private List<TreeNode> _columnList = new List<TreeNode>();[Description("最底層結點集合")]public List<TreeNode> NadirColumnList{get{if (this.treeView1 == null)return null;if (this.treeView1.Nodes == null)return null;if (this.treeView1.Nodes.Count == 0)return null;_columnList.Clear();foreach (TreeNode node in this.treeView1.Nodes){//GetNadirColumnNodes(_columnList, node, false);GetNadirColumnNodes(_columnList, node);}return _columnList;}}private void GetNadirColumnNodes(List<TreeNode> alList, TreeNode node){if (node.FirstNode == null){alList.Add(node);}foreach (TreeNode n in node.Nodes){GetNadirColumnNodes(alList, n);}}/// <summary>/// 获得底层字段集合/// </summary>/// <param name="alList">底层字段集合</param>/// <param name="node">字段节点</param>/// <param name="checked">向上搜索与否</param>/// <remarks></remarks>private void GetNadirColumnNodes(List<TreeNode> alList, TreeNode node, Boolean isChecked){if (isChecked == false){if (node.FirstNode == null){alList.Add(node);if (node.NextNode != null){GetNadirColumnNodes(alList, node.NextNode, false);return;}if (node.Parent != null){GetNadirColumnNodes(alList, node.Parent, true);return;}}else{if (node.FirstNode != null){GetNadirColumnNodes(alList, node.FirstNode, false);return;}}}else{if (node.FirstNode == null){return;}else{if (node.NextNode != null){GetNadirColumnNodes(alList, node.NextNode, false);return;}if (node.Parent != null){GetNadirColumnNodes(alList, node.Parent, true);return;}}}}/// <summary>/// 单元格绘制(重写)/// </summary>/// <param name="e"></param>/// <remarks></remarks>protected override void OnCellPainting(DataGridViewCellPaintingEventArgs e){//行标题不重写if (e.ColumnIndex < 0){base.OnCellPainting(e);return;}if (_columnDeep == 1){base.OnCellPainting(e);return;}//绘制表头if (e.RowIndex == -1){PaintUnitHeader((TreeNode)NadirColumnList[e.ColumnIndex], e, _columnDeep);e.Handled = true;}}}
}完成组件开发后，可以将该控件从工具箱拖入界面，表头的节点设置通过 Designer.cs 中的 "Windows 窗体设计器生成的代码" 实现。我们使用 System.Windows.Forms.TreeNode 来实现父子节点的绑定。示例代码如下：
namespace CellPaintingDataGridView
{partial class Form1{/// <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 Windows 窗体设计器生成的代码/// <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.components = new System.ComponentModel.Container();System.Windows.Forms.TreeNode treeNode1 = new System.Windows.Forms.TreeNode("节点0");System.Windows.Forms.TreeNode treeNode2 = new System.Windows.Forms.TreeNode("节点1-0-0");System.Windows.Forms.TreeNode treeNode3 = new System.Windows.Forms.TreeNode("节点1-0-1");System.Windows.Forms.TreeNode treeNode4 = new System.Windows.Forms.TreeNode("节点1-0", new System.Windows.Forms.TreeNode[] {treeNode2,treeNode3});System.Windows.Forms.TreeNode treeNode5 = new System.Windows.Forms.TreeNode("节点1-1");System.Windows.Forms.TreeNode treeNode6 = new System.Windows.Forms.TreeNode("节点1", new System.Windows.Forms.TreeNode[] {treeNode4,treeNode5});System.Windows.Forms.TreeNode treeNode7 = new System.Windows.Forms.TreeNode("节点2-0");System.Windows.Forms.TreeNode treeNode8 = new System.Windows.Forms.TreeNode("节点2-1");System.Windows.Forms.TreeNode treeNode9 = new System.Windows.Forms.TreeNode("节点2-0");System.Windows.Forms.TreeNode treeNode10 = new System.Windows.Forms.TreeNode("节点2", new System.Windows.Forms.TreeNode[] {treeNode7,treeNode8,treeNode9});System.Windows.Forms.TreeNode treeNode11 = new System.Windows.Forms.TreeNode("节点3-0");System.Windows.Forms.TreeNode treeNode12 = new System.Windows.Forms.TreeNode("节点3-1");System.Windows.Forms.TreeNode treeNode13 = new System.Windows.Forms.TreeNode("节点3", new System.Windows.Forms.TreeNode[] {treeNode11,treeNode12});this.treeHeadDataGridView1 = new CellPaintingDataGridView.TreeHeadDataGridView(this.components);this.Column1 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column2 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column3 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column4 