Synchronously download an image from URL
I just want to get a BitmapImage from a internet URL, but my function doesn't seem to work properly, it only return me a small part of the image. I know WebResponse is working async and that's certainly why I have this problem, but how can I do it synchronously?
internal static BitmapImage GetImageFromUrl(string url)
{
Uri urlUri = new Uri(url);
WebRequest webRequest = WebRequest.CreateDefault(urlUri);
webRequest.ContentType = "image/jpeg";
WebResponse webResponse = webRequest.GetResponse();
BitmapImage image = new BitmapImage();
image.BeginInit();
image.StreamSource = webResponse.GetResponseStream();
image.EndInit();
开发者_StackOverflow社区 return image;
}
First you should just download the image, and store it locally in a temporary file or in a MemoryStream
. And then create the BitmapImage
object from it.
You can download the image for example like this:
Uri urlUri = new Uri(url);
var request = WebRequest.CreateDefault(urlUri);
byte[] buffer = new byte[4096];
using (var target = new FileStream(targetFileName, FileMode.Create, FileAccess.Write))
{
using (var response = request.GetResponse())
{
using (var stream = response.GetResponseStream())
{
int read;
while ((read = stream.Read(buffer, 0, buffer.Length)) > 0)
{
target.Write(buffer, 0, read);
}
}
}
}
Why not use System.Net.WebClient.DownloadFile
?
string url = @"http://www.google.ru/images/srpr/logo3w.png";
string file = System.IO.Path.GetFileName(url);
System.Net.WebClient cln = new System.Net.WebClient();
cln.DownloadFile(url,file);
this is the code i use to grab an image from a url....
// get a stream of the image from the webclient
using ( Stream stream = webClient.OpenRead( imgeUri ) )
{
// make a new bmp using the stream
using ( Bitmap bitmap = new Bitmap( stream ) )
{
//flush and close the stream
stream.Flush( );
stream.Close( );
// write the bmp out to disk
bitmap.Save( saveto );
}
}
The simpliest is
Uri pictureUri = new Uri(pictureUrl);
BitmapImage image = new BitmapImage(pictureUri);
you can then change BitmapCacheOption to start the retrieval process. However, image is retrieved in async. But you shouldn't care much
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