ListView 虛擬模式2

轉：http://www.cnblogs.com/hcfalan/articles/1238493.html
虛擬模式下導入幾百萬數據只要幾秒中，非虛擬模式導入會卡死，收藏下！
public class ListViewEx : ListView
    {
        #region 虛擬模式相關操作

        ///<summary>
        /// 前臺行集合
        ///</summary>
        public List<ListViewItem> CurrentCacheItemsSource;

        public ListViewEx()
        {
            this.CurrentCacheItemsSource = new List<ListViewItem>();
            this.VirtualMode = true;
            this.RetrieveVirtualItem += new RetrieveVirtualItemEventHandler(listView_RetrieveVirtualItem);
        }

        ///<summary>
        /// 重置listview集合
        ///</summary>
        ///<param name="l"></param>
        public void ReSet(IList<ListViewItem> l)
        {
            this.CurrentCacheItemsSource.Clear();
            this.CurrentCacheItemsSource = new List<ListViewItem>();
            foreach (var item in l)
            {
                this.CurrentCacheItemsSource.Add(item);
            }
            this.VirtualListSize = this.CurrentCacheItemsSource.Count;
        }

        ///<summary>
        /// 虛擬模式事件
        ///</summary>
        ///<param name="sender"></param>
        ///<param name="e"></param>
        private void listView_RetrieveVirtualItem(object sender, RetrieveVirtualItemEventArgs e)
        {
            if (this.CurrentCacheItemsSource == null || this.CurrentCacheItemsSource.Count == 0)
            {
                return;
            }

            ListViewItem lv = this.CurrentCacheItemsSource[e.ItemIndex];
            e.Item = lv;
        }

        ///<summary>
        /// 獲取選中的第一行的指定tag值
        ///</summary>
        ///<param name="key"></param>
        ///<returns></returns>
        public string FirstSelectItemValue(string key)
        {
            int i = GetColumnsIndex(key);

            return this.CurrentCacheItemsSource[this.SelectedIndices[0]].SubItems[i].Text;
        }

        ///<summary>
        /// 獲取列名的索引
        ///</summary>
        ///<param name="key"></param>
        ///<returns></returns>
        public int GetColumnsIndex(string key)
        {
            int i = 0;
            for (; i < this.Columns.Count; i++)
            {
                if (this.Columns[i].Name == key)
                {
                    break;
                }
            }

            return i;
        }

        ///<summary>
        /// 獲取選中項
        ///</summary>
        ///<returns></returns>
        public List<ListViewItem> GetSelectItem()
        {
            List<ListViewItem> l = new List<ListViewItem>();
            foreach (var item in this.SelectedIndices)
            {
                l.Add(this.CurrentCacheItemsSource[int.Parse(item.ToString())]);
            }
            return l;
        }

        ///<summary>
        /// 獲取選中行的某列集合
        ///</summary>
        ///<param name="key"></param>
        ///<returns></returns>
        public List<string> GetListViewField(string key)
        {
            List<string> ids = new List<string>();

            foreach (var item in this.SelectedIndices)
            {
                string id = this.CurrentCacheItemsSource[int.Parse(item.ToString())].SubItems[GetColumnsIndex(key)].Text;
                ids.Add(id);
            }
            return ids;
        }

        private ListViewItemComparer mySorter;
        ///<summary>
        /// 排序
        ///</summary>
        ///<param name="e"></param>
        protected override void OnColumnClick(ColumnClickEventArgs e)
        {
            base.OnColumnClick(e);

            string dbType = this.Columns[e.Column].Tag.ToString();

            if (this.mySorter == null)
            {
                this.mySorter = new ListViewItemComparer(e.Column, SortOrder.Ascending, dbType);
            }
            else
            {
                if (this.mySorter.SortColumn == e.Column)
                {
                    if (this.mySorter.Order == SortOrder.Ascending)
                    {
                        this.mySorter.Order = SortOrder.Descending;
                    }
                    else
                    {
                        this.mySorter.Order = SortOrder.Ascending;
                    }
                }
                else
                {
                    this.mySorter.SortColumn = e.Column;
                    this.mySorter.Order = SortOrder.Ascending;
                }

                this.mySorter.DbType = dbType;

                this.CurrentCacheItemsSource.Sort(this.mySorter);

                this.Invalidate();
            }
        }
        #endregion

        #region 普通模式下排序
        /*普通模式下排序
        public void ReLoadColumn()
        {
            this.ListViewItemSorter = new ListViewItemComparer(0, SortOrder.Ascending, this.Columns[0].Tag.ToString());
        }

        protected override void OnColumnClick(ColumnClickEventArgs e)
        {
            base.OnColumnClick(e);

            string dbType = this.Columns[e.Column].Tag.ToString();


            if (this.ListViewItemSorter == null)
            {
                this.ListViewItemSorter = new ListViewItemComparer(e.Column, SortOrder.Ascending, dbType);
            }
            else
            {
                ListViewItemComparer comparer = this.ListViewItemSorter as ListViewItemComparer;
                if (comparer.SortColumn == e.Column)
                {
                    if (comparer.Order == SortOrder.Ascending)
                    {
                        comparer.Order = SortOrder.Descending;
                    }
                    else
                    {
                        comparer.Order = SortOrder.Ascending;
                    }
                }
                else
                {
                    comparer.SortColumn = e.Column;
                    comparer.Order = SortOrder.Ascending;
                }

