場景

DevExpress的TreeList怎樣設置數據源使其顯示成單列樹形結構：

https://blog.csdn.net/BADAO_LIUMANG_QIZHI/article/details/102742426

在上面設置TreeList的數據源並設置其為樹形結構後，如何給樹形結構設置圖標

註：

博客主頁：
https://blog.csdn.net/badao_liumang_qizhi
關註公眾號
霸道的程式猿
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實現

首先按照上面搭建好樹形結構和設置數據源之後效果如下

然後在項目下新建Resources目錄，將圖標文件複製進去

然後在窗體類中獲取圖標數組

 public static System.Drawing.Image[] imgs = new System.Drawing.Image[] { 
            System.Drawing.Image.FromFile(@"../../Resources/a.png"),
            System.Drawing.Image.FromFile(@"../../Resources/b.png"),
            System.Drawing.Image.FromFile(@"../../Resources/c.png")
        };

這裡路徑為什麼是兩層上級目錄，因為Resources目錄相對應bin/debug的目錄如此

然後在窗體載入完的事件中對TreeList設置完數據源之後，設置每個節點的圖標。

System.Windows.Forms.ImageList imgList = new System.Windows.Forms.ImageList();
imgList.Images.AddRange(imgs);
treeList1.SelectImageList = imgList;
treeList1.Nodes.FirstOrDefault().ImageIndex = 0;
treeList1.Nodes.FirstOrDefault().FirstNode.ImageIndex = 1;
treeList1.Nodes.FirstOrDefault().FirstNode.FirstNode.ImageIndex = 2;

這裡是通過treeList1.Nodes.FirstOrDefault()找到第一個節點或者預設節點，即根節點。

然後通過FirstNode找到第一個子節點。

然後treeList1.SelectImageList = imgList設置其圖標源是一個圖標數組。

然後指定每個節點的ImageIndex 就是在圖標數組中的索引。

完整示例代碼：

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 TreeListTest
{
    public partial class Form1 : Form
    {
       
        public static System.Drawing.Image[] imgs = new System.Drawing.Image[] { 
            System.Drawing.Image.FromFile(@"../../Resources/a.png"),
            System.Drawing.Image.FromFile(@"../../Resources/b.png"),
            System.Drawing.Image.FromFile(@"../../Resources/c.png")
        };

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

           
            #region 設置列頭、節點指示器面板、表格線樣式

            treeList1.OptionsView.ShowColumns = false;             //隱藏列標頭
            treeList1.OptionsView.ShowIndicator = false;           //隱藏節點指示器面板
            treeList1.OptionsView.ShowHorzLines = false;           //隱藏水平表格線
            treeList1.OptionsView.ShowVertLines = false;           //隱藏垂直表格線
            treeList1.OptionsView.ShowIndentAsRowStyle = false;

            #endregion

            #region 初始禁用單元格選中，禁用整行選中

            treeList1.OptionsView.ShowFocusedFrame = true;                               //設置顯示焦點框
            treeList1.OptionsSelection.EnableAppearanceFocusedCell = false;              //禁用單元格選中
            treeList1.OptionsSelection.EnableAppearanceFocusedRow = false;               //禁用正行選中

            #endregion

            #region 設置TreeList的展開摺疊按鈕樣式和樹線樣式

            treeList1.OptionsView.ShowButtons = true;                  //顯示展開摺疊按鈕
            treeList1.LookAndFeel.UseDefaultLookAndFeel = false;       //禁用預設外觀與感覺
            treeList1.LookAndFeel.UseWindowsXPTheme = true;            //使用WindowsXP主題
            treeList1.TreeLineStyle = DevExpress.XtraTreeList.LineStyle.Percent50;     //設置樹線的樣式

            #endregion

            #region 添加單列

            DevExpress.XtraTreeList.Columns.TreeListColumn colNode = new DevExpress.XtraTreeList.Columns.TreeListColumn();
            colNode.Name = String.Format("col{0}", "NodeText");
            colNode.Caption = "NodeText";
            colNode.FieldName = "NodeText";
            colNode.VisibleIndex = 0;
            colNode.Visible = true;

            colNode.OptionsColumn.AllowEdit = false;                        //是否允許編輯
            colNode.OptionsColumn.AllowMove = false;                        //是否允許移動
            colNode.OptionsColumn.AllowMoveToCustomizationForm = false;     //是否允許移動至自定義窗體
            colNode.OptionsColumn.AllowSort = false;                        //是否允許排序
            colNode.OptionsColumn.FixedWidth = false;                       //是否固定列寬
            colNode.OptionsColumn.ReadOnly = true;                          //是否只讀
            colNode.OptionsColumn.ShowInCustomizationForm = true;           //移除列後是否允許在自定義窗體中顯示

            treeList1.Columns.Clear();
            treeList1.Columns.AddRange(new DevExpress.XtraTreeList.Columns.TreeListColumn[] { colNode });

            #endregion

            treeList1.KeyFieldName = "Id";
            treeList1.ParentFieldName = "ParentId";

            DataTreeNode node1 = new DataTreeNode();
            node1.Id = "1";
            node1.ParentId = null;
            node1.NodeText = "1公眾號";

            DataTreeNode node11 = new DataTreeNode();
            node11.Id = "2";
            node11.ParentId = "1";
            node11.NodeText = "1-1霸道的程式猿";

            DataTreeNode node111 = new DataTreeNode();
            node111.Id = "3";
            node111.ParentId = "2";
            node111.NodeText = "1-1-1大量編程資源";


            List<DataTreeNode> data = new List<DataTreeNode>();

            data.Add(node1);
            data.Add(node11);
            data.Add(node111);
            
            treeList1.DataSource = data;
            treeList1.RefreshDataSource();

            System.Windows.Forms.ImageList imgList = new System.Windows.Forms.ImageList();
            imgList.Images.AddRange(imgs);

            treeList1.SelectImageList = imgList;

          
            
            treeList1.Nodes.FirstOrDefault().ImageIndex = 0;
            treeList1.Nodes.FirstOrDefault().FirstNode.ImageIndex = 1;
            treeList1.Nodes.FirstOrDefault().FirstNode.FirstNode.ImageIndex = 2;
        }
    }
}