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column5 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column6 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column7 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column8 = new System.Windows.Forms.DataGridViewTextBoxColumn();this.Column9 = new System.Windows.Forms.DataGridViewTextBoxColumn();((System.ComponentModel.ISupportInitialize)(this.treeHeadDataGridView1)).BeginInit();this.SuspendLayout();// // treeHeadDataGridView1// this.treeHeadDataGridView1.ColumnDeep = 3;this.treeHeadDataGridView1.ColumnHeadersHeight = 51;this.treeHeadDataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.DisableResizing;this.treeHeadDataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {this.Column1,this.Column2,this.Column3,this.Column4,this.Column5,this.Column6,this.Column7,this.Column8,this.Column9});treeNode1.Name = "节点";treeNode1.Text = "节点0";treeNode2.Name = "节点1-0-0";treeNode2.Text = "节点1-0-0";treeNode3.Name = "节点1-0-1";treeNode3.Text = "节点1-0-1";treeNode4.Name = "节点1-0";treeNode4.Text = "节点1-0";treeNode5.Name = "节点1-1";treeNode5.Text = "节点1-1";treeNode6.Name = "节点1";treeNode6.Text = "节点1";treeNode7.Name = "节点2-0";treeNode7.Text = "节点2-0";treeNode8.Name = "节点2-1";treeNode8.Text = "节点2-1";treeNode9.Name = "节点2-0";treeNode9.Text = "节点2-0";treeNode10.Name = "节点2";treeNode10.Text = "节点2";treeNode11.Name = "节点3-0";treeNode11.Text = "节点3-0";treeNode12.Name = "节点3-1";treeNode12.Text = "节点3-1";treeNode13.Name = "节点3";treeNode13.Text = "节点3";this.treeHeadDataGridView1.HeadSource.AddRange(new System.Windows.Forms.TreeNode[] {treeNode1,treeNode6,treeNode10,treeNode13});this.treeHeadDataGridView1.Location = new System.Drawing.Point(12, 12);this.treeHeadDataGridView1.Name = "treeHeadDataGridView1";this.treeHeadDataGridView1.RowTemplate.Height = 23;this.treeHeadDataGridView1.Size = new System.Drawing.Size(1034, 456);this.treeHeadDataGridView1.TabIndex = 0;// // Column1// this.Column1.HeaderText = "Column1";this.Column1.Name = "Column1";this.Column1.Width = 110;// // Column2// this.Column2.FillWeight = 80F;this.Column2.HeaderText = "Column2";this.Column2.Name = "Column2";// // Column3// this.Column3.FillWeight = 60F;this.Column3.HeaderText = "Column3";this.Column3.Name = "Column3";this.Column3.Width = 160;// // Column4// this.Column4.HeaderText = "Column4";this.Column4.Name = "Column4";// // Column5// this.Column5.HeaderText = "Column5";this.Column5.Name = "Column5";// // Column6// this.Column6.HeaderText = "Column6";this.Column6.Name = "Column6";// // Column7// this.Column7.HeaderText = "Column7";this.Column7.Name = "Column7";// // Column8// this.Column8.HeaderText = "Column8";this.Column8.Name = "Column8";// // Column9// this.Column9.HeaderText = "Column9";this.Column9.Name = "Column9";// // Form1// this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;this.ClientSize = new System.Drawing.Size(1077, 533);this.Controls.Add(this.treeHeadDataGridView1);this.Name = "Form1";this.Text = "Form1";((System.ComponentModel.ISupportInitialize)(this.treeHeadDataGridView1)).EndInit();this.ResumeLayout(false);}#endregionprivate TreeHeadDataGridView treeHeadDataGridView1;private System.Windows.Forms.DataGridViewTextBoxColumn Column1;private System.Windows.Forms.DataGridViewTextBoxColumn Column2;private System.Windows.Forms.DataGridViewTextBoxColumn Column3;private System.Windows.Forms.DataGridViewTextBoxColumn Column4;private System.Windows.Forms.DataGridViewTextBoxColumn Column5;private System.Windows.Forms.DataGridViewTextBoxColumn Column6;private System.Windows.Forms.DataGridViewTextBoxColumn Column7;private System.Windows.Forms.DataGridViewTextBoxColumn Column8;private System.Windows.Forms.DataGridViewTextBoxColumn Column9;}
}通过这种方式，我们成功实现了多层表头的功能，完全依赖自定义组件，不需要第三方控件。
源码地址：https://download.csdn.net/download/weixin_44643352/90054291?spm=1001.2014.3001.5503
