Image Caching not working? - ios

Question

Hello everyone i’m new to ios development , i’m doing JSON parsing and fetch the data and showing on the UITableView with ImageView and Title, Everything works great but image Cacheing is a problem in my code my images are loading but it takes so much time and when i scroll my tableview it again fetch the required image for the cell. Can anybody please come up with caching solution in my present code i already googled many times but unable to figure out this. It really helpful if anyone please suggest me the similar example or assist me on this. Thanks In Advance.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
NSString *post =[[NSString alloc]init];
NSLog(#"PostData: %#",post);
NSURL *url=[NSURL URLWithString:#"http://www.xyz.com/consumer_id=1”];
NSData *postData = [ post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSString *postLength = [NSString stringWithFormat:#"%d", [postData length]];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:url];
[request setHTTPMethod:#"POST"];
[request setValue:postLength forHTTPHeaderField:#"Content-Length"];
[request setValue:#"application/json" forHTTPHeaderField:#"Accept"];
[request setValue:#"application/x-www-form-urlencoded" forHTTPHeaderField:#"Content-Type"];
[request setHTTPBody:postData];
[NSURLRequest setAllowsAnyHTTPSCertificate:YES forHost:[url host]];
NSError *error = [[NSError alloc] init];
NSHTTPURLResponse *response = nil;
NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSLog(#"Response code: %d", [response statusCode]);
if ([response statusCode] >=200 && [response statusCode] <300)
{
NSString *responseData = [[NSString alloc]initWithData:urlData encoding:NSUTF8StringEncoding];
NSLog(#"Response ==> %#", responseData);
SBJsonParser *jsonParser = [SBJsonParser new];
NSDictionary *jsonData = (NSDictionary *) [jsonParser objectWithString:responseData error:nil];
NSLog(#"%#",jsonData);
NSInteger success = [(NSNumber *) [jsonData objectForKey:#"success"] integerValue];
NSLog(#"%d",success);
data = [jsonData objectForKey:#"data"];
}
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [data count];
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 80;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = #"SimpleTableCell";
SimpleTableCell *cell = (SimpleTableCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"SimpleTableCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
NSDictionary *myNames = [data objectAtIndex:[indexPath row]];
NSLog(#"%#",myNames);
[cell.nameLabel setