Xceed DataGrid set to row:MultiSelect - How to bind selected row to its MVVM row data

Question

I'm using Xceed DataGridControl in selection mode set to "Extended" (multi selection).

I'm using MVVM. Each row is bound to an instance of my class MyRowObject. MyRowObject has a boolean property "IsSelected". I want to bind a DataGridControl row "IsSelected" property (if any, I can't find one that is read/write) to my MyRowObject.IsSelected.

Does anyone know if it is possible to do it with Xceed DataGridControl and how to do it? If there is no direct binding possible, does anyone has written a behavior for this?

Please check this post helps you http://stackoverflow.com/questions/1631543/how-do-i-detect-row-selection-in-the-xceed-datagrid-for-wpf — user1386121, Apr 21 '16 at 15:20
Thanks, The link is about single selection. it works fine for single selection. The problem I have is about multi selection for which you should bind per row and IsSelected could only be read, there is no setter for that property (that I know). — Eric Ouellet, Apr 21 '16 at 15:39

Eric Ouellet · Accepted Answer · 2016-04-26T14:19:51.823

Actually this is not possible to do that directly. That is true for any version up to now (2016-04-25).

But Xceed was kind enough to give me the code to accomplish the same behavior (see below). I slightly modified their code in order to put it bi-directional and prevent an Exception but otherwise the behavior is exactly what I was looking for. Please note that it is hard coded to the property "IsSelected".

Instead of using: DataGridControl, use: DataGridControlCustom.

using System;
using System.ComponentModel;
using System.Reflection;
using System.Windows;
using Xceed.Wpf.DataGrid;

namespace XceedUtil
{
    public class DataGridControlCustom : DataGridControl
    {
        public DataGridControlCustom()
        {
            SelectionChanged += OnSelectionChanged;
        }

        private void OnSelectionChanged(object sender, DataGridSelectionChangedEventArgs e)
        {
            foreach (SelectionInfo selectionInfo in e.SelectionInfos)
            {
                foreach (var item in selectionInfo.AddedItems)
                {
                    PropertyInfo pi = item.GetType().GetProperty("IsSelected", BindingFlags.Public | BindingFlags.Instance);
                    if (pi != null && pi.CanWrite)
                    {
                        pi.SetValue(item, true);
                    }
                }
                foreach (var item in selectionInfo.RemovedItems)
                {
                    PropertyInfo pi = item.GetType().GetProperty("IsSelected", BindingFlags.Public | BindingFlags.Instance);
                    if (pi != null && pi.CanWrite)
                    {
                        pi.SetValue(item, false);
                    }
                }
            }
        }

        protected override DependencyObject GetContainerForItemOverride()
        {
            return new CustomDataRow();
        }
    }

    public class CustomDataRow : DataRow, IWeakEventListener
    {
        protected override void PrepareContainer(DataGridContext dataGridContext, object item)
        {
            base.PrepareContainer(dataGridContext, item);

            PropertyInfo pi = item.GetType().GetProperty("IsSelected", BindingFlags.Public | BindingFlags.Instance);
            if (pi != null && pi.CanWrite)
            {
                if ((bool)pi.GetValue(item) == true)
                {
                    dataGridContext.SelectedItems.Add(item);
                }
            }

            PropertyChangedEventManager.AddListener(item as INotifyPropertyChanged, this, "IsSelected");
        }

        private void UpdateSelectedItems(object item)
        {
            var selectedItems = DataGridControl.GetDataGridContext(this).SelectedItems;
            try
            {
                PropertyInfo pi = item.GetType().GetProperty("IsSelected", BindingFlags.Public | BindingFlags.Instance);
                if (pi != null && pi.CanWrite)
                {
                    if ((bool) pi.GetValue(item) == true)
                    {
                        selectedItems.Add(item);
                    }
                    else
                    {
                        selectedItems.Remove(item);
                    }
                }
            }
            catch (InvalidOperationException ex)
            {

            }
        }

        protected override void ClearContainer()
        {
            var item = this.DataContext;
            PropertyChangedEventManager.RemoveListener(item as INotifyPropertyChanged, this, "IsSelected");

            var selectedItems = DataGridControl.GetDataGridContext(this).SelectedItems.Remove(item);

            base.ClearContainer();
        }

        bool IWeakEventListener.ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
        {
            if (managerType == typeof(PropertyChangedEventManager))
            {
                this.UpdateSelectedItems(sender);
            }

            return true;
        }
    }
}

we are going to implement this, have you seen any issues with this approach? — phabtar, Aug 23 '18 at 06:44

Xceed DataGrid set to row:MultiSelect - How to bind selected row to its MVVM row data

1 Answers1