DevExpress GridControl 用路径加载图片，插入到Grid列中



要实现该功能，可通过非绑定列的方式来实现。具体实现方法如下：

1.创建了一个非绑定列并设置其相应的属性，属性设置如下：

FieldName设为 Image (该字段名必须是唯一的)

UnboundType设为 UnboundColumnType.Object

ColumnEdit设为RepositoryItemPictureEdit类的实例(该操作PictureEdit 为该列的内置编辑器)

2. 处理View的CustomUnboundColumnData事件，用于为非绑定列填充数据。在该事件中需加载图片，将其存放在一个hashtable中，然后再将其提供给对应的单元格。

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

using DevExpress.XtraGrid.Views.Grid;

namespace LoadExternalImages {
    /// 

    /// Summary description for Form1.
    /// 
    public class Form1 : System.Windows.Forms.Form {
      private DevExpress.XtraGrid.GridControl gridControl1;
      private DevExpress.XtraGrid.Views.Grid.GridView gridView1;
      private System.Windows.Forms.Label label1;
      private DevExpress.XtraGrid.Columns.GridColumn columnID;
      private DevExpress.XtraGrid.Columns.GridColumn columnName;
      private DevExpress.XtraGrid.Columns.GridColumn columnColor;
      private DevExpress.XtraGrid.Columns.GridColumn columnImage;
      private DevExpress.XtraEditors.Repository.RepositoryItemPictureEdit repositoryItemPictureEdit1;
      private DevExpress.XtraEditors.Repository.RepositoryItemComboBox repositoryItemComboBox1;
        /// 

        /// Required designer variable.
        /// 
        private System.ComponentModel.Container components = null;

        public Form1()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();

            //
            // TODO: Add any constructor code after InitializeComponent call
            //
         InitData();
        }

        /// 

        /// Clean up any resources being used.
        /// 
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        #region Windows Form Designer generated code
        /// 

