油王的菜鳥筆記

   <telerik:RadGrid ID="RadGrid1" GridLines="None" runat="server" AutoGenerateColumns="false" RenderMode="Lightweight"
            OnNeedDataSource="RadGrid1_NeedDataSource" OnCustomAggregate="RadGrid1_CustomAggregate"
            ShowFooter="true">
            <MasterTableView DataKeyNames="someColumn, moreData" ShowGroupFooter="true">
                <GroupByExpressions>
                    <telerik:GridGroupByExpression>
                        <SelectFields>
                            <telerik:GridGroupByField FieldAlias="moreData" FieldName="moreData"
                                HeaderValueSeparator=" field with value: "></telerik:GridGroupByField>
                        </SelectFields>
                        <GroupByFields>
                            <telerik:GridGroupByField FieldName="moreData" SortOrder="None"></telerik:GridGroupByField>
                        </GroupByFields>
                    </telerik:GridGroupByExpression>
                </GroupByExpressions>
                <Columns>
                    <telerik:GridBoundColumn DataField="id" HeaderText="id" UniqueName="id" Aggregate="Sum">
                    </telerik:GridBoundColumn>
                    
                    <telerik:GridBoundColumn DataField="firstField" HeaderText="firstField"
                        UniqueName="firstField">
                    </telerik:GridBoundColumn>
                    
                    <telerik:GridBoundColumn DataField="moreData" HeaderText="moreData"
                        UniqueName="moreData"
                        Aggregate="Custom" FooterAggregateFormatString="my Decimal SUM Aggregate: {0}">
                    </telerik:GridBoundColumn>
                  
                    <telerik:GridBoundColumn DataField="someColumn" HeaderText="someColumn"
                        UniqueName="someColumn"
                        Aggregate="Custom" FooterAggregateFormatString="my TimeSpan SUM Aggregate: {0}">
                    </telerik:GridBoundColumn>
                </Columns>
            </MasterTableView>
        </telerik:RadGrid>


   protected void RadGrid1_CustomAggregate(object sender, Telerik.Web.UI.GridCustomAggregateEventArgs e)
            {
                //get the column name it will be used for determining what to aggregate and for fetching data
                string colName = e.Column.UniqueName;

                //the group footer calculation is to be performed, we need only the corresponding group items data
                if (e.Item is GridGroupFooterItem)
                {
                    string msg = "group footer aggregate: ";

                    //get the corresponding group header as it provides child items from which we can obtain data
                    GridGroupHeaderItem correspondingHeader = (e.Item as GridGroupFooterItem).GroupHeaderItem;

                    //check column name to determine aggregation logic
                    if (colName == "moreData")
                    {
                        decimal counter = 0;
                        //get corresponding group items to iterate through and aggregate
                        GridItem[] groupChildItems = correspondingHeader.GetChildItems();
                        for (int i = 0; i < groupChildItems.Length; i++)
                        {
                            decimal currValue = (decimal)DataBinder.Eval((groupChildItems[i] as GridDataItem).DataItem, colName);
                            counter += currValue; //custom sum aggregate, implement aggregation here
                        }
                        e.Result = msg + counter;
                    }

                    if (colName == "someColumn")
                    {
                        TimeSpan totalTime = new TimeSpan(0);
                        GridItem[] groupChildItems = correspondingHeader.GetChildItems();
                        for (int i = 0; i < groupChildItems.Length; i++)
                        {
                            TimeSpan currValue = (TimeSpan)DataBinder.Eval((groupChildItems[i] as GridDataItem).DataItem, colName);
                            totalTime = totalTime.Add(currValue);
                        }
                        e.Result = msg + totalTime;
                    }
                }

                //the total grid footer that is not specific to a group, we need to aggregate all data
                if (e.Item is GridFooterItem)
                {
                    string msg = "Grid total footer aggregate: ";
                    if (colName == "moreData")
                    {
                        decimal counter = 0;
                        //Loop all items in the current grid to aggregate
                        foreach (GridDataItem item in RadGrid1.MasterTableView.Items)
                        {
                            decimal currValue = (decimal)item.GetDataKeyValue(colName);
                            counter += currValue;
                        }
                        e.Result = msg + counter;
                    }

                    if (colName == "someColumn")
                    {
                        TimeSpan totalTime = new TimeSpan(0);
                        foreach (GridDataItem item in RadGrid1.MasterTableView.Items)
                        {
                            TimeSpan currValue = (TimeSpan)item.GetDataKeyValue(colName);
                            totalTime = totalTime.Add(currValue);
                        }
                        e.Result = msg + totalTime;
                    }
                }
            }