WPF MVVM popup with checkBox inside DataGrid no fire events

Question

Here is my goal (simplified) : Create a userControl to display readable bitField.

Exemple with value 0x3: want to display option1 (bit 1): enable, option2 (bit 2):enable, option3 (bit 3): disable ...

userControl behavior: if I click on this control, it's open a popup (like combobox) with checkBoxes which allow you to enable optionX (which will change the value and displayed text).

This is the source code I use for the UserControl view

The code behind for binding value

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using MyProg.ViewModels;

namespace MyProg.Views
{
    /// 
    /// Interaction logic for BitField.xaml
    /// 
    public partial class BitField : UserControl
    {
        internal vmBitField m_ViewModel;

        public BitField()
        {
            InitializeComponent();
            // Load the viewModel
            m_ViewModel = new vmBitField();
            LayoutRoot.DataContext = m_ViewModel;
            m_ViewModel.PropertyChanged += M_ViewModel_PropertyChanged;
        }

        private void M_ViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (e.PropertyName == "Value")
            {
                if(IntValue != m_ViewModel?.Value)
                    IntValue = (int)m_ViewModel.Value;
            }
        }

        /// 
        /// Gets or sets the value which is displayed
        /// 
        public int IntValue
        {
            get { return (int)GetValue(ValueProperty); }
            set { SetValue(ValueProperty, value);}
        }

        /// 
        /// Identified the Value dependency property
        /// 
        public static readonly DependencyProperty ValueProperty = DependencyProperty.Register("IntValue", typeof(int), typeof(BitField), new PropertyMetadata(0, OnIntValueSet));

        private static void OnIntValueSet(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ((BitField)d).m_ViewModel.Value = (uint?)(int)e.NewValue;
        }
    }
}

and the UserControl viewModel

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MyProg.MVVM;

namespace MyProg.ViewModels
{
    class vmBitField : ViewModelBase
    {
        #region Members
        protected uint m_Value = 0; // 7
        #endregion

        #region Properties
        public uint? Value { get { return m_Value; } set { if (value != m_Value) { m_Value = (uint)value; RaiseEventPropertyChanged("Option1"); RaiseEventPropertyChanged("Option2"); RaiseEventPropertyChanged("Option3"); RaiseEventPropertyChanged("Text"); } } }
        public bool Option1 { get {return (Value & 0x1) == 1; } set { if (value != Option1) { m_Value ^= 0x1; RaiseEventPropertyChanged("Option1"); RaiseEventPropertyChanged("Value"); RaiseEventPropertyChanged("Text"); } } }
        public bool Option2 { get { return (Value & 0x2) == 1; } set { if (value != Option2) { m_Value ^= 0x2; RaiseEventPropertyChanged("Option2"); RaiseEventPropertyChanged("Value"); RaiseEventPropertyChanged("Text"); } } }
        public bool Option3 { get { return (Value & 0x4) == 1; } set { if (value != Option3) { m_Value ^= 0x4; RaiseEventPropertyChanged("Option3"); RaiseEventPropertyChanged("Value"); RaiseEventPropertyChanged("Text"); } } }
        public string Text { get { return "Option1:" + Option1 + " Option2:" + Option2 + " Option3:" + Option3; } }
        #endregion

        #region Contructors
        public vmBitField()
        {
        }
        #endregion

        #region Methodes
        #endregion
    }
}

This works correctly when I insert this userControl in a page or windows.

Now, I have a list with lot of bitfield. I want to display all of this in a datagrid. So I want to insert this userControl in a dataGrid. This is the code to add the datagrid

When my usercontrol is in a datagrid, when I click on togglebuton, it's open the popup correctly, but then I can't interact (check or uncheck) with any of checkBoxes inside the popup.

Anyone could help me to find why checkboxes inside a popup doesn't fired event ? I could add more info if needed.

Best Regards JM

Raviraj Palvankar · Accepted Answer

You will have to set the FocusManager.IsFocusScope of the popup to true. You can also set the cell's IsFocussable property through a style setter.

The problem why it does not let you edit anything on the popup is because the cell editing has not ended. Hence, you can also do the following by registering to the DataGrid_CellEditEnding event.

private static void DataGrid_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
{
    if (e.Column.GetType() == typeof(DataGridTemplateColumn))
    {
        var popup = GetVisualChild(e.EditingElement);
        if (popup != null && popup.IsOpen)
        {
            e.Cancel = true;
        }
    }   
}

WPF MVVM popup with checkBox inside DataGrid no fire events

Answers (1)

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