ObservableCollection with INotifyPropertyChanged into DatagridComboboxColumn Binding

问题

My little project looks now quite different. Now I have ObservableCollection PackagesList with data which I want to bind with whole DataGrid (via Binding Path) and ObservableCollection DestinationItememsSource where I store cases for DataGridComboboxColumn (as ItemsSourceBinding). SelectedItem property in DatagridComboboxColumn is one value from PackageInfo (and it is one of DestinationNames cases ofc). Binding on DatagridTextBoxColumns is ok.

XAML:

<Window x:Class="test01.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="300" Width="400" Loaded="Window_Loaded">
    <Grid>
        <Border x:Name="mainBorder" Margin="20">
            <DataGrid x:Name="mainDataGrid" x:Uid="mainDataGrid" AutoGenerateColumns="False"
                       AlternationCount="2" SelectionMode="Single" HorizontalAlignment="Stretch">
                <DataGrid.Columns>
                    <DataGridTextColumn Binding="{Binding Path=id}"
                                    Header="ID" Width="Auto" IsReadOnly="True"/>
                    <DataGridTextColumn Binding="{Binding Path=name}"
                                    Header="Name" Width="Auto" IsReadOnly="True"/>
                    <DataGridTextColumn Binding="{Binding Path=quantity}"
                                    Header="Quantity" Width="Auto" IsReadOnly="True"/>
                    <DataGridTextColumn Binding="{Binding Path=price}"
                                    Header="Price" Width="Auto" IsReadOnly="True"/>
                    <DataGridComboBoxColumn ItemsSource="{Binding DestinationItemsSource}" 
                                                    SelectedItemBinding="{Binding Path=destination, UpdateSourceTrigger=PropertyChanged}"
                                                    Header="Destination" Width="Auto"/>
                </DataGrid.Columns>
            </DataGrid>
        </Border>
    </Grid>
</Window>

C#:

public class PackageInfo
    {
        public int id { get; set; }
        public string name { get; set; }
        public int quantity { get; set; }
        public double price { get; set; }
        public string destination { get; set; }
    }

    public class DestinationNames : INotifyPropertyChanged
    {
        public string name { get; set; }

        public event PropertyChangedEventHandler PropertyChanged;

        public DestinationNames(string value)
        {
            this.name = value;
        }

        public string DestinationName
        {
            get { return name; }
            set
            {
                name = value;
                OnPropertyChanged("DestinationName");
            }
        }

        protected void OnPropertyChanged(string name)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(name));
            }
        }
    }


    public partial class MainWindow : Window
    {
        public ObservableCollection<DestinationNames> DestinationItememsSource { get; set; }
        public ObservableCollection<PackageInfo> PackagesList { get; set; }

        public MainWindow()
        {
            InitializeComponent();
        }

        public void Window_Loaded(object sender, RoutedEventArgs e)
        {
            LoadPackages();
        }

        public void LoadPackages()
        {
            DestinationItememsSource = new ObservableCollection<DestinationNames>();
            DestinationItememsSource.Add(new DestinationNames("London"));
            DestinationItememsSource.Add(new DestinationNames("Plymouth"));
            DestinationItememsSource.Add(new DestinationNames("Birmingham"));
            DestinationItememsSource.Add(new DestinationNames("Cambridge"));

            PackagesList = new ObservableCollection<PackageInfo>();
            PackagesList.Add(new PackageInfo { id = 1, name = "Potato", quantity = 3, price = 2.2, destination = "London" });
            PackagesList.Add(new PackageInfo { id = 2, name = "Tomato", quantity = 5, price = 3.8, destination = "Plymouth" });
            PackagesList.Add(new PackageInfo { id = 3, name = "Carrot", quantity = 1, price = 5.1, destination = "London" });
            PackagesList.Add(new PackageInfo { id = 4, name = "Pea", quantity = 6, price = 1.8, destination = "Plymouth" });
            PackagesList.Add(new PackageInfo { id = 5, name = "Bean", quantity = 2, price = 1.5, destination = "Birmingham" });
            mainDataGrid.ItemsSource = PackagesList;
        }
    }

How to bind this DatagridComboboxColumn properly? Should I use INotifyCollectionChanged ?? What if I want to all data in datagrid will be automatically synced with ObservableCollection ?? Please help with some example.

回答1:

Have PackageInfo implement INotifyPropertyChanged.

An ObservableCollection automatically implements INotifyCollectionChanged.

You will need to add List or ObservableCollection Destinations as a property of PackageInfo
NO class DestinationNames
Just a class DestinationName

回答2:

Your binding to DestinationItememsSource does not work, because it isnt part of the PackageInfo object. You also cant bind to the Windows DataContext via FindAncestor or ElementName-binding because DataGrid-Columns wont be added to the visual tree.

One solution I can think of is using the CollectionViewSource:

<Window.Resources>
    <CollectionViewSource Source="{Binding RelativeSource={RelativeSource Self}, Path=DestinationItememsSource}" x:Key="destinations">
        <!--here you can also add Group and SortDescriptions-->
    </CollectionViewSource>
</Window.Resources>
<DataGridComboBoxColumn ItemsSource="{Binding Source={StaticResource ResourceKey=destinations}}".../> 

I cant test it atm, because I'm still downloading VS 2012.^^

Anotherone would be to simply add a List of Destinations to your PackageInfo object (but this would cause a lot of redundancies).

来源：https://stackoverflow.com/questions/15883062/observablecollection-with-inotifypropertychanged-into-datagridcomboboxcolumn-bin