        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// 
        private void InitializeComponent()
        {
            this.gridControl1 = new DevExpress.XtraGrid.GridControl();
            this.gridView1 = new DevExpress.XtraGrid.Views.Grid.GridView();
            this.columnID = new DevExpress.XtraGrid.Columns.GridColumn();
            this.columnName = new DevExpress.XtraGrid.Columns.GridColumn();
            this.columnColor = new DevExpress.XtraGrid.Columns.GridColumn();
            this.repositoryItemComboBox1 = new DevExpress.XtraEditors.Repository.RepositoryItemComboBox();
            this.columnImage = new DevExpress.XtraGrid.Columns.GridColumn();
            this.repositoryItemPictureEdit1 = new DevExpress.XtraEditors.Repository.RepositoryItemPictureEdit();
            this.label1 = new System.Windows.Forms.Label();
            ((System.ComponentModel.ISupportInitialize)(this.gridControl1)).BeginInit();
            ((System.ComponentModel.ISupportInitialize)(this.gridView1)).BeginInit();
            ((System.ComponentModel.ISupportInitialize)(this.repositoryItemComboBox1)).BeginInit();
            ((System.ComponentModel.ISupportInitialize)(this.repositoryItemPictureEdit1)).BeginInit();
            this.SuspendLayout();
            // 
            // gridControl1
            // 
            this.gridControl1.Dock = System.Windows.Forms.DockStyle.Fill;
            this.gridControl1.EmbeddedNavigator.Name = "";
            this.gridControl1.Location = new System.Drawing.Point(0, 23);
            this.gridControl1.LookAndFeel.SkinName = "The Asphalt World";
            this.gridControl1.LookAndFeel.UseDefaultLookAndFeel = false;
            this.gridControl1.MainView = this.gridView1;
            this.gridControl1.Name = "gridControl1";
            this.gridControl1.RepositoryItems.AddRange(new DevExpress.XtraEditors.Repository.RepositoryItem[] {
            this.repositoryItemPictureEdit1,
            this.repositoryItemComboBox1});
            this.gridControl1.Size = new System.Drawing.Size(527, 286);
            this.gridControl1.TabIndex = 0;
            this.gridControl1.ViewCollection.AddRange(new DevExpress.XtraGrid.Views.Base.BaseView[] {
            this.gridView1});
            // 
            // gridView1
            // 
            this.gridView1.Columns.AddRange(new DevExpress.XtraGrid.Columns.GridColumn[] {
            this.columnID,
            this.columnName,
            this.columnColor,
            this.columnImage});
            this.gridView1.GridControl = this.gridControl1;
            this.gridView1.Name = "gridView1";
            this.gridView1.OptionsView.ShowGroupPanel = false;
            this.gridView1.RowHeight = 33;
            this.gridView1.CustomUnboundColumnData += new DevExpress.XtraGrid.Views.Base.CustomColumnDataEventHandler(this.gridView1_CustomUnboundColumnData);
            // 
            // columnID
            // 
            this.columnID.Caption = "ID";
            this.columnID.FieldName = "ID";
            this.columnID.Name = "columnID";
            this.columnID.OptionsColumn.ReadOnly = true;
            this.columnID.Visible = true;
            this.columnID.VisibleIndex = 0;
            this.columnID.Width = 81;
            // 
            // columnName
            // 
            this.columnName.Caption = "Name";
            this.columnName.FieldName = "Name";
            this.columnName.Name = "columnName";
            this.columnName.Visible = true;
            this.columnName.VisibleIndex = 1;
            this.columnName.Width = 132;
            // 
            // columnColor
            // 
            this.columnColor.Caption = "Color";
            this.columnColor.ColumnEdit = this.repositoryItemComboBox1;
            this.columnColor.FieldName = "Color";
            this.columnColor.Name = "columnColor";
            this.columnColor.Visible = true;
            this.columnColor.VisibleIndex = 2;
            this.columnColor.Width = 152;
            // 
            // repositoryItemComboBox1
            // 
            this.repositoryItemComboBox1.AutoHeight = false;
            this.repositoryItemComboBox1.Buttons.AddRange(new DevExpress.XtraEditors.Controls.EditorButton[] {
            new DevExpress.XtraEditors.Controls.EditorButton(DevExpress.XtraEditors.Controls.ButtonPredefines.Combo)});
            this.repositoryItemComboBox1.Items.AddRange(new object[] {
            "Black",
            "Blue",
            "Green",
            "Magenta",
            "Orange",
            "Pink",
            "Red",
            "White",
            "Yellow"});
            this.repositoryItemComboBox1.Name = "repositoryItemComboBox1";
            // 
            // columnImage
            // 
            this.columnImage.Caption = "Image (unbound)";
            this.columnImage.ColumnEdit = this.repositoryItemPictureEdit1;
            this.columnImage.FieldName = "Image";
            this.columnImage.Name = "columnImage";
            this.columnImage.OptionsColumn.AllowEdit = false;
            this.columnImage.UnboundType = DevExpress.Data.UnboundColumnType.Object;
            this.columnImage.Visible = true;
            this.columnImage.VisibleIndex = 3;
            this.columnImage.Width = 118;
            // 
            // repositoryItemPictureEdit1
            // 
            this.repositoryItemPictureEdit1.Name = "repositoryItemPictureEdit1";
            // 
            // label1
            // 
            this.label1.Dock = System.Windows.Forms.DockStyle.Top;
            this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif", 9F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(204)));
            this.label1.Location = new System.Drawing.Point(0, 0);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(527, 23);
            this.label1.TabIndex = 1;
            this.label1.Text = "What\'s your favorite color?";
            // 
            // Form1
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(527, 309);
            this.Controls.Add(this.gridControl1);
            this.Controls.Add(this.label1);
            this.Name = "Form1";
            this.Text = "Form1";
            ((System.ComponentModel.ISupportInitialize)(this.gridControl1)).EndInit();
            ((System.ComponentModel.ISupportInitialize)(this.gridView1)).EndInit();
            ((System.ComponentModel.ISupportInitialize)(this.repositoryItemComboBox1)).EndInit();
            ((System.ComponentModel.ISupportInitialize)(this.repositoryItemPictureEdit1)).EndInit();
            this.ResumeLayout(false);

        }
        #endregion

        /// 

        /// The main entry point for the application.
        /// 
        [STAThread]
        static void Main() 
        {
            Application.Run(new Form1());
        }

        private void InitData() {
            string DBFileName = DevExpress.Utils.FilesHelper.FindingFileName(Application.StartupPath, "db.mdb");
            if(DBFileName != "") {
                DataSet ds = new DataSet();
                string con = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + DBFileName;
                System.Data.OleDb.OleDbDataAdapter oleDbDataAdapter = new System.Data.OleDb.OleDbDataAdapter("SELECT * FROM PeopleColors", con);
                oleDbDataAdapter.Fill(ds, "PeopleColors");
                gridControl1.DataSource = ds.Tables["PeopleColors"];
            }
        }

        string ImageDir = @"Images\";
        Hashtable Images = new Hashtable();

        //获取文件路径
        string GetFileName(string color) {         
            if(color == null || color == string.Empty)
                return string.Empty;                
            return color + ".jpg";            
        }

        private void gridView1_CustomUnboundColumnData(object sender, DevExpress.XtraGrid.Views.Base.CustomColumnDataEventArgs e) {
            if(e.Column.FieldName == "Image" && e.IsGetData) {
                GridView view = sender as GridView;

                string colorName = (string)((DataRowView)e.Row)["Color"];
                string fileName = GetFileName(colorName).ToLower();
                if(!Images.ContainsKey(fileName)) {
                    Image img = null;
                    try {
                        string filePath = DevExpress.Utils.FilesHelper.FindingFileName(Application.StartupPath, ImageDir + fileName, false);
                        img = Image.FromFile(filePath);
                    }
                    catch {
                    }
                    Images.Add(fileName, img);
                }
                e.Value = Images[fileName];
            }
        }
    }
}