gridcontrol 图片列异步加载

在gridview中指定一列，将ColumnEdit设置成pictureEdit

在使用showDialog这里窗体后，需要frm.Dispose()将资源释放

1.将该列的UnboundType属性设置为bound(默认值)以外的数据类型

2.为该列设置一个窗体内全局唯一的FieldName，这个FieldName不能是窗体中绑定数据源的的列，否则不会触发绑定事件

3.处理CustomUnboundColumnData事件

            gridView1.CustomUnboundColumnData += (s, e) => {
                if (e.Column.Name == colImg1.Name)
                {
                    //Console.WriteLine(colImg1.Name + ":" +DateTime.Now);
                    var it = e.Row as Q_SymptomRepositoryItem;
                    if (ImgDic.ContainsKey(it.Img1))
                    {
                        e.Value = ImgDic[it.Img1];
                    }
                    else
                    {
                        e.Value = XFormExtension.LoadingImgLazy.Value;
                    }
                }
            };

4.加载数据时启动图片异步下载，完成后使用SyncContext.Post刷新gridview

        private void LoadImageSync(List<Q_SymptomRepositoryItem> list)
        {
            var imgList = list;
            ThreadPool.QueueUserWorkItem((o) =>
            {
                using (WebClient wc = new WebClient())
                {
                    for (int i = 0; i < imgList.Count; i++)
                    {
                        var item = imgList[i];
                        try
                        {

                            if (string.IsNullOrWhiteSpace(item.Img1)) continue;
                            var bytes = wc.DownloadData(@"http://192.168.9.5:7111/getFile.ashx?rtype=repository&id=" + item.RecId);

                            using (var ms = new MemoryStream(bytes))
                            {
                                ImgDic[item.Img1] = XFormExtension.EnsureImage(Image.FromStream(ms));

                                if (!IsRunning) return;


                                SyncContext.Post((ox) =>
                                {
                                    gridView1.RefreshData();

                                }, null);
                            }
                        }
                        catch (Exception ex)
                        {
                            Console.WriteLine("下载图片->" + ex.Message, "错误");
                        }


                    }
                }

            });
        }

5.完整代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Linq;
using System.Windows.Forms;
using DevExpress.XtraEditors;
using DevExpress.XtraGrid;

namespace WinDetectionClockAdmin
{
    using DetectionClock.EFModel;
    using System.Collections.Concurrent;
    using System.Threading;
    using System.Net;
    using System.IO;
    using DevExpress.XtraGrid.Views.Grid.ViewInfo;
    using WinDetectionClock;

    public partial class frmSymptomRepositoryItem : DevExpress.XtraEditors.XtraForm
    {
        public GridControl MainGrid { get; set; }
        private SynchronizationContext SyncContext { get; set; }
        public Q_SymptomRepository SymptomRepository { get; set; }
        public bool IsRunning = false;

        private ConcurrentDictionary<string, Image> ImgDic = new ConcurrentDictionary<string, Image>();

        public frmSymptomRepositoryItem(Q_SymptomRepository repository):this()
        {
            SymptomRepository = repository;
            //加载数据
            LoadData();
        }
        public frmSymptomRepositoryItem()
        {
            InitializeComponent();
            MainGrid = gridControl1;
            SyncContext = SynchronizationContext.Current;
            this.StartPosition = FormStartPosition.CenterParent;

            #region 配置 gridControl 

            this.ConfigGrid(gridControl1, true);
            gridView1.CustomUnboundColumnData += (s, e) => {
                if (e.Column.Name == colImg1.Name)
                {
                    //Console.WriteLine(colImg1.Name + ":" +DateTime.Now);
                    var it = e.Row as Q_SymptomRepositoryItem;
                    if (ImgDic.ContainsKey(it.Img1))
                    {
                        e.Value = ImgDic[it.Img1];
                    }
                    else
                    {
                        e.Value = XFormExtension.LoadingImgLazy.Value;
                    }
                }
            };
       
            gridControl1.MouseDoubleClick += (s, e) =>
            {
                if (e.Button == System.Windows.Forms.MouseButtons.Left)
                {
                    GridHitInfo hInfo = gridView1.CalcHitInfo(new Point(e.X, e.Y));
                    if (!hInfo.InRow) return; //确保点的是数据行而不是标头
                   
                    var ent = qSymptomRepositoryItemBindingSource.Current as Q_SymptomRepositoryItem;
                    if (ent == null) return;

                    //hInfo.Column==null 标示点了行头
                    if (hInfo.Column!=null && hInfo.Column.Caption == "图片")
                    {
                        
                            ////var img = gridView1.GetFocusedValue() as Image;
                            ////new frmPhotoDetail(img).ShowDialog();
                            ////return;
                        
                    }
                   
                    //双击其他标示修改
                    btnModify.PerformClick();
                    
