このサイトでNSURLに関するほとんどすべての投稿を見てきましたが、まだ行き詰まっています。Xcode4.5を使用しています。
画像をダウンロードしてUIScrollViewに表示しようとしています。
JSONを使用して入力された配列に格納されるURLを使用して、非同期でダウンロードする画像をダウンロードしたいと思います。データベースからJSONグラブからURLを取得します。これは非常にうまく機能し、URLがurlArrayに配置されていることを確認できますが、画像を取得するためにURLConnectionを作成すると失敗するようです。
ダウンロードする画像を取得できないか、少なくともimageArrayに表示されません。
これが私のコードです。助けてくれてありがとう！他に何が必要か教えてください
- (void)viewDidLoad
{
[super viewDidLoad];
//show network activity to user.... very useful
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
//call getJSON. getJSON does not parse, but it connects and gets the data.
[self getJSON];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)getJSON
{
NSURL *url = [NSURL URLWithString:@"http://"My server goes here/json.php"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
//just initialize the connection, do not
[[NSURLConnection alloc] initWithRequest:request delegate:self]; //"Ecression result unused" warning here
}
- (void)getNextImage
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
for (int y = 0; y < urlArray.count; y++)
{
NSString *urlString = [urlArray objectAtIndex:y];
NSLog(@"Array String is: %@ ", urlString);
NSURL *arrayURL = [NSURL URLWithString:urlString];
NSURLRequest *imageRequest = [NSURLRequest requestWithURL:arrayURL];
NSData *imgData = [[NSURLConnection alloc] initWithRequest:imageRequest delegate:self]; //"Incompatible pointer types initializing ..." warning here
imageData = [UIImage imageWithData:imgData];
[imageArray addObject:imageData];
}
NSLog(@"LEAVING getNextImage");
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
theJsonData = [[NSMutableData alloc] init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[theJsonData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
urlArray = [[NSMutableArray alloc] init];
//This is where all the JSON Parsing is being done.
//Turn off the data indicator, because the download is complete.
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
jsonArray = [NSJSONSerialization JSONObjectWithData:theJsonData options:nil error:nil]; //"Incompatible pointer types initializing ..." warning here
//get the URL strings out of the jsonArray
for (int x = 0; x < jsonArray.count; x++)
{
NSString *urlString = [[jsonArray objectAtIndex:x] objectForKey:@"image_URL"];
NSLog(@"String is %@ ", urlString);
[urlArray addObject:urlString];
}
[self getNextImage];
//display the images..... Not sure why this is in connectionDidFinishLoading.
for (int x = 0; x < imageArray.count; x++)
{
CGRect frame;
frame.origin.x = self.mainScroll.frame.size.width * x;
frame.origin.y = 0;
frame.size = self.mainScroll.frame.size;
UIImageView *nextIV = [[UIImageView alloc] initWithFrame:frame];
[nextIV setImage:imageData];
[self.mainScroll addSubview:nextIV];
//NSLog(@"Pass %d", x);
}
self.mainScroll.contentSize = CGSizeMake(self.mainScroll.frame.size.width * imageArray.count,1.0);
NSLog(@"!!!!!!leaving connection did finnish loading!!!!!");
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
//show error message to user if there is a connection error.
UIAlertView *errorView = [[UIAlertView alloc] initWithTitle:@"Error" message:@"The Download could not complete - please make sure you're connected to the internet." delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];
[errorView show];
//turn off the network activity indicatior
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}