![sl xamGrid Custom Groupby 01.png](images/sl_xamGrid_Custom_Groupby_01.png)
Please note that this control has been retired and is now obsolete to the XamDataGrid control, and as such, we recommend migrating to that control. It will not be receiving any new features, bug fixes, or support going forward. For help or questions on migrating your codebase to the XamDataGrid, please contact support.
The xamGrid™ control’s GroupBy feature, by default, places data of the same values into groups. You can customize the condition to group items by implementing the generic IEqualityComparer interface and provide the type that matches the column’s underlying data type. A column in xamGrid exposes the GroupByComparer property that you can set to your custom comparer.
The following code shows you how to set a column to group values by ranges of 0-25, 25-50, 50-75, and 75 or more. The example uses a custom comparer that implements the IEqualityComparer interface for integers. It also uses the GroupedValuesConverter class which implements the IValueConverter interface to display a custom value for each GroupBy row; in this example, each GroupBy row should label the range of values for the items grouped within. The GroupedValuesConverter class evaluates the original GroupBy row value and returns a string labeling the range that the value belongs to. The DataUtil class is provided for you.
In XAML:
<UserControl.Resources> <local:DataUtil x:Key="DataUtil" /> <helper:GroupByCustomComparer x:Key="GroupByCustomComparer" /> <helper:GroupedValuesConverter x:Key="GroupedValuesConverter" /> </UserControl.Resources> <Grid x:Name="LayoutRoot" Background="White"> <ig:XamGrid x:Name="xamGrid1" ItemsSource="{Binding Source={StaticResource DataUtil}, Path=Products}"> <ig:XamGrid.GroupBySettings> <ig:GroupBySettings AllowGroupByArea="Top" /> </ig:XamGrid.GroupBySettings> <ig:XamGrid.Columns> <!-- Set up custom comparer --> <ig:TextColumn Key="UnitsInStock" GroupByComparer="{StaticResource GroupByCustomComparer}"> <!-- Use data template to set custom caption for each Groupby row with value converter --> <ig:TextColumn.GroupByItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <TextBlock Text="{Binding Value, Converter={StaticResource GroupedValuesConverter}}" /> </StackPanel> </DataTemplate> </ig:TextColumn.GroupByItemTemplate> </ig:TextColumn> </ig:XamGrid.Columns> </ig:XamGrid> </Grid>
In Visual Basic:
Public Class GroupByCustomComparer Implements IEqualityComparer(Of Integer) Public Function Equals1(ByVal x As Integer, ByVal y As Integer) As Boolean Implements System.Collections.Generic.IEqualityComparer(Of Integer).Equals ' Compares values for each group created by GetHashCode ' Since no additional conditions is required, just return true Return True End Function Public Function GetHashCode1(ByVal obj As Integer) As Integer Implements System.Collections.Generic.IEqualityComparer(Of Integer).GetHashCode ' Compare value and return the same hashcode for each group If obj >= 0 AndAlso obj < 25 Then Return "0".GetHashCode() End If If obj >= 25 AndAlso obj < 50 Then Return "25".GetHashCode() End If If obj >= 50 AndAlso obj < 75 Then Return "50".GetHashCode() End If If obj >= 75 Then Return "75".GetHashCode() Else Return obj.GetHashCode() End If End Function End Class
In Visual Basic:
Public Class GroupedValuesConverter Implements IValueConverter Public Function Convert(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.Convert ' Get value to convert Dim val As Integer = CInt(value) ' Compare value and returns a description of the value's range, displayed in each Groupby row If val >= 0 AndAlso val < 25 Then Return "Under 25 Units in Stock" ElseIf val >= 25 AndAlso val < 50 Then Return "Between 25 and 50 Units in Stock" ElseIf val >= 50 AndAlso val < 75 Then Return "Between 50 and 75 Units in Stock" ElseIf val >= 75 Then Return "75 or Greater Units in Stock" Else Return val.ToString() End If End Function Public Function ConvertBack(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.ConvertBack Throw New NotImplementedException() End Function End Class
In C#:
public class GroupByCustomComparer : IEqualityComparer<int> { #region IEqualityComparer<int> Members public bool Equals(int x, int y) { // Compares values for each group created by GetHashCode // Since no additional conditions is required, just return true return true; } public int GetHashCode(int obj) { // Compare value and return the same hashcode for each group if (obj >= 0 && obj < 25) return "0".GetHashCode(); if (obj >= 25 && obj < 50) return "25".GetHashCode(); if (obj >= 50 && obj < 75) return "50".GetHashCode(); if (obj >= 75) return "75".GetHashCode(); else return obj.GetHashCode(); } #endregion }
In C#:
public class GroupedValuesConverter : IValueConverter { #region IValueConverter Members public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { // Get value to convert int val = (int)value; // Compare value and returns a description of the value's range, displayed in each Groupby row if (val >= 0 && val < 25) return "Under 25 Units in Stock"; else if (val >= 25 && val < 50) return "Between 25 and 50 Units in Stock"; else if (val >= 50 && val < 75) return "Between 50 and 75 Units in Stock"; else if (val >= 75) return "75 or Greater Units in Stock"; else return val.ToString(); } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) { throw new NotImplementedException(); } #endregion }