NSURLSession를 이용한 방법)
xxx.h
NSURLSession *mealNewsUrlSession;
xxx.m
// initialization
mealNewsUrlSession = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
// use
NSURL *imageURL = [NSURL URLWithString:imagePath];
NSURLRequest *request = [NSURLRequest requestWithURL:imageURL];
NSURLSessionDataTask *task = [mealNewsUrlSession dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
if (error)
{
NSLog(@"ERROR: %@", error);
}
else
{
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
if (httpResponse.statusCode == 200)
{
UIImage *image = [UIImage imageWithData:data];
[mealNewsImageCache setObject:image forKey:imagePath];
dispatch_async(dispatch_get_main_queue(), ^{
[cell.mealPhoto setImage:image];
[cell setNeedsLayout];
//[cell.activityIndicator stopAnimating];
});
}
else
{
NSLog(@"Couldn't load image at URL: %@", imageURL);
NSLog(@"HTTP %ld", (long)httpResponse.statusCode);
}
}
}];
[task resume];
dispatch를 이용한 방법)
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);
dispatch_async(queue, ^(void) {
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:profilePath]];
UIImage* image = [[UIImage alloc] initWithData:imageData];
if (image) {
[mealNewsImageCache setObject:image forKey:profilePath];
dispatch_async(dispatch_get_main_queue(), ^{
[self.profilePhoto setImage:image forState:UIControlStateNormal];
});
}
});
3. 한번에 모두 다운로드 한후에 이용하는 방법)
xxx.h
NSOperationQueue *_asyncQueue;
xxx.m
// initialization
{
_asyncQueue = [[NSOperationQueue alloc] init];
or
_asyncQueue = [NSOperationQueue mainQueue]
or
_asyncQueue = [NSOperationQueue currentQueue]
}
{
// use
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[NSURLConnection sendAsynchronousRequest:request queue:_asyncQueue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
UIImage *image = [[UIImage alloc] initWithData:data];
[Utility saveImageToFS:UIImageJPEGRepresentation(image, 1.0) withUrl:request.URL];
dispatch_async(dispatch_get_main_queue(), ^{
//update cell
});
}];
}); //dispatch_async
}
+ (void) saveImageToFS:(NSData *)data withUrl:(NSURL *)url {
NSString *dir = [[url absoluteString] stringByDeletingLastPathComponent];
NSString *filename = [url.absoluteString lastPathComponent];
//
NSString *path = [NSString stringWithFormat:@"%@/%@",[Utility getMangaRootPath],dir];
if(![[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil])
NSLog(@"fail to create directory ");
NSString *fullpath = [path stringByAppendingFormat:@"/%@",filename];
if(![data writeToFile:fullpath atomically:YES])
NSLog(@"fail to write file");
}
+ (NSString *)getMangaRootPath {
NSString *path = [NSString stringWithFormat:@"%@/%@",
[self getCachesPath],
kMangaEditionDirectory];
// create directory
[[NSFileManager defaultManager] createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil];
return path;
}
+ (NSString*)getCachesPath {
NSString *documentPath = nil;
NSSearchPathDirectory directory;
directory = NSCachesDirectory;
NSArray* directories = NSSearchPathForDirectoriesInDomains(directory, NSUserDomainMask, YES);
if(directories != nil && [directories count] > 0)
documentPath = [directories objectAtIndex:0];
return documentPath;
}
