Question

I am developing a control in WPF, my control contains some other WPF controls such as labels, buttons and one DataGrid. So, what I have been trying to do is to create a dependency property that allows me to get the DataSource for my dataGrid from the outside of my container control.

So far I have this code:

public static readonly DependencyProperty dataSourceProperty = DependencyProperty.Register(
                                                                            "DataSource",
                                                                            typeof(object),
                                                                            typeof(MyCustomControl));
    public object DataSource
    {
        get
        {
            return (object)GetValue(dataSourceProperty);
        }
        set
        {
            SetValue(dataSourceProperty, value);
        }
    }

But what I cant figure out is where I have to write this code:

    myDataGrid.ItemsSource = DataSource;

I mean, what I need is, in my xaml file, be able to do this:

<MyCustomControl Name="MyControl" DataSource={Binding MyData}/>

I hope you can help me. Thank you in advance.

Answer 1

After some hours of research I’ve found the solution to my problem:

Since I needed to have access to a nested control dependency property from the container control I did this:

public static readonly DependencyProperty itemsSourceProperty = ItemsControl.ItemsSourceProperty.AddOwner(
                                                                        typeof(MyCustomControl), 
                                                                        new FrameworkPropertyMetadata(
                                                                            ItemsSourcePropertyChangedCallback));

    public System.Collections.IEnumerable ItemsSource
    {
        get
        { return (System.Collections.IEnumerable)GetValue(itemsSourceProperty); }

        set
        { SetValue(itemsSourceProperty, value); }
    }

    private static void ItemsSourcePropertyChangedCallback(DependencyObject controlInstance, DependencyPropertyChangedEventArgs args)
    {
        MyCustomControlraceUIGridControlInstance = (MyCustomControl)controlInstance;  
        raceUIGridControlInstance.extendedDataGrid.ItemsSource = (System.Collections.IEnumerable)args.NewValue;            
    }

After doing that you can write in you XAML:

<MyCustomControl Name=mycustomControl ItemsSource="{Binding YourData}" />

You can do this with any nested control dependency property.