我想使用 NSURLconnection 一个一个地下载多个文件,一个可以做的最大下载是 5。这个过程就像启动第一次下载,当第一次下载完成时才开始第二次下载,当第二次完成时开始第三次下载.同样适用于第四次下载和第五次下载。我能够下载一个文件。相同的代码是:
- (IBAction)download1:(id)sender {
_fileName = @"dog-wallpaper-dogs.jpg";
_currentURL = [NSString stringWithFormat:@"http://noruffdaysdotcom1.files.wordpress.com/2012/04/%@",_fileName];
NSLog(@"currenturl%@",_currentURL);
NSLog(@"the filename is %@",_fileName);
NSURL *url =[NSURL URLWithString:_currentURL];
NSURLRequest *theRequest = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:60];
_receivedData = [[NSMutableData alloc]initWithLength:0];
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:theRequest delegate:self startImmediately:YES];
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
NSLog(@"THE STATUS CODE IS %d",[httpResponse statusCode]);
statuscode = [httpResponse statusCode];
NSLog(@"into didReceiveResponse");
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
[_receivedData setLength:0];
expectedBytes = [response expectedContentLength];
NSLog(@"EXPECTED BYTES:%ld",expectedBytes);
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// NSLog(@"into did receivedata");
[_receivedData appendData:data];
// float progressive = (float)[_receivedData length] / (float)expectedBytes;
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
flag= 0;
NSLog(@"into didfailwitherror");
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
NSLog(@"connection failed");
}
-(NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse
{
return nil;
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{ flag = 0;
NSLog(@"into didfinishloading");
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSLog(@"DOCUMENT DIRECTORY :%@",documentsDirectory);
// [NSFileManager isWritbleAtPath:documentsDirectory];
// [NSFileManager isWritableAtPath:documentsDirectory];
_imagePath = [documentsDirectory stringByAppendingPathComponent:_fileName];
NSLog(@"iamge path:%@",_imagePath);
NSLog(@"succeeded");
[UIApplication sharedApplication].networkActivityIndicatorVisible= NO;
NSLog(@"Succeeded! Received %d bytes of data",[_receivedData length]);
// flag= [_receivedData writeToFile:imagePath atomically:NO];
if([_receivedData writeToFile:_imagePath atomically:YES])
{
flag= 1;
NSLog(@"write successfull");
}
else{
flag =0;
NSLog(@"write failed");
}
UIImage *img =[UIImage imageWithContentsOfFile:_imagePath];
self.imageview.image = img;
isloaded = YES;
}
请帮助我如何在之前完成后进行下一次下载。