gistfile1.cs

// System.Net.Http.HttpClient でテスト
private async void OnTest1ButtonClicked(object sender, RoutedEventArgs e)
{
    System.Diagnostics.Debug.WriteLine("========== System.Net.Http.HttpClient test start  ==========");
    var sw = new System.Diagnostics.Stopwatch();
    sw.Start();

    await GetImage1("http://flashair/DCIM/101NIKON/DSCN0558.JPG", "DSCN0558.JPG");

    sw.Stop();
    System.Diagnostics.Debug.WriteLine(sw.Elapsed);
    System.Diagnostics.Debug.WriteLine("========== System.Net.Http.HttpClient test end    ==========");
}

private async Task<bool> GetImage1(string uri, string fileName)
{
    var req = new System.Net.Http.HttpClient();
    var res = await req.GetAsync(uri);
    if (res.IsSuccessStatusCode)
    {
        var folder = await Windows.Storage.KnownFolders.PicturesLibrary.CreateFolderAsync("FlashAir", CreationCollisionOption.OpenIfExists);
        if (null == folder) return false;
        var file = await folder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);

        using (var src = await res.Content.ReadAsStreamAsync())
        using (var dst = await file.OpenStreamForWriteAsync())
        {
            var read = 0;
            var size = 4096;
            var buffer = new byte[size];
            while ((read = src.Read(buffer, 0, size)) > 0)
            {
                dst.Write(buffer, 0, read);
            }
        }

        return true;
    }

    return false;
}


// Windows.Web.Http.HttpClient でテスト
private async void OnTest2ButtonClicked(object sender, RoutedEventArgs e)
{
    System.Diagnostics.Debug.WriteLine("========== Windows.Web.Http.HttpClient test start ==========");
    var sw = new System.Diagnostics.Stopwatch();
    sw.Start();

    await GetImage2("http://flashair/DCIM/101NIKON/DSCN0557.JPG", "DSCN0571.JPG");

    sw.Stop();
    System.Diagnostics.Debug.WriteLine(sw.Elapsed);
    System.Diagnostics.Debug.WriteLine("========== Windows.Web.Http.HttpClient test end   ==========");
}

private async Task<bool> GetImage2(string uri, string fileName)
{

    var req = new Windows.Web.Http.HttpClient();
    var res = await req.GetAsync(new Uri(uri, UriKind.Absolute));
    if (res.IsSuccessStatusCode)
    {
        var folder = await Windows.Storage.KnownFolders.PicturesLibrary.CreateFolderAsync("FlashAir", CreationCollisionOption.OpenIfExists);
        if (null == folder) return false;
        var file = await folder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);

        using (var src = (await res.Content.ReadAsInputStreamAsync()).AsStreamForRead())
        using (var dst = await file.OpenStreamForWriteAsync())
        {
            var read = 0;
            var size = 4096;
            var buffer = new byte[size];
            while ((read = src.Read(buffer, 0, size)) > 0)
            {
                dst.Write(buffer, 0, read);
            }
        }

        return true;
    }

    return false;
}