列表框中的复选框以选择多个项目，并使用MVVM将其添加到另一个列表框中

Question

Using MVVM,

I have two listboxes which contains Checkboxes and data is binded from database.

The Items which are checked in first Listbox want to add it in Second listbox.

First ListBox:

 <pmControls:pmListBox SelectionMode="Multiple" Grid.Row="1" Margin="3" ItemsSource="{Binding ParcelFacilities}" >

            <interactivity:Interaction.Triggers>
                <interactivity:EventTrigger EventName="SelectionChanged">
                    <shared:EventToCommandTrigger Command="{Binding Listbox_SelectionChangeCommand}" />
                </interactivity:EventTrigger>
            </interactivity:Interaction.Triggers>


            <pmControls:pmListBox.ItemTemplate >
                <DataTemplate >
                    <pmControls:pmCheckBox  Content="{Binding Title}" Margin="3" Width="200"  IsChecked="{Binding checkedParcelFacility}" >

                    </pmControls:pmCheckBox>

                </DataTemplate>
            </pmControls:pmListBox.ItemTemplate>

Second ListBox:

 <pmControls:pmListBox SelectionMode="Multiple"   Grid.Row="1" Margin="3" ItemsSource="{Binding Selected_ParcelFacilities}" 
                                   Height="100">

            <pmControls:pmListBox.ItemTemplate >
                <DataTemplate >

                    <pmControls:pmCheckBox Content="{Binding Title}" Margin="3" Width="200" ></pmControls:pmCheckBox>

                </DataTemplate>
            </pmControls:pmListBox.ItemTemplate>

In ViewMOdel:

I have handled SelectionChanged Event For first Listbox and tryied to add checked element to the collection Named as Selected_ParcelFacilities and Binded it to Second Listbox.

         public ParcelViewModel(IModalDialogService modalDialogService, IMessageBoxService messageBoxService)
     {       

            parcelFacilities = new ObservableCollection<Parcel_Facility>();

            Selected_ParcelFacilities = new ObservableCollection<Parcel_Facility>();

            Selected_ParcelFacilities.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler(Selected_ParcelFacilities_CollectionChanged);
  }


 void Selected_ParcelFacilities_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
 {
     OnPropertyChanged("Selected_ParcelFacilities");
 }

private void Executelistbox_SelectionChangeCommand(EventToCommandArgs args)
 {

     bool a = checkedParcelFacility;

     foreach (Parcel_Facility item in parcelFacilities)
     {

                if (Selected_ParcelFacilities != null)
                {
                    Selected_ParcelFacilities.Add(item);
                }                    
     }             
 }

But using above code all items from first listbox are adding to second , i am not getting how to check wheather its cheked or not.

Please Help.

Answer 1

you can simply bind your second list box to SelectedItems of your first one. this would work with real selection in listbox first.

<ListBox x:Name="second" ItemsSource="{Binding Elementname=first, Path=SelectedItems, Mode=OneWay}"/>

another approach is to use a ICollectionView with filter for your second listbox. the filter simply handle the checkedParcelFacility Property and the second listbox is bind to the ICollectionView.