                //MessageBox.Show(dbType);

                comparer.DbType = dbType;

                //僅僅改變了ListViewItemSorter屬性值，這裏不會自動調用Sort()方法，需要顯式指定執行Sort()方法實現排序。
                this.Sort();
            }
        }
        */
        #endregion

        #region ListView排序邏輯
        ///<summary>
        /// ListView排序邏輯
        ///</summary>
        private class ListViewItemComparer : System.Collections.Generic.IComparer<ListViewItem>
        {
            public string DbType;
            public ListViewItemComparer()
            {
                this.SortColumn = 0;
                this.Order = SortOrder.None;
            }

            public ListViewItemComparer(int column)
                : this()
            {
                this.SortColumn = column;
            }

            ///<summary>
            /// 
            ///</summary>
            ///<param name="column">哪列</param>
            ///<param name="sortOrder">排序方式</param>
            ///<param name="dbType">類型</param>
            public ListViewItemComparer(int column, SortOrder sortOrder, string dbType)
                : this(column)
            {
                Order = sortOrder;
                DbType = dbType.ToLower();
            }

            #region IComparer 成員
            public int Compare(ListViewItem x, ListViewItem y)
            {
                int result = 0;
                string c1 = "";
                string c2 = "";

                try
                {
                    c1 = x.SubItems[this.SortColumn].Text;
                    c2 = y.SubItems[this.SortColumn].Text;
                }
                catch (Exception ex)
                {
                    //    MessageBox.Show(ex.Message);
                    return 0;
                }

                switch (DbType)
                {
                    case "int":
                        result = Fn.IsInt(c1, 0) - Fn.IsInt(c2, 0);
                        break;

                    case "datetime":
                        DateTime t1 = Fn.IsDate(c1, DateTime.MinValue);
                        DateTime t2 = Fn.IsDate(c2, DateTime.MinValue);

                        if (DateTime.TryParse(c1, out t1) && DateTime.TryParse(c2, out t2))
                        {
                            int cha1 = Fn.IsInt((t1 - t2).TotalSeconds.ToString(), 0);
                            result = Fn.IsInt((t1 - t2).TotalSeconds.ToString(), 0);

                            if (cha1 == 0)
                                result = 0;
                            else if (cha1 < 0)
                                result = -1;
                            else
                                result = 1;
                        }
                        else
                        {
                            result = string.Compare(c1, c2);
                        }

                        break;

                    case "double":
                        double d1 = Fn.IsDouble(c1, 0);
                        double d2 = Fn.IsDouble(c2, 0);

                        if (d1 == d2)
                            result = 0;
                        else if (d1 < d2)
                            result = -1;
                        else
                            result = 1;
                        break;

                    default:
                        result = string.Compare(c1, c2);
                        break;
                }

                if (this.Order == SortOrder.Ascending)
                {
                    return result;
                }
                else if (this.Order == SortOrder.Descending)
                {
                    return (-result);
                }
                else
                {
                    return 0;
                }
            }
            #endregion

            ///<summary>
            /// 當前排序列
            ///</summary>
            public int SortColumn
            {
                get;
                set;
            }

            ///<summary>
            /// 當前列排序方式
            ///</summary>
            public SortOrder Order
            {
                get;
                set;
            }
        }
        #endregion
    }

主要功能使用方法:

添加列

AddLVCol("first", "null", "", 0); AddLVCol("id", "int", "", 0); AddLVCol("index", "int", "序號", 40); AddLVCol("name", "text", "產品名稱", 200); ... protected void AddLVCol(string pName, string pTag, string pText, int pWidth) { ColumnHeader ch = new ColumnHeader(); ch.Name = pName; ch.Tag = pTag; ch.Text = pText; ch.Width = pWidth; this.listV.Columns.Add(ch); }
添加內容

List<ListViewItem> listItem = new List<ListViewItem>();
listItem.Add.....

this.listV.ReSet(listItem); 

刪除內容時選擇列id集合

List<string> idList = this.listV.GetListViewField("id");

修改內容時獲取id

int id = int.Parse(this.listV.FirstSelectItemValue("id"));

獲當前選中的集合

List<ListViewItem> listData=this.listV.CurrentCacheItemsSource;