DataGridView控件添加鼠标选定ToolTip显示合计

/// <summary>        /// DataGridView多行选择求和        /// </summary>        /// <param name="myDataGridView">要求合计提示的DataGridView控件</param>        /// <param name="TooLar">传入的ToolTip控件.</param>        /// <returns></returns>        public bool DataGridViewSum(DataGridView myDataGridView, ToolTip TooLar)        {            if (myDataGridView.SelectedCells.Count < 2)            {                TooLar.RemoveAll();                return false;            }            //如果选择的单元格是全部，且大于：１００００，则认为是不是求合计的操作            if (myDataGridView.SelectedCells.Count > 10000 && myDataGridView.SelectedCells.Count == myDataGridView.GetCellCount(DataGridViewElementStates.None))            {                TooLar.RemoveAll();                return false;            }             DataSet DS = new DataSet();            DataTable DtGroup = new DataTable("DtGroup");//保存列名            System.Collections.ArrayList NameMaxLength = new System.Collections.ArrayList();//保存DT中列名的长度            System.Collections.ArrayList ValueMaxLength = new System.Collections.ArrayList();//保存DT中列名的长度            DataTable DT = new DataTable("DT");//保存列名及数据            DtGroup.Columns.Add("ColumnName", System.Type.GetType("System.String"));//字段名             DT.Columns.Add("ColumnName", System.Type.GetType("System.String"));//字段名            DT.Columns.Add("ColumnValue", System.Type.GetType("System.Decimal"));//字段值             foreach (DataGridViewCell DC in myDataGridView.SelectedCells)            {                if (DC.ValueType.Name.ToLower() == "decimal" || DC.ValueType.Name.ToLower() == "int32")                {                    DataRow DR;                    DR = DT.NewRow();                    DR["ColumnName"] = myDataGridView.Columns[DC.ColumnIndex].Name;                    if (DC.Value == null)                    {                        DR["ColumnValue"] = 0;                    }                    else                    {                        DR["ColumnValue"] = DC.Value;                        ValueMaxLength.Add(DC.Value.ToString().Length);                    }                    DT.Rows.Add(DR);                    //在现有DtColName中查找是否包含了这个列名                    if (DtGroup.Select("ColumnName='" + myDataGridView.Columns[DC.ColumnIndex].Name + "'").Length == 0)                    {                        DataRow DR1;                        DR1 = DtGroup.NewRow();                        DR1["ColumnName"] = myDataGridView.Columns[DC.ColumnIndex].Name;                        DtGroup.Rows.Add(DR1);                        NameMaxLength.Add(myDataGridView.Columns[DC.ColumnIndex].Name.Length);                    }                }            }            DS.Tables.Add(DT);            DS.Tables.Add(DtGroup);             DataRelation dRelation = new DataRelation("dRelation", DS.Tables["DtGroup"].Columns["ColumnName"], DS.Tables["DT"].Columns["ColumnName"]);            DS.Relations.Add(dRelation);            DtGroup.Columns.Add("ColumnSum").Expression = "sum(child(dRelation).ColumnValue)";            string decSum = DT.Compute("sum(ColumnValue)", "").ToString();             NameMaxLength.Add("总合计：".Length);            ValueMaxLength.Add(decSum.Length);            DtGroup.AcceptChanges();            string Tall = "";            NameMaxLength.Sort();            ValueMaxLength.Sort();            int NameMaxLen = 0;            NameMaxLen = int.Parse(NameMaxLength[NameMaxLength.Count - 1].ToString());            int ValueMaxLen = 0;            ValueMaxLen = int.Parse(ValueMaxLength[ValueMaxLength.Count - 1].ToString());            for (int i = 0; i < DtGroup.Rows.Count; i++)            {                string strOneLine = "";                strOneLine = (DtGroup.Rows[i]["ColumnName"].ToString() + "：").PadRight(NameMaxLen + 1, '　');                strOneLine = strOneLine + DtGroup.Rows[i]["ColumnSum"].ToString().PadLeft(ValueMaxLen, ' ');                Tall = Tall + strOneLine + System.Environment.NewLine;            }            Tall = Tall + "总合计：".PadRight(NameMaxLen + 1, '　') + decSum.PadLeft(ValueMaxLen, ' ');             myDataGridView.ShowCellToolTips = false;            TooLar.ToolTipIcon = ToolTipIcon.Info;            TooLar.IsBalloon = true;//汽球形状            TooLar.ToolTipTitle = "鼠标选定合计信息：";            TooLar.UseAnimation = true;//使用动画效果            TooLar.UseFading = true;//淡入淡出效果            TooLar.BackColor = Color.Wheat;//工具提示的背景色            TooLar.AutoPopDelay = 10000;//显示时间            TooLar.RemoveAll();            TooLar.SetToolTip(myDataGridView, Tall);            DT.Dispose();            DtGroup.Dispose();            DS.Dispose();            GC.Collect();            return true;        }