File downloading in a BackgroundWorker

Pieter De Decker

Currently, I can do

string strXMLfile = FileDownload("http://link/to/some/xml/file");

to download the contents of a file into a string. Is there a way to execute the file download in a BackgroundWorker and still have the method FileDownload return the contents of the requested file?

3 Replies

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tim dinh17y ago
Accepted answer
Something like below?

Func fileDownload = new Func(FileDownload);
fileDownload.BeginInvoke("url",new AsyncCallback(FileDownloadCallback),fileDownload);

private void FileDownloadCallback(IAsyncResult result)
{
Func fileDownload = result.AsyncState as Func;
string fileContent = fileDownload.EndInvoke(result);
}
Pieter De Decker17y ago
Both of you made good suggestions that I will certainly keep in mind for other programs. For this particular program, I decided to put the method containing the call to FileDownload in a BackgroundWorker, since my program would still lag too much if I only put the file downloading code in a BackgroundWorker.
Ashley Argile17y ago
I'm not sure if this is what you wanted...

Add a backgroundWorker and handle the following events..

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            file = FileDownload((string)e.Argument);
        }

        private void backgroundWorker1_RunWorkerCompleted(object sender,                             RunWorkerCompletedEventArgs e)
        {
                MessageBox.Show(file);
        }

start the download with - backgroundWorker1.RunWorkerAsync("http://link/to/some/xml/file");

Store the output of FileDownload in a local variable and retrieve it when the RunWorkerCompleted event fires.

Hope this helps..

regards

Ashley