How can download audio? objective-c - ios

Question

I have audio player. I download audio in this way
- (void) song{
if (_index == 0) {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"1.mp3"];
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:filePath isDirectory:NO];
if (!fileExists) {
NSString *stringURL = #"https://drive.google.com/uc?export=download&id=0B6zMam2kAK39VHZ1cUZsM3BhQXM";
NSURL *url = [NSURL URLWithString:stringURL];
NSData *urlData = [NSData dataWithContentsOfURL:url];
[urlData writeToFile:filePath atomically:YES];
}
self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL URLWithString:filePath] error:nil];
}
}
But when audio downloading I can’t do anything. User interface stop.
How can download audio and do anything in user interface simultaneously?

Answer 1

Give your method a block to execute when finished, then run the download code in the background. Lets say, for your case the output is a local file with the downloaded content:
- (void)songWithCompletion:(void (^)(NSString *))completion {
NSString *filePath = [self song];
dispatch_async(dispatch_get_main_queue(), ^{
if (completion) completion(filePath);
});
}
Change the song method to return filePath. Don't ever call it directly, only via songWithCompletion.
- (void)song {
// ... your code from the OP
// don't allocate the audio player here, just return the local file
return filePath;
}
Call it like this...
[self songWithCompletion:^(NSString *filePath) {
if (filePath) {
self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL URLWithString:filePath] error:nil];
// you should really handle audio player error here, too
} else {
// handle error
}
}];

Answer 2

You are downloading the file in the main thread. you need to make an asynchronous call in order to avoid stopping UI.

Answer 3

-(void)downloadAudio
{
NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:#"https://drive.google.com/uc?export=download&id=0B6zMam2kAK39VHZ1cUZsM3BhQXM"]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if (theConnection) {
receivedData = [NSMutableData data] ;
} else {NSLog(#"no connection!");
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
NSLog(#"Succeed! Received %d bytes of data",[receivedData length]);
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
//NSLog(#"%#", [documentPaths objectAtIndex:0]);
NSString *documentDirectoryPath = [documentPaths objectAtIndex:0];
NSString *folderPath = [documentDirectoryPath stringByAppendingPathComponent:#"audioFile.mp3"];
[receivedData writeToFile:folderPath atomically:YES];
NSURL *soundURL = [NSURL fileURLWithPath:folderPath];
NSError *error;
if ([[NSFileManager defaultManager] fileExistsAtPath:folderPath]) {
player = [[AVAudioPlayer alloc]initWithContentsOfURL:soundURL error:&error];
player.volume=0.5;
NSError *error = nil;
if (!error) {
[player play];
NSLog(#"File is playing!");
}
else{
NSLog(#"Error in creating audio player:%#",[error description]);
}
}
else{
NSLog(#"File doesn't exist");
}
}