Silverlight 3 Progress Bar when uploading a file
I'm new to Silverlight and I have created a silverlight application to resize and upload images. The problem is the scroll bar doesn't update until the file has finished uploading. I have included sample code of the PushData function and the event handler. Please someone tell me what I'm doing wrong this problem is driving me crazy.
void btnTotalSizes_Click(object sender, RoutedEventArgs e)
{
// ...
UriBuilder ub = new UriBuilder("http://localhost:21636/FileReceiver.ashx");
WebClient wc = new WebClient();
wc.OpenWriteCompleted += (s2, e2) =>
{
PushData(outStream, e2.Result);
e2.Result.Close();
outStream.Close();
};
wc.OpenWriteAsync(ub.Uri);
}
private static void PushData(Stream input, Stream output)
{
byte[] buffer = new byte[4096];
int bytesRead = 0;
int tempTotal = 0;
whi开发者_开发技巧le ((bytesRead = input.Read(buffer, 0, buffer.Length)) != 0)
{
output.Write(buffer, 0, bytesRead);
tempTotal += bytesRead;
_uploadProg++;
int percentDone = (int)(
((decimal)tempTotal / (decimal)input.Length) * 100);
ProgressUpdated(null, new UploadProgressChangedEventArgs(percentDone));
}
}
void MainPage_ProgressUpdated(object sender, UploadProgressChangedEventArgs e)
{
progFileProg.Maximum = 100;
progFileProg.Value = e.ProgressPercentage;
sbUpdateProg.Begin();
}
You need to handle the WebClient.UploadProgressChanged event.
The event handler should update periodically. In the handler, update your UI.
I managed to get it going now. I did to use Dispatcher.BeginInvoke() as was commented by Rubens Farias. Also I had to add the uploading loop into a new thread. I assumed before the async callback would be In a new thread but I guess not.
public static event EventHandler UploadCompleted;
public static event ProgressChangedEvent ProgressUpdated;
public static int _fileLength;
public static int _uploadProg;
private List<FileInfo> _allSelectedFiles = new List<FileInfo>();
public MainPage()
{
InitializeComponent();
Loaded += new RoutedEventHandler(MainPage_Loaded);
btnAnimate.Click += new RoutedEventHandler(btnAnimate_Click);
btnTotalSizes.Click += new RoutedEventHandler(btnTotalSizes_Click);
ProgressUpdated += new ProgressChangedEvent(MainPage_ProgressUpdated);
}
void MainPage_ProgressUpdated(object sender, UploadProgressChangedEventArgs e)
{
Dispatcher.BeginInvoke(() =>
{
progFileProg.Maximum = 100;
progFileProg.Value = _uploadProg;
sbUpdateProg.Begin();
});
}
void MainPage_Loaded(object sender, RoutedEventArgs e)
{
}
void btnTotalSizes_Click(object sender, RoutedEventArgs e)
{
foreach (FileInfo fi in _allSelectedFiles)
{
Stream fileStream = fi.OpenRead();
//DecodedJpeg jpegIn = new JpegDecoder(fileStream).Decode();
//DecodedJpeg jpegOut = new DecodedJpeg(
// new ImageResizer(jpegIn.Image)
// .Resize(1500, ResamplingFilters.NearestNeighbor),
// jpegIn.MetaHeaders); // Retain EXIF details
//MemoryStream outStream = new MemoryStream();
//new JpegEncoder(jpegOut, 90, outStream).Encode();
//outStream.Seek(0, SeekOrigin.Begin);
//outStream.Position = 0;
//UploadFile(fi.Name, outStream, "resources");
UriBuilder ub = new UriBuilder("http://localhost:21636/FileReceiver.ashx");
WebClient wc = new WebClient();
//wc.UploadProgressChanged += (s2, e2) =>
//{
// ProgressUpdated(null, new UploadProgressChangedEventArgs(_uploadProg));
//};
wc.OpenWriteCompleted += (s2, e2) =>
{
System.Threading.Thread thr = new Thread(delegate()
{
PushData(fileStream, e2.Result);
e2.Result.Close();
fileStream.Close();
});
thr.Start();
};
wc.OpenWriteAsync(ub.Uri);
}
}
private static void PushData(Stream input, Stream output)
{
byte[] buffer = new byte[4096];
int bytesRead = 0;
int tempTotal = 0;
while ((bytesRead = input.Read(buffer, 0, buffer.Length)) != 0)
{
output.Write(buffer, 0, bytesRead);
tempTotal += bytesRead;
_uploadProg++;
int percentDone = (int)(((decimal)tempTotal / (decimal)input.Length) * 100);
_uploadProg = percentDone;
ProgressUpdated(null, new UploadProgressChangedEventArgs(percentDone));
Thread.Sleep(50);
}
}
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