CODEWITHSUNDEEP
wpfmvvmwpfdatagridcollectionviewsource
char m
char m

Reputation: 8336

how to turn off (with a checkbox) WPF/MVVM DataGrid grouping that is implemented using CollectionViewSource?

I have working implementation of datagrid grouping. Below is what i do (GroupStyle with expander omitted):

<CollectionViewSource x:Key="SelectedObjectsViewSource" Source="{Binding SelectedObjectItems}">
    <CollectionViewSource.GroupDescriptions>
       <PropertyGroupDescription PropertyName="TableId"/>
    </CollectionViewSource.GroupDescriptions>
</CollectionViewSource>


<DataGrid Name="SelectedObjectsGrid" 
     ItemsSource="{Binding Source={StaticResource SelectedObjectsViewSource}}"
     SelectionMode="Extended"
     CanUserAddRows="False"
     AutoGenerateColumns="False">

I would like to add a checkbox that user can turn off/on grouping. But i have no idea how to implement this in MVVM

Upvotes: 3

Views: 1046

Answers (2)

Alessandro Rossi
Alessandro Rossi

Reputation: 2450

I advise you to bind the checkbox to a bool property of the viewmodel where its setter also sets the grouping status of the collectionview following the assigned value. Like in the following sample: where the bool property bound to the checkbox status is GroupView and the collection bound to the datagrid is View.

C# ViewModel

class ViewModel : INotifyPropertyChanged {
    public event PropertyChangedEventHandler PropertyChanged;
    protected void NotifyPropertyChanged(string info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }

    private ICollectionView _View;
    public ICollectionView View
    {
        get
        {
            return _View;
        }
        set
        {
            _View = View;
            NotifyPropertyChanged("View");
        }
    }

    private bool _GroupView;
    public bool GroupView
    {
        get
        {
            return _GroupView;
        }
        set
        {
            if (value != _GroupView)
            {
                // Clear Grouping status of the view
                View.GroupDescriptions.Clear();
                if (value)
                {
                    // If true set Grouping status
                    View.GroupDescriptions.Add(new PropertyGroupDescription("TableId"));
                }
                _GroupView = value;
                NotifyPropertyChanged("GroupView");

                // Notify the UI that also the View changed in order to redraw the datagrid with or without grouping
                NotifyPropertyChanged("View");
            }
        }
    }   
}

C# Code Behind

public partial class MyWindow : Window
{
    public MyWindow()
    {
        InitializeComponent();
        ViewModel myViewModel = new ViewModel();
        myViewModel.View = .....;
        DataContext = myViewModel;

    }
}

XAML

<StackPanel>
    <CheckBox IsChecked="{Binding GroupView, Mode=TwoWay}"/>
    <DataGrid Name="SelectedObjectsGrid" 
            ItemsSource="{Binding View, Mode=TwoWay}"
            SelectionMode="Extended"
            CanUserAddRows="False"
            AutoGenerateColumns="False"/>
</StackPanel>

Upvotes: 2

Yury Polubinsky
Yury Polubinsky

Reputation: 373

You can create another DataGrid in current View:

<DataGrid Name="SelectedObjectsGridWithoutGrouping" Visibility="False" 
 ItemsSource="{Binding NewCollection}"
 SelectionMode="Extended"
 CanUserAddRows="False"
 AutoGenerateColumns="False">

After that, you must create NewCollection in ViewModel (which contains your items from SelectedObjectItems collection, but without grouping) and when user changes the checkbox, showing or hiding one of them by changing Visibility SelectedObjectsGrid or SelectedObjectsGridWithoutGrouping.

Upvotes: 0

Related Questions