Download image through AFNetworking & edit it - ios

Question

I'm trying to download some image files from a remote server through the AFNetworking (UIImageView+AFNetworking.h) & retrieve the UIImage from it, edit that image. Editing means add that image(downloaded image) on top of another png file.( background image - UIImage )
I have tried several code blocks finally I'm stuck in here . I'm getting a black box only. Can't see the actual server image .
-(UIImage *)downloadImages:(NSString *)url{
UIImageView *downloadedImageView = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,40,40)];
[downloadedImageView setImageWithURL:[NSURL URLWithString:url]
placeholderImage:[UIImage imageNamed:#"Loading_image"]];
UIGraphicsBeginImageContextWithOptions(downloadedImageView.bounds.size, downloadedImageView.opaque, 0.0);
[downloadedImageView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
Then I'm calling through that function in a for loop.
for( int i=0;i<[Images count];i++){
NSString *image_Url = [NSString stringWithFormat:#"%#%#",imageURL, imagename];
UIImage *downloadimage =[[UIImage alloc]init];
downloadimage = [self downloadImages:image_Url];
UIImage *bottomImage = [UIImage imageNamed:#"map_marker_black"];
CGSize newSize = CGSizeMake(60, 60);
UIGraphicsBeginImageContext( newSize );
[backgroundImage drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
[downloadimage drawInRect:CGRectMake(0,0,newSize.width,newSize.height) blendMode:kCGBlendModeNormal alpha:0.7];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
Where am I doing wrong ? Your help is highly appreciated. Thanks a lot

Answer 1

A few issues. Lets start with the download code. There is no reason to deal with an image view and drawing it to create an image. Just use the actual image:
- (UIImage *)downloadImage:(NSString *)url{
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
UIImage *image = [UIImage imageWithData:imageData];
return image;
}
The big issue with your original code is that the AFNetworking method you used runs in the background. So you were always trying to draw the "loading" image.
Now the drawing code:
// Only need to load this once
UIImage *backgroundImage = [UIImage imageNamed:#"map_marker_black"];
// What is the loop used for?
for (NSUInteger i = 0; i < [Images count]; i++){
// Where does imageURL and imagename come from?
NSString *imageURL = [NSString stringWithFormat:#"%#%#",imageURL, imagename];
UIImage *downloadImage = [self downloadImage:imageURL];
CGRect newRect = CGRectMake(0, 0, 60, 60);
UIGraphicsBeginImageContextWithOptions(newRect.size, NO, 0.0);
[backgroundImage drawInRect:newRect];
[downloadimage drawInRect:newRect blendMode:kCGBlendModeNormal alpha:0.7];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
// Do something here with newImage
UIGraphicsEndImageContext();
}
Note the comments in the code.