In this tutorial, we’ll learn How to download files with C# from a web server
Microsoft .Net framework provides a set of classes that manage Internet communications and one in particular can be used to download files with C# from the internet to the local hard drive. This can be used to download a data set, for example, or to download program updates.
There are two methods for downloading a file, synchronously and asynchronously.
Synchronous Download
A Synchronous download will only allow one download to be processed, and while it is being processed, the main program thread will pause until the download is complete. It is the simplist method to implement, and if you can wait for the download to complete, it is often the best method to use.
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using System.Net; WebClient webClient = new WebClient(); webClient.DownloadFile("http://mysite.com/myfile.txt", @"c:\myfile.txt"); |
Asynchronous Download
To download file without blocking the main thread use asynchronous method DownloadFileAsync. You can also set event handlers to show progress and to detect that the file is downloaded.
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private void btnDownload_Click(object sender, EventArgs e) { WebClient webClient = new WebClient(); webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed); webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged); webClient.DownloadFileAsync(new Uri("http://mysite.com/myfile.txt"), @"c:\myfile.txt"); } private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e) { progressBar.Value = e.ProgressPercentage; } private void Completed(object sender, AsyncCompletedEventArgs e) { MessageBox.Show("Download completed!"); } |
