CODEWITHSUNDEEP
iphoneprogress-barnsurlconnection
dontWatchMyProfile
dontWatchMyProfile

Reputation: 46310

How to make an progress bar for an NSURLConnection when downloading a file?

I want to show up an progress bar while a download with NSURLConnection is happening. As I am getting data from the server, I could update the UI for every received package. But the problem is: How do I figure out how much data I have already, and how much data has to be downloaded? Probably in bytes... And then I have to do some math to get the percentage?

Upvotes: 24

Views: 23723

Answers (1)

Stefan Arentz
Stefan Arentz

Reputation: 34935

In your NSURLConnection delegate, implement something like this to find out the total content length. The server has to support this, but it will most likely work fine with static content:

- (void)connection: (NSURLConnection*) connection didReceiveResponse: (NSHTTPURLResponse*) response
{
    statusCode_ = [response statusCode];
    if (statusCode_ == 200) {
        download_.size = [response expectedContentLength];
    }
}

And then update progress like this:

- (void) connection: (NSURLConnection*) connection didReceiveData: (NSData*) data
{
    [data_ appendData: data];
    download_.progress = ((float) [data_ length] / (float) download_.size);
    // Broadcast a notification with the progress change, or call a delegate
}

In my case I have a download instance that has size and progress properties. They are owned by a global DownloadManager object that will take care of notifying interested parties of the download progress or state changes.

Upvotes: 64

Related Questions