views:

49

answers:

1

I am having a problem displaying an image with a web URL in a WPF user control. I have worked through all the suggestions for a similar problem asked on this site in Aug 2008 (http://stackoverflow.com/questions/20586/wpf-image-urisource-and-data-binding) but none of those suggestions have worked.

What I'd like to do is:

<Image Width="50" Name="MemberImage">
    <Image.Source>
        <BitmapImage DecodePixelWidth="50" UriSource="{Binding Member.ImageFilePathUri}" />
    </Image.Source>
</Image>

ImageFilePathUri is a Uri created from the string path through:

public Uri ImageFilePathUri
    {
        get
        {
            return new Uri(this.ImageFilePath);
        }
    }
}

This gives the "Property 'UriSource' or property 'StreamSource' must be set." error as expected.

I have also tried using a value converter:

public class ImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        var image = new BitmapImage();
        image.BeginInit();
        if (value != null)
        {
            image.UriSource = new Uri((string)value);
        }
        image.DecodePixelWidth = 50;
        image.EndInit();
        return image;
    }
}

However, binding to it using:

<Image Name="TestImage" Width="50" Source="{Binding Path=Member.ImageFilePath, Converter=Parliament.HansardApplicationSuite.Logging.Helpers.ImageConverter}"></Image>

doesn't display the image.

A further attempt to load the image programmatically, in the control constructor and/or the control Loaded event have also not worked:

if (this.MemberRollItemViewModel.Member != null)
{
    var image = new BitmapImage();
    image.BeginInit();
    image.UriSource = new Uri(this.MemberRollItemViewModel.Member.ImageFilePath);
    image.DecodePixelWidth = 50;
    image.EndInit();

    this.MemberImage.Source = image;
}

The one thing that has worked is saving the image to a local file path and displaying that:

<Image Width="50" Name="MemberImage">
    <Image.Source>
        <BitmapImage DecodePixelWidth="50" UriSource="C:\Data\6bc64e7b-2df5-40d5-b6c4-eaf732318222.jpg" />
    </Image.Source>
</Image>

This is obviously only useful in debugging the problem and is not a solution. The same code but substituting the http address for the local file path doesn't work.

<Image.Source>
    <BitmapImage DecodePixelWidth="50" UriSource="http://member.org/6bc64e7b-2df5-40d5-b6c4-eaf732318222.jpg" />
</Image.Source>

Update:

This is the MemberImage property implementation.

public BitmapImage MemberImage
{
    get
    {
        var image = new BitmapImage();

        if (this.Member != null)
        {
            WebRequest request = WebRequest.Create(new Uri(this.Member.ImageFilePath, UriKind.Absolute));
            request.Timeout = -1;
            WebResponse response = request.GetResponse();
            Stream responseStream = response.GetResponseStream();
            BinaryReader reader = new BinaryReader(responseStream);
            MemoryStream memoryStream = new MemoryStream();

            byte[] bytebuffer = new byte[BytesToRead];
            int bytesRead = reader.Read(bytebuffer, 0, BytesToRead);

            while (bytesRead > 0)
            {
                memoryStream.Write(bytebuffer, 0, bytesRead);
                bytesRead = reader.Read(bytebuffer, 0, BytesToRead);
            }

            image.BeginInit();
            memoryStream.Seek(0, SeekOrigin.Begin);

            image.StreamSource = memoryStream;
            image.EndInit();
        }

        return image;
    }
}

Update:

This is how I am binding to the control in my view:

<Image Width="50" Source="{Binding MemberImage}" />

MemberImage is the property I have given above. My data context is being set correctly because that property is being run, it's just not returning an image.

A: 

WebURL can't be provided as a source to UriSource property of BitmapImage. If it is weburl you need to download that image locally and bind that path to UriSource. See the below

http://blogs.windowsclient.net/cennest/archive/2010/03/26/code-for-keeps-wpf-silverlight-retrieve-images-from-db-url.aspx

Update:

void MainWindow_Loaded(object sender, RoutedEventArgs e)
    {
        var image = new BitmapImage();
        int BytesToRead=100;

        WebRequest request = WebRequest.Create(new Uri("http://www.interweb.in/attachments/pc-wallpapers/16187d1222942178-nature-wallpaper-nature-summer-wallpaper.jpg", UriKind.Absolute));
        request.Timeout = -1;
        WebResponse response = request.GetResponse();
        Stream responseStream = response.GetResponseStream();
        BinaryReader reader = new BinaryReader(responseStream);
        MemoryStream memoryStream = new MemoryStream();

        byte[] bytebuffer = new byte[BytesToRead];
        int bytesRead = reader.Read(bytebuffer, 0, BytesToRead);

        while (bytesRead > 0)
        {
            memoryStream.Write(bytebuffer, 0, bytesRead);
            bytesRead = reader.Read(bytebuffer, 0, BytesToRead);
        }

        image.BeginInit();
        memoryStream.Seek(0, SeekOrigin.Begin);

        image.StreamSource = memoryStream;
        image.EndInit();

        myImage.Source = image;
    }
Ragunathan
Rag, thanks for the link. I have tried implementing that by creating a property, MemberImage, returning a BitmapImage using the example in the blog and then binding my Image.Source to that property but it still doesn't display.<Image Width="50" Source="{Binding MemberImage}" />Does this mean I need to save the image first and then bind to that file path?
Val M
No it will just work. Can you post the MemberImage property code?
Ragunathan
I have updated my original question with the MemberImage implementation. This still isn't working, just not returning any image.
Val M
I tried the same code using Window loaded event. It works fine. Please see the code in my answer. I am thinking problem will be related to your binding to View.
Ragunathan
I can't see any difference between your code and mine (apart from your reading 100 bytes while I'm reading 100 000. Surely not an important difference? I have added the binding from my XAML to my question.
Val M
Fixed! It was the network credentials that were missing. Explicitly setting them now works:request.Credentials = CredentialCache.DefaultNetworkCredentials;Thanks for the help!
Val M