show images on tabelview that are come from webservice - iphone

Question

I have used the below code. In this code I am showing images that are coming from the webservices. To increase the scroll speed of tabelview I use UIImageView+WebCache it increase the scrolling speed fast but image is show when I touch the imageview. How to show the images when tabelview is display
NSString *str=[self.uploadimagearry objectAtIndex:indexPath.row];
// NSString *str1=[str stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
NSURL *uploadimageURL = [NSURL URLWithString:[str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
// NSData *imgdata=[NSData dataWithContentsOfURL:uploadimageURL];
//UIImage * uploadimage = [UIImage imageWithData:imgdata];
cell.imageView.frame=CGRectMake(0, -15, 50, 35);
//[cell.imageView setImageWithURL:uploadimageURL];
[cell.imageView setImageWithURL:uploadimageURL];

Answer 1

You have to start NSUrlConnection in a different run-loop, so that you receive data while the table is scrolling.
Just check out below examples :
LazyTableImages
Lazy loading multiple images on background threads on the iPhone

Answer 2

//JImage.h
#import <Foundation/Foundation.h>
#interface JImage : UIImageView {
NSURLConnection *connection;
NSMutableData* data;
UIActivityIndicatorView *ai;
}
-(void)initWithImageAtURL:(NSURL*)url;
#property (nonatomic, retain) NSURLConnection *connection;
#property (nonatomic, retain) NSMutableData* data;
#property (nonatomic, retain) UIActivityIndicatorView *ai;
#end
//JImage.m
#import "JImage.h"
#implementation JImage
#synthesize ai,connection, data;
-(void)initWithImageAtURL:(NSURL*)url {
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
[self setContentMode:UIViewContentModeScaleToFill];
if (!ai){
[self setAi:[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge]];
[ai startAnimating];
[ai setFrame:CGRectMake(27.5, 27.5, 20, 20)];
[ai setColor:[UIColor blackColor]];
[self addSubview:ai];
}
NSURLRequest* request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60];
connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
}
- (void)connection:(NSURLConnection *)theConnection didReceiveData:(NSData *)incrementalData {
if (data==nil) data = [[NSMutableData alloc] initWithCapacity:5000];
[data appendData:incrementalData];
NSNumber *resourceLength = [NSNumber numberWithUnsignedInteger:[data length]];
NSLog(#"resourceData length: %d", [resourceLength intValue]);
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(#"Connection error...");
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[ai removeFromSuperview];
}
- (void)connectionDidFinishLoading:(NSURLConnection*)theConnection
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[self setImage:[UIImage imageWithData: data]];
[ai removeFromSuperview];
}
#end
//Include the definition in your class where you want to use the image
-(UIImageView*)downloadImage:(NSURL*)url:(CGRect)frame {
JImage *photoImage=[[JImage alloc] init];
photoImage.backgroundColor = [UIColor clearColor];
[photoImage setFrame:frame];
[photoImage setContentMode:UIViewContentModeScaleToFill];
[photoImage initWithImageAtURL:url];
return photoImage;
}
//How to call the class
UIImageView *imagV=[self downloadImage:url :rect];
//you can call the downloadImage function in looping statement and subview the returned imageview.
//it will help you in lazy loading of images.
//Hope this will help