如何将WPF / MVVM应用程序中ListView + GridView中的单个复选框状态绑定到集合的属性

Question

I've read many topics that are really close to my question but none of them clarified me how to handle my problem.

In my WPF/MVVM app I have ListView in which there is GridView. I would like to have the first column as checkboxes. The ItemsSource of ListView is bind to MyItemsCollectionProperty (which is basically IEnumerable of MyClass instances). My ViewModel class has that property of course. I was able to bind all other columns from grid to properties of MyItemsCollectionProperty properties (I mean One, Two, Three) but not the checkbox column. So the question is how to bind my checkbox state directly to the property of MyClass in the collection (IsMarked boolean property)? I would appriciate any suggestions.

MyClass def:

namespace MyNamespace
{
    public class MyClass
    {
        public bool IsMarked { get; set; }
        public string One { get; set; }
        public string Two { get; set; }
        public string Three { get; set; }
    }
}

And the XAML:

    <ListView x:Name="listView" HorizontalAlignment="Left" Height="375" Margin="24,82,0,0" VerticalAlignment="Top" Width="750" ItemsSource="{Binding MyItemsCollectionProperty}">
        <ListView.View>
            <GridView>
                <GridViewColumn Width="30">
                    <GridViewColumn.CellTemplate>
                        <DataTemplate>
                            <Grid>
                                <CheckBox x:Name="checkBoxSelect"/>
                            </Grid>
                        </DataTemplate>
                    </GridViewColumn.CellTemplate>
                    <Grid>
                        <CheckBox x:Name="checkBoxSelectAll" ToolTip="Select all" IsChecked="{Binding SelectedAll}" Command="{Binding SelectAllCmd}"/>
                    </Grid>
                </GridViewColumn>
                <GridViewColumn Header="One" DisplayMemberBinding="{Binding One}"/>
                <GridViewColumn Header="Two" DisplayMemberBinding="{Binding Two}"/>
                <GridViewColumn Header="Three" DisplayMemberBinding="{Binding Three}"/>
            </GridView>
        </ListView.View>
    </ListView>

And the piece of simplified ViewModel class code (not the whole class):

namespace MyNamespace.ViewModel
{
    public class MainWindowViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private IEnumerable<MyClass> _myItemsCollectionProperty;
        public IEnumerable<MyClass> MyItemsCollectionProperty
        {
            get { return _myItemsCollectionProperty; }
            set
            {
                _myItemsCollectionProperty = value;
                OnPropertyChanged(nameof(MyItemsCollectionProperty));
            }
        }

        //(...)

        [NotifyPropertyChangedInvocator]
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

Answer 1

You need to implement INotifyPropertyChanged in MyClass to enable binding.

Check here how to impleement it https://docs.microsoft.com/en-us/dotnet/framework/wpf/data/how-to-implement-property-change-notification

Answer 2

For those who will experience similar problem I have the solution (based on the XAMlMAX and partially Giltanas comments).

I am not sure if that is the best possible solution but what I've done is:

1. I left the MyClass almost as it was - I removed IsMarked property since it is strictly View-related - checkbox column (so I treat that class as it is strict Model class which instances are loaded by other Model class for loading them). No relation to View layer for now.
2. I created second class (let's call it MyClassVM) which is almost the same as MyClass. The difference is that this one has additional property IsMarked which is bound to checkbox column. Other difference is that this class implements INotifyPropertyChanged interface so it's strictly View-related.
3. There is async method in ViewModel for loading MyClass instance and then there is translantion from MyClass instance into MyClassVM. MyClassVM props are bound to the View.

Everything works as expected and I do believe I've got proper separation of BL (Model) and View/ViewModel. Correct me if I'm wrong. Thanks for all the suggestions. You guys helped a lot.

And funny but extremally important thing. What XAMlMAX suggested - after changes I've done I was given IntelliSense error in XAML but I ignored it and all the projects compiled and work as expected.