Develop Reference

Download Video File via video URL in windows phone 8.1 C#

I have tried to download video file from video URL. Video file created but downloading does not happen here. just 57KB file generate. My code is here.
public async void DownloadTrack(Uri SongUri, string fileName)
{
using (HttpClient httpClient = new HttpClient())
{
var data = await httpClient.GetByteArrayAsync(SongUri);
StorageFolder storageFolder = KnownFolders.VideosLibrary;
var file = await storageFolder.CreateFileAsync(fileName, CreationCollisionOption.GenerateUniqueName);
///////////////////
using (var targetStream = await file.OpenAsync(FileAccessMode.ReadWrite))
{
await targetStream.AsStreamForWrite().WriteAsync(data, 0, data.Length);
await targetStream.FlushAsync();
}
}
}
Here video file creates but does not file download. I want to download file. I searched much about this. here is accepted Stackoverflow answer link but this also does the same. Example
can you please provide any better solution.

Download and save a picture from a url Universal windows app

I am using the below code to downlaod the picture form a remote url and save to Local storage folder
try
{
var rootFolder = await ApplicationData.Current.LocalFolder.CreateFolderAsync( "MyAppName\\CoverPics", CreationCollisionOption.OpenIfExists);
var coverpic_file = await rootFolder.CreateFileAsync(filename, CreationCollisionOption.FailIfExists);
try
{
var httpWebRequest = HttpWebRequest.CreateHttp(coverUrl);
HttpWebResponse response = (HttpWebResponse)await httpWebRequest.GetResponseAsync();
Stream resStream = response.GetResponseStream();
using (var stream = await coverpic_file.OpenAsync(FileAccessMode.ReadWrite))
{
await resStream.CopyToAsync(stream.AsStreamForWrite());
}
response.Dispose();
}
catch //any exceptions happend while saving the picture
{
saved = false;
}
}
catch
{
//https://msdn.microsoft.com/en-us/library/windows/apps/br227250.aspx
//Raise an exception if file already present
saved = true;
}
This code is working for me in most of the cases , but i noticed that for few pictures the image is not downloading completely.
I am callling this function in an async block for more tahn 100 images in a single go inside the foreach loop and in the end few of them are failed downloads
[ Either i can see some invalid file is getting created
or part of image only in downloading and rest of the area i can see a black colour block [ looks like image is corrupted].
Size of all images is less than 1 MB only
Can some one help me to optimize this code or point out the mistake in code so i can able to download all the images completely

I am not seeing any error in my code. But after trying some different ways of downloading and saving a file my code looks like this and
try
{
HttpClient client = new HttpClient(); // Create HttpClient
byte[] buffer = await client.GetByteArrayAsync(coverUrl); // Download file
using (Stream stream = await coverpic_file.OpenStreamForWriteAsync())
stream.Write(buffer, 0, buffer.Length); // Save
}
catch
{
saved = false;
}
And this code is working fine without causing any issues All images are downloading completely and no more issues of black block on images.
If any one can points out the difference with my first code will be really helpful to understood the reason for error

Have you tried using new Windows.Web.Http.HttpClient instead of HttpWebRequest?
Also take a look this SO question :
How do I use the new HttpClient from Windows.Web.Http to download an image?
If you not familiar with HttpClient, I sugest to watch CH9 presentation :
https://channel9.msdn.com/Events/Build/2013/4-092

I tried your download and experienced the same issues.
var myFolder = await ApplicationData.Current.LocalFolder.CreateFolderAsync("MyFolderPath", CreationCollisionOption.OpenIfExists);
var myFile = await myFolder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
BackgroundDownloader downloader = new BackgroundDownloader();
DownloadOperation download = downloader.CreateDownload(new Uri(URL), myFile);
await download.StartAsync();

Download and Save image in Pictures Library through Windows 8 Metro XAML App

I am trying to develop a simple Windows 8 Metro app which simply downloads an image file from a given URL (say http://sample.com/foo.jpg) and then save it to Pictures Library.
I have an image control in the UI to display the downloaded image.
I'm also facing difficulty in setting the image source for the image control to the newly downloaded image (actually I'm not even able to download it).
Also, is it possible to store the image file in a particular folder in the Pictures library (if it doesn't exist, then the app should create it)?
I'm really stuck here.
Please help me.

