Merge pull request #3 from SyncfusionExamples/Rabina4363sf-patch-1

KB-8530_Update README.md

Author: vijayarasan

README.md

@@ -1,5 +1,100 @@
-# How to show the total hours and minutes of DateTime column in summary row using custom aggregate?
+# How to show the total summary value in DateTime format using custom aggregate in WinForms DataGrid (SfDataGrid)
 
-## About the example
+## Show the total summary value in DateTime format
+You can implement your own summary aggregate functions using the [GridSummaryColumn.CustomAggregate](https://help.syncfusion.com/cr/windowsforms/Syncfusion.WinForms.DataGrid.GridSummaryColumn.html#Syncfusion_WinForms_DataGrid_GridSummaryColumn_CustomAggregate) property when built-in aggregate functions do not meet your requirement. The summary value can be calculated based on any custom logic.
 
-This example illustrates how to calculate the total time from a column and display the result in HH:MM format on the table summary row by creating custom summary aggregate. 
+In the following example, the Time column of [WinForms DataGrid](https://www.syncfusion.com/winforms-ui-controls/datagrid) (SfDataGrid) displays time in minutes. The custom summary aggregate for the summary column is created to display the total time in HH:MM format.
+
+### C#  
+
+```C#  
+
+public Form2()
+{
+    InitializeComponent();
+    this.sfDataGrid.DataSource = this.CreateTable();
+    this.sfDataGrid.TableSummaryRows.Add(new GridTableSummaryRow()
+    {
+        Name = "tableSumamryTrue",
+        ShowSummaryInRow = false,
+        Title = "Total :  {TotalTime}",
+        SummaryColumns = new System.Collections.ObjectModel.ObservableCollection<Syncfusion.Data.ISummaryColumn>()
+        {
+            new GridSummaryColumn()
+            {
+                Name = "TotalTime",
+                CustomAggregate=new CustomSummary(),
+                SummaryType=SummaryType.Custom,
+                Format="Total time : {TotalHours}",
+                MappingName="Time in minutes"
+            },
+        }
+    });
+}
+ 
+public class CustomSummary : ISummaryAggregate
+{
+    public CustomSummary()
+    { }
+    private string totalHours;
+    public string TotalHours { get { return totalHours; } set { totalHours = value; } }
+    public Action<IEnumerable, string, PropertyDescriptor> CalculateAggregateFunc()
+    {
+        return (items, property, pd) =>
+        {
+            var enumerableItems = items as IEnumerable<SalesByYear>;
+ 
+            //To check the summary format of the summary row.
+            if (pd.Name == "TotalHours")
+            {
+                int total = 0;
+                foreach (var item in items)
+                {
+                    DataRowView dr = item as DataRowView;
+                    total += int.Parse(dr["Time in minutes"].ToString());
+                }
+ 
+                this.totalHours = total / 60 + " Hours : " + total % 60 + " minutes";
+            }
+        };
+    }
+}
+```
+### VB
+
+```VB
+
+Public Sub New()
+ InitializeComponent()
+ Me.sfDataGrid.DataSource = Me.CreateTable()
+ Me.sfDataGrid.TableSummaryRows.Add(New GridTableSummaryRow() With {.Name = "tableSumamryTrue", .ShowSummaryInRow = False, .Title = "Total :  {TotalTime}", .SummaryColumns =      New System.Collections.ObjectModel.ObservableCollection(Of Syncfusion.Data.ISummaryColumn) (New Syncfusion.Data.ISummaryColumn() {New GridSummaryColumn() With {.Name = "TotalTime",     .CustomAggregate = New CustomSummary(), .SummaryType=SummaryType.Custom, .Format="Total time : {TotalHours}", .MappingName="Time in minutes"}})})
+End Sub
+ 
+Public Class CustomSummary
+ Implements ISummaryAggregate
+ Public Sub New()
+ End Sub
+    Private _totalHours As String
+    Public Property TotalHours() As String
+        Get
+            Return _totalHours
+        End Get
+        Set(ByVal value As String)
+            _totalHours = value
+        End Set
+    End Property
+    Public Function CalculateAggregateFunc() As Action(Of IEnumerable, String, PropertyDescriptor) Implements ISummaryAggregate.CalculateAggregateFunc
+        Return Sub(items, [property], pd)
+                   If pd.Name = "TotalHours" Then
+                       Dim total As Integer = 0
+                       For Each item In items
+                           Dim dr As DataRowView = TryCast(item, DataRowView)
+                           total += Integer.Parse(dr("Time in minutes").ToString())
+                       Next item
+                       Me._totalHours = total \ 60 & " Hours : " & total Mod 60 & " minutes"
+                   End If
+               End Sub
+    End Function
+End Class
+```
+