How do I use the new HttpClient from Windows.Web.Http to download an image?

Question

Using Windows.Web.Http.HttpClient how can I download an image? I would like use this HttpClient because it is available to use in portable class libraries.

Answer 1

This is what I eventually came up with. There is not much documentation around Windows.Web.Http.HttpClient and a lot of the examples online use old mechanisms like ReadAllBytesAsync which are not available with this HttpClient.

I should note that this question from MSDN helped me out a lot, so thanks to that person. As the comment over there states, this guy must be the only person in the world who knows about Windows.Web.Http!

using System;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Threading.Tasks;
using System.Windows.Media.Imaging;
using Windows.Storage.Streams;
using Windows.Web.Http;

public class ImageLoader
{
    public async static Task<BitmapImage> LoadImage(Uri uri)
    {
        BitmapImage bitmapImage = new BitmapImage();

        try
        {
            using (HttpClient client = new HttpClient())
            {
                using (var response = await client.GetAsync(uri))
                {
                    response.EnsureSuccessStatusCode();

                    using (IInputStream inputStream = await response.Content.ReadAsInputStreamAsync())
                    {
                        bitmapImage.SetSource(inputStream.AsStreamForRead());
                    }
                }
            }
            return bitmapImage;
        }
        catch (Exception ex)
        {
            Debug.WriteLine("Failed to load the image: {0}", ex.Message);
        }

        return null;
    }
}

Answer 2

public async void downLoadImage(string url)
{
        using (var client = new HttpClient())
        {
            var response = client.GetAsync(url).Result;
            BitmapImage bitmap = new BitmapImage();
            if (response != null && response.StatusCode == HttpStatusCode.OK)
            {
                using (var stream = await response.Content.ReadAsStreamAsync())
                {
                    using (var memStream = new MemoryStream())
                    {
                        await stream.CopyToAsync(memStream);
                        memStream.Position = 0;
                        bitmap.SetSource(memStream.AsRandomAccessStream());
                    }
                }
                HardcodedValues.profilePic = bitmap;
            }
        }
}

Answer 3

In .net core web api you can use the below code

[Route("getProductImage/v1")]
    [HttpGet]
    public async Task<IActionResult> getProductImage(GetProductImageQueryParam parammodel)
    {
        using (HttpClient client = new HttpClient())
        {
            MNimg_URL = MNimg_URL + parammodel.modelname;
            HttpResponseMessage response = await client.GetAsync(MNimg_URL);
            byte[] content = await response.Content.ReadAsByteArrayAsync();
            //return "data:image/png;base64," + Convert.ToBase64String(content);
            return File(content, "image/png", parammodel.modelname);
        }
    }

here GetProductImageQueryParam is a class with input parameters

Answer 4

Updated for 8.1 - 10.

    public async static Task<BitmapImage> LoadImage(Uri uri)
    {
        BitmapImage bitmapImage = new BitmapImage();

        try
        {
            using (Windows.Web.Http.HttpClient client = new Windows.Web.Http.HttpClient())
            {
                using (var response = await client.GetAsync(uri))
                {
                    response.EnsureSuccessStatusCode();

                    using (MemoryStream inputStream = new MemoryStream())
                    {
                        await inputStream.CopyToAsync(inputStream);
                        bitmapImage.SetSource(inputStream.AsRandomAccessStream());
                    }
                }
            }
            return bitmapImage;
        }
        catch (Exception ex)
        {
            Debug.WriteLine("Failed to load the image: {0}", ex.Message);
        }

        return null;
    }