Here's some rough code that I believe accomplishes what you want. It assumes you have two image controls (Image1 and Image2) and that you have the Pictures Library capability checked in the manifest. Take a look at the XAML images sample as well
Uri uri = new Uri("http://www.picsimages.net/photo/lebron-james/lebron-james_1312647633.jpg");
var fileName = Guid.NewGuid().ToString() + ".jpg";
// download pic
var bitmapImage = new BitmapImage();
var httpClient = new HttpClient();
var httpResponse = await httpClient.GetAsync(uri);
byte[] b = await httpResponse.Content.ReadAsByteArrayAsync();
// create a new in memory stream and datawriter
using (var stream = new InMemoryRandomAccessStream())
{
using (DataWriter dw = new DataWriter(stream))
{
// write the raw bytes and store
dw.WriteBytes(b);
await dw.StoreAsync();
// set the image source
stream.Seek(0);
bitmapImage.SetSource(stream);
// set image in first control
Image1.Source = bitmapImage;
// write to pictures library
var storageFile = await KnownFolders.PicturesLibrary.CreateFileAsync(
fileName,
CreationCollisionOption.ReplaceExisting);
using (var storageStream = await storageFile.OpenAsync(FileAccessMode.ReadWrite))
{
await RandomAccessStream.CopyAndCloseAsync(stream.GetInputStreamAt(0), storageStream.GetOutputStreamAt(0));
}
}
}
// read from pictures library
var pictureFile = await KnownFolders.PicturesLibrary.GetFileAsync(fileName);
using ( var pictureStream = await pictureFile.OpenAsync(FileAccessMode.Read) )
{
bitmapImage.SetSource(pictureStream);
}
Image2.Source = bitmapImage;
}

Create a stream from a bitmap on Windows Runtime

I would like to create a stream from a bitmap. First I did it with :
Stream imgStream = typeof(Main).GetTypeInfo().Assembly.GetManifestResourceStream("ApplicationBlockBase.Assets.testimage.jpg");
But now I need to create a Stream from a local image. Do you have any ideas?
Thanks for your time, regards.

Let me know it this works or not.
StorageFile imageFile = await (await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFolderAsync("Assets")).GetFileAsync("testimage.jpg");
Stream imgStream = await imageFile.OpenStreamForReadAsync();

WinRT Convert Jpg or PNG to GIF

I'm working on a WinRT application that will do some image processing and one of the things I want to do is convert some jpgs or pngs to gif. I have something that sort of works. For some of my test jpgs it works others it's a scrambled image that get's output. Just wondering if there was something I was missing. Here is what I have so far
public async static void ConvertToGif(IRandomAccessStream stream)
{
var decoder = await BitmapDecoder.CreateAsync(stream);
var pixels = await decoder.GetPixelDataAsync();
var file = await KnownFolders.PicturesLibrary.CreateFileAsync("test.gif", CreationCollisionOption.ReplaceExisting);
var outStream = await file.OpenAsync(FileAccessMode.ReadWrite);
var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.GifEncoderId, outStream);
encoder.SetPixelData(decoder.BitmapPixelFormat, BitmapAlphaMode.Ignore,
decoder.PixelWidth, decoder.PixelHeight,
decoder.DpiX, decoder.DpiY,
pixels.DetachPixelData());
await encoder.FlushAsync();
outStream.Dispose();
}
Smaller jpgs seem to work, but larger ones come out scrambled. Is there another way to achieve this?

Duh, the problem was that I was using PixelWidth/Height and I sholud have been using OrientedPixelWidth/Height.
That seems to have resolved my issue for this.