WP8.1 C# Binding Contact Image

Question

Information
Quite simply, I’m attempting to create an app that would display the contacts for a user.

I’m also a self-taught programmer, so I

Answer 1

you can do one thing ..

you can retrieve all the images from the contacts class and store them in an array or stack or List of BitmapImages .. (*** i think list would be an better option )

Contact c = value as Contact; foreach(var p in c) { q.Add(p.Thumbnail); }

here q is an list of bitmapmages

Answer 2

    public static BitmapImage GetImage(Contact con)
    {
        if (con == null || con.Thumbnail == null)
        {
            return null;
        }

        var bitmapImage = new BitmapImage();
        bitmapImage.DecodePixelHeight = 256;
        bitmapImage.DecodePixelWidth = 256;


        Action load = async () =>
        {
            using (IRandomAccessStream fileStream = await con.Thumbnail.OpenReadAsync())
            {
                await bitmapImage.SetSourceAsync(fileStream);
            }
        };

        load();

        return bitmapImage;
    }

Answer 3

The problem is that the GetImage method is asynchronous, so you need to wait for the result to complete:

        Task<BitmapImage> getImageTask = GetImage(c);
        getImageTask.RunSynchronously();
        return getImageTask.Result;

Answer 4

Thanks to Romasz and Murven, I was able to get a solution for my problem.

XAML:

<ListView x:Name="ContactsView" Grid.Row="1" Background="White" ItemsSource="{Binding}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <Image x:Name="ContactImage" DataContext="{Binding Converter={StaticResource ContactPictureConverter}}" Source="{Binding Result}" Height="100" Width="100" Margin="0,0,0,0"/>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

Converter:

using Nito.AsyncEx;

public class ContactPictureConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        try
        {
            Contact c = value as Contact;
            return NotifyTaskCompletion.Create<BitmapImage>(GetImage(c));
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex.Message);
            return null;
        }
    }

    private async Task<BitmapImage> GetImage(Contact con)
    {
        using (var stream = await con.Thumbnail.OpenReadAsync())
        {
            BitmapImage image = new BitmapImage();
            image.DecodePixelHeight = 100;
            image.DecodePixelWidth = 100;

            image.SetSource(stream);
            return image;
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, string culture)
    {
        throw new NotImplementedException();
    }
}

Packages:
Nito.AsyncEx from Nuget