Calculation of the percentage of progress

Question

I am using webclient for dowlnoad file. I calculate the percentage of progress as below

• I know the size of the file (I read it from the database table) of the file that will be downloaded.

• I rely on the BytesRecieved WebClient property to know all the bytes received at boot time.

• Algorithm used by me double dProgress = (e.BytesReceived / FileSize)*100); to calculate the percentage of progress.

However, I am not getting the right percentage of progress to update the progress bar.

Is there any method for calculating the percentage of progress?

Answer 1

Look at the following line: double dProgress = (e.BytesReceived / FileSize)*100)

If both e.BytesReceived and FileSize are integers, you will always have 0 * 100 = 0 .

Do something like this:

double dProgress = ((double)e.BytesReceived / FileSize)*100.0

This is because / performs integer division when dividing two integers. But you don’t want it. Therefore, you convert one of the variables to double .

Answer 2

If you handle the DownloadProgressChanged event while performing asynchronous loading, the args events already have ProgressPercentage , so there is no point in reinventing it. A contrived example:

 var client = new WebClient(); var reset = new ManualResetEvent(false); client.DownloadProgressChanged += (s, e) => Console.WriteLine("{0} percent complete", e.ProgressPercentage); client.DownloadFileCompleted += (s, e) => reset.Set(); client.DownloadFileAsync(new Uri("http://myfilepathhere.com"), "file.name"); //Block till download completes reset.WaitOne(); 

Answer 3

BytesReceived and FileSize are most likely integers, so you need to calculate the progress like this:

 double dProgress = 100.0 * e.BytesReceived / FileSize; 

Answer 4

The problem is that both numbers are integers. When you separate them, they become less than 1, so they are rounded to 0. Typecast them to make the result float:

 double dProgress = ((double)e.BytesReceived / FileSize)*100) 

Answer 5

This is a very difficult problem with basic arithmetic and C # casting.

Decision

First save the result of integer division in a double variable. And then enter cast for the integer.

 int x = 5, y = 10, answer; double ansDouble; answer = (int)(x / y) * 100; //percentage calculation Console.WriteLine("percentage={0}", answer); //>output percentage=0 answer = (int)((double)x / y) * 100; //percentage calculation Console.WriteLine("percentage={0}", answer); //>output percentage=0 answer = (int)((double)x / (double)y) * 100; //percentage calculation Console.WriteLine("x={0}", answer); //>output percentage=0 answer = (int)(x/(double)y) * 100; //percentage calculation Console.WriteLine("x={0}", answer); //>output percentage=0 ansDouble = ((double)x / y) * 100; answer = (int)ansDouble; Console.WriteLine("percentage={0}", answer); //>output percentage=50 

Notes for notes

It turns out that x / y = 0, for any values ​​of x and y, if they are integers. We cannot solve this in one line using any combination of casting

Answer 6

Try the following:

 WebClient Client = new WebClient(); Client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged); 

...

  void ProgressChanged(object sender, DownloadProgressChangedEventArgs e) { double bytesIn = double.Parse(e.BytesReceived.ToString()); double totalBytes = double.Parse(e.TotalBytesToReceive.ToString()); double percentage = bytesIn / totalBytes * 100; int percente = int.Parse(Math.Truncate(percentage).ToString()); progressBar.Value = percente; } 

Or just using the value of ProgressPercentage .

  void ProgressChanged(object sender, DownloadProgressChangedEventArgs e) { progressBar.Value = e.ProgressPercentage; }