GridControl.IsGroupRowHandle(Int32) Method

<Window x:Class="DXGrid_RowDoubleClick.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525" xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
        xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors">

    <Grid>
        <dxg:GridControl Name="grid" Control.MouseDoubleClick="grid_MouseDoubleClick">
            <dxg:GridControl.Columns>
                <dxg:GridColumn FieldName="ProductName">
                    <dxg:GridColumn.EditSettings>
                        <dxe:TextEditSettings HorizontalContentAlignment="Center" />
                    </dxg:GridColumn.EditSettings>
                </dxg:GridColumn>
                <dxg:GridColumn FieldName="UnitPrice">
                    <dxg:GridColumn.EditSettings>
                        <dxe:SpinEditSettings HorizontalContentAlignment="Left" />
                    </dxg:GridColumn.EditSettings>
                </dxg:GridColumn>
            </dxg:GridControl.Columns>
            <dxg:GridControl.View>
                <dxg:TableView Name="tView" />
            </dxg:GridControl.View>
        </dxg:GridControl>
    </Grid>
</Window>

Imports Microsoft.VisualBasic
Imports System.Windows
Imports System.Windows.Input
Imports DevExpress.Xpf.Grid

Namespace DXGrid_RowDoubleClick
    ''' <summary>
    ''' Interaction logic for MainWindow.xaml
    ''' </summary>
    Partial Public Class MainWindow
        Inherits Window
        Public Sub New()
            InitializeComponent()
            grid.ItemsSource = New ProductList()
        End Sub

        Private Sub grid_MouseDoubleClick(ByVal sender As Object, ByVal e As MouseButtonEventArgs)
            Dim rowHandle As Integer = tView.GetRowHandleByMouseEventArgs(e)
            If rowHandle = GridControl.InvalidRowHandle Then
                Return
            End If
            If grid.IsGroupRowHandle(rowHandle) Then
                MessageBox.Show("A group row has been double clicked.", "Info")
            Else
                MessageBox.Show("A data row has been double clicked.", "Info")
            End If
        End Sub
    End Class
End Namespace

Imports Microsoft.VisualBasic
Imports System.Collections.Generic
Imports System.Collections.ObjectModel

Public Class Product
    Private privateProductName As String
    Public Property ProductName() As String
        Get
            Return privateProductName
        End Get
        Set(ByVal value As String)
            privateProductName = value
        End Set
    End Property
    Private privateCountry As String
    Public Property Country() As String
        Get
            Return privateCountry
        End Get
        Set(ByVal value As String)
            privateCountry = value
        End Set
    End Property
    Private privateCity As String
    Public Property City() As String
        Get
            Return privateCity
        End Get
        Set(ByVal value As String)
            privateCity = value
        End Set
    End Property
    Private privateUnitPrice As Double
    Public Property UnitPrice() As Double
        Get
            Return privateUnitPrice
        End Get
        Set(ByVal value As Double)
            privateUnitPrice = value
        End Set
    End Property
    Private privateQuantity As Integer
    Public Property Quantity() As Integer
        Get
            Return privateQuantity
        End Get
        Set(ByVal value As Integer)
            privateQuantity = value
        End Set
    End Property
End Class

Public Class ProductList
    Inherits ObservableCollection(Of Product)
    Public Sub New()
        MyBase.New()
        Add(New Product() With {.ProductName = "Chang", .Country = "UK", .City = "Cowes", .UnitPrice = 19, .Quantity = 10})
        Add(New Product() With {.ProductName = "Gravad lax", .Country = "Italy", .City = "Reggio Emilia", .UnitPrice = 12.5, .Quantity = 16})
        Add(New Product() With {.ProductName = "Ravioli Angelo", .Country = "Brazil", .City = "Rio de Janeiro", .UnitPrice = 19, .Quantity = 12})
        Add(New Product() With {.ProductName = "Tarte au sucre", .Country = "Germany", .City = "QUICK-Stop", .UnitPrice = 22, .Quantity = 50})
        Add(New Product() With {.ProductName = "Steeleye Stout", .Country = "USA", .City = "Reggio Emilia", .UnitPrice = 18, .Quantity = 20})
        Add(New Product() With {.ProductName = "Pavlova", .Country = "Austria", .City = "Graz", .UnitPrice = 21, .Quantity = 52})
        Add(New Product() With {.ProductName = "Longlife Tofu", .Country = "USA", .City = "Boise", .UnitPrice = 7.75, .Quantity = 120})
        Add(New Product() With {.ProductName = "Alice Mutton", .Country = "Mexico", .City = "México D.F.", .UnitPrice = 21, .Quantity = 15})
        Add(New Product() With {.ProductName = "Alice Mutton", .Country = "Canada", .City = "Tsawwassen", .UnitPrice = 44, .Quantity = 16})
    End Sub
End Class

using System.Collections.Generic;
using System.Collections.ObjectModel;

public class Product {
    public string ProductName { get; set; }
    public string Country { get; set; }
    public string City { get; set; }
    public double UnitPrice { get; set; }
    public int Quantity { get; set; }
}

public class ProductList : ObservableCollection<Product> {
    public ProductList()
        : base() {
        Add(new Product() { ProductName = "Chang", Country = "UK", City = "Cowes", UnitPrice = 19, Quantity = 10 });
        Add(new Product() { ProductName = "Gravad lax", Country = "Italy", City = "Reggio Emilia", UnitPrice = 12.5, Quantity = 16 });
        Add(new Product() { ProductName = "Ravioli Angelo", Country = "Brazil", City = "Rio de Janeiro", UnitPrice = 19, Quantity = 12 });
        Add(new Product() { ProductName = "Tarte au sucre", Country = "Germany", City = "QUICK-Stop", UnitPrice = 22, Quantity = 50 });
        Add(new Product() { ProductName = "Steeleye Stout", Country = "USA", City = "Reggio Emilia", UnitPrice = 18, Quantity = 20 });
        Add(new Product() { ProductName = "Pavlova", Country = "Austria", City = "Graz", UnitPrice = 21, Quantity = 52 });
        Add(new Product() { ProductName = "Longlife Tofu", Country = "USA", City = "Boise", UnitPrice = 7.75, Quantity = 120 });
        Add(new Product() { ProductName = "Alice Mutton", Country = "Mexico", City = "México D.F.", UnitPrice = 21, Quantity = 15 });
        Add(new Product() { ProductName = "Alice Mutton", Country = "Canada", City = "Tsawwassen", UnitPrice = 44, Quantity = 16 });
    }
}

using System.Windows;
using System.Windows.Input;
using DevExpress.Xpf.Grid;

namespace DXGrid_RowDoubleClick {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
            grid.ItemsSource = new ProductList();
        }

        private void grid_MouseDoubleClick(object sender, MouseButtonEventArgs e) {
            int rowHandle = tView.GetRowHandleByMouseEventArgs(e);
            if (rowHandle == GridControl.InvalidRowHandle) return;
            if(grid.IsGroupRowHandle(rowHandle))
                MessageBox.Show("A group row has been double clicked.", "Info");
            else
                MessageBox.Show("A data row has been double clicked.", "Info");
        }
    }
}