问题
I'm struggling with a easy problem. I want to download an image from web using this code:
WebRequest requestPic = WebRequest.Create(@"http://something.com/" + id + ".jpg");
WebResponse responsePic = await requestPic.GetResponseAsync();
Now I wanted to write the WebResponse's stream in a StorageFile (eg. create a file id.jpg in the app's storage), but I haven't found any way to achieve that. I searched the web for it, but no success - all ways incompatible Stream types and so on.
Could you please help?
回答1:
I have found the following solution, which works and is not too complicated.
public async static Task<StorageFile> SaveAsync(
Uri fileUri,
StorageFolder folder,
string fileName)
{
var file = await folder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
var downloader = new BackgroundDownloader();
var download = downloader.CreateDownload(
fileUri,
file);
var res = await download.StartAsync();
return file;
}
回答2:
You will need to read the response stream into a buffer then write the data to a StorageFile. THe following code shows an example:
var fStream = responsePic.GetResponseStream();
var file = await ApplicationData.Current.LocalFolder.CreateFileAsync("testfile.txt");
using (var ostream = await file.OpenStreamForWriteAsync())
{
int count = 0;
do
{
var buffer = new byte[1024];
count = fStream.Read(buffer, 0, 1024);
await ostream.WriteAsync(buffer, 0, count);
}
while (fStream.CanRead && count > 0);
}
回答3:
That can be done using the C++ REST SDK in Windows Store Apps. It's explained by HTTP Client Tutorial.
来源:https://stackoverflow.com/questions/11363169/winrt-storagefile-write-downloaded-file