GridView.GetGroupRowValue(Int32) Method

Gets the value of the specified grouping column by which data is grouped.

Namespace: DevExpress.XtraGrid.Views.Grid

Assembly: DevExpress.XtraGrid.v23.2.dll

NuGet Packages: DevExpress.Win.Grid, DevExpress.Win.Navigation

Declaration

C#

public virtual object GetGroupRowValue(
    int rowHandle
)

VB.NET

Public Overridable Function GetGroupRowValue(
    rowHandle As Integer
) As Object

Parameters

Name	Type	Description
rowHandle	Int32	An integer value representing the handle of the required group row.

Returns

Type	Description
Object	The value of the grouping column by which data is grouped.

Remarks

Each group row contains one or more underlying data rows. The GetGroupRowValue method returns the value of the grouping column in the first data row within the specified group. Usually this value is common to all the data rows within the group. However, if the rows are grouped using a custom grouping algorithm (via the GridView.CustomColumnGroup event) the rows with different values in the grouping column can be combined into the same group.

For instance, the value returned by the GetGroupRowValue method can be used when customizing the group rows’ display text via the GridView.CustomDrawGroupRow event.

Note

Detail pattern Views do not contain data and they are never displayed within XtraGrid. So, the GetGroupRowValue member must not be invoked for these Views. The GetGroupRowValue member can only be used with Views that display real data within the Grid Control. Use the following methods to access these Views with which an end user interacts at runtime.

• GridControl.MainView - returns the top most View in a grid;
• GridControl.FocusedView - returns the focused View;
• GridControl.DefaultView - returns the currently maximized View;
• the sender parameter of View specific events;
• GridView.GetDetailView - returns a detail clone View for a specific master row.

Example

Assume that a Grid View’s “Order Sum” column contains numbers. When grouping is applied to this column, the rows which have values between 0 and 99 in this column should be combined into a single group, the rows whose values fall between 100 and 199 should be combined into another group, etc. To provide custom grouping logic the column’s GridColumn.SortMode property should be set to ColumnSortMode.Custom and the GridView.CustomColumnGroup event should be handled to implement the algorithm. In the following example the event’s Result parameter is set to 0 if the two rows being compared should be placed within the same group.

The ColumnView.CustomColumnDisplayText event is handled to replace the default text displayed within group rows.

The result of data being custom grouped is shown below:

C#

using DevExpress.XtraGrid;
using DevExpress.XtraGrid.Views.Base;
using DevExpress.XtraGrid.Views.Grid;
using DevExpress.XtraGrid.Views.Grid.ViewInfo;

// ...
gridView1.Columns["Order Sum"].SortMode = ColumnSortMode.Custom;

private void gridView1_CustomColumnGroup(object sender, CustomColumnSortEventArgs e) {
   if(e.Column.FieldName == "Order Sum") {
      double x = Math.Floor(Convert.ToDouble(e.Value1) / 100);
      double y = Math.Floor(Convert.ToDouble(e.Value2) / 100);
      int res = Comparer.Default.Compare(x, y);
      if(x > 14 && y > 14) res = 0;
      e.Result = res;
      e.Handled = true;
   }
}

private void gridView_CustomColumnDisplayText(object sender, DevExpress.XtraGrid.Views.Base.CustomColumnDisplayTextEventArgs e) {
    GridView view = sender as GridView;
    if(view == null) return;
    if (e.Column.FieldName == "Order Sum" && e.IsForGroupRow) {
        double rowValue = Convert.ToDouble(view.GetGroupRowValue(e.GroupRowHandle, e.Column));
        double val = Math.Floor(rowValue / 100);
        string groupRowInterval = string.Format("{0:c} - {1:c} ", val * 100, (val + 1) * 100);
        if (val > 14)
            groupRowInterval = string.Format(">= {0:c} ", val * 100);
        e.DisplayText = "Order Sum: " + groupRowInterval;
    }
}

VB.NET

Imports DevExpress.XtraGrid
Imports DevExpress.XtraGrid.Views.Base
Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.XtraGrid.Views.Grid.ViewInfo

   ' ...
   GridView1.Columns("Order Sum").SortMode = ColumnSortMode.Custom

Private Sub GridView1_CustomColumnGroup(ByVal sender As Object, _
ByVal e As CustomColumnSortEventArgs) Handles GridView1.CustomColumnGroup
   If e.Column.FieldName = "Order Sum" Then
      Dim x As Double = Math.Floor(Convert.ToDouble(e.Value1) / 100)
      Dim y As Double = Math.Floor(Convert.ToDouble(e.Value2) / 100)
      Dim res As Integer = Comparer.Default.Compare(x, y)
      If x > 14 And y > 14 Then res = 0
      e.Result = res
      e.Handled = True
   End If
End Sub

Private Sub GridView1_CustomColumnDisplayText(ByVal sender As Object, _
ByVal e As DevExpress.XtraGrid.Views.Base.CustomColumnDisplayTextEventArgs) Handles GridView1.CustomColumnDisplayText
    Dim view As GridView = sender
    If view Is Nothing Then
        Return
    End If
    If e.Column.FieldName = "Order Sum" AndAlso e.IsForGroupRow Then
        Dim rowValue As Double = Convert.ToDouble(view.GetGroupRowValue(e.GroupRowHandle, e.Column))
        Dim val As Double = Math.Floor(rowValue / 100)
        Dim groupRowInterval As String = String.Format("{0:c} - {1:c} ", val * 100, (val + 1) * 100)
        If val > 14 Then
            groupRowInterval = String.Format(">= {0:c} ", val * 100)
        End If
        e.DisplayText = Convert.ToString("Order Sum: ") & groupRowInterval
    End If
End Sub