                }
            };
            gridControl1.MouseUp += (s, e) =>
            {
                if (e.Button == System.Windows.Forms.MouseButtons.Right)
                {
                    GridHitInfo hInfo = gridView1.CalcHitInfo(new Point(e.X, e.Y));
                    if (hInfo.InRow)
                    {
                        var ent = qSymptomRepositoryItemBindingSource.Current as Q_SymptomRepositoryItem;
                        if (ent != null)
                        {
                            if (hInfo.Column != null && hInfo.Column.Caption == "图片")
                            {
                                popupMenu1.ShowPopup(Control.MousePosition);
                            }
                        }
                    }
                }
            };
            #endregion

            IsRunning = true;
           
        }
        #region 窗体关闭处理
        protected override void OnClosing(CancelEventArgs e)
        {
            IsRunning = false;
            base.OnClosing(e);
        }
        protected override void OnClosed(EventArgs e)
        {
            base.OnClosed(e);
            ImgDic.ToList().ForEach(ent =>
            {
                ent.Value.Dispose();
            });
        }
        #endregion
        #region ToolBar Action

        private void LoadData()
        {
            using (var ctx = DBCtx.GetCtx())
            {
                var list= ctx.Q_SymptomRepositoryItem.Where(ent => ent.MainId == SymptomRepository.RecId).ToList();
                qSymptomRepositoryItemBindingSource.DataSource = list;

              
                #region 加载图片信息
                LoadImageSync(list);
                #endregion
                
            }
        }

        private void LoadImageSync(List<Q_SymptomRepositoryItem> list)
        {
            var imgList = list;
            ThreadPool.QueueUserWorkItem((o) =>
            {
                using (WebClient wc = new WebClient())
                {
                    for (int i = 0; i < imgList.Count; i++)
                    {
                        var item = imgList[i];
                        try
                        {

                            if (string.IsNullOrWhiteSpace(item.Img1)) continue;
                            var bytes = wc.DownloadData(@"http://192.168.9.5:7111/getFile.ashx?rtype=repository&id=" + item.RecId);

                            using (var ms = new MemoryStream(bytes))
                            {
                                ImgDic[item.Img1] = XFormExtension.EnsureImage(Image.FromStream(ms));

                                if (!IsRunning) return;


                                SyncContext.Post((ox) =>
                                {
                                    gridView1.RefreshData();

                                }, null);
                            }
                        }
                        catch (Exception ex)
                        {
                            Console.WriteLine("下载图片->" + ex.Message, "错误");
                        }


                    }
                }

            });
        }

        private void btnAdd_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            var frm = new frmSymptomRepositoryItemEdit();
            frm.Owner = this;
            if (frm.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                qSymptomRepositoryItemBindingSource.Add(frm.NewEnt);
                qSymptomRepositoryItemBindingSource.MoveLast();
                LoadImageSync(new List<Q_SymptomRepositoryItem>() { frm.NewEnt as Q_SymptomRepositoryItem });
            }
        }

        private void btnModify_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
           

            var ent = qSymptomRepositoryItemBindingSource.Current as Q_SymptomRepositoryItem;

            if (ent == null) return;

            var old = this.Snapshoot<Q_SymptomRepositoryItem>(ent);

            var frm = new frmSymptomRepositoryItemEdit(ent);
            frm.Owner = this;
            if (frm.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                qSymptomRepositoryItemBindingSource.ResetCurrentItem();

                LoadImageSync(new List<Q_SymptomRepositoryItem>() { ent });
            }
            else
            {
                this.Restore<Q_SymptomRepositoryItem>(old, ent);
            }

            //连续加载测试
            btnModify.PerformClick();
        }

        private void btnDel_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            try
            {
                var cur = qSymptomRepositoryItemBindingSource.Current as Q_SymptomRepositoryItem;
                if (cur == null) return;

                if (MessageBox.Show("您确定删除吗?", "警告", MessageBoxButtons.YesNo, MessageBoxIcon.Warning) == System.Windows.Forms.DialogResult.Yes)
                {
                    using (var ctx = DBCtx.GetCtx())
                    {
                        var it = ctx.Q_SymptomRepositoryItem.FirstOrDefault(ent => ent.RecId == cur.RecId);
                        if (it != null)
                        {
                            ctx.DeleteObject(it);

                            ctx.SaveChanges();
                            qSymptomRepositoryItemBindingSource.Remove(cur);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private void btnRefresh_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            LoadData();
        }

        private void btnFilter_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            this.ShowFilter();
        }
        #endregion

        private void btnViewImg_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            popupMenu1.HidePopup();
            var img = gridView1.GetFocusedValue() as Image;
            new frmPhotoDetail(img).ShowDialog();
            return;
        }

        private void frmSymptomRepositoryItem_Load(object sender, EventArgs e)
        {  
            
            var timer = new  System.Windows.Forms.Timer();
            timer.Interval = 100;
            timer.Tick += (s, ie) =>
            {
                timer.Enabled = false;
                this.Close();
            };
            timer.Start();
        }
    }
}