Question

I wan’t to know the best method to load image asynchronously from Mysql in a WPF application.

Thanks.

Answer 1

Use the ThreadPool to load the image from the database.

• On the ThreadPool, queue the load of the image from the database;

• When the image is loaded, still in the thread pool, convert the image into an ImageSource using BitmapFrame.Create();

• Using Dispather.Invoke, set the Image property to the loaded image.

So, something like this:

private void button1_Click(object sender, RoutedEventArgs e)
{
    ThreadPool.QueueUserWorkItem(LoadImage, new LoadImageRequest { ImageName = "Image.png", Control = image1 });
}

private void LoadImage(object state)
{
    var request = (LoadImageRequest)state;

    byte[] data = ...; // load bytes from the database using request.ImageName

    using (var stream = new MemoryStream(data))
    {
        var imageSource = BitmapFrame.Create(stream);

        Dispatcher.BeginInvoke(
            new Action<ImageSource>(p => request.Control.Source = p), imageSource
        );
    }
}

private class LoadImageRequest
{
    public string ImageName;
    public Image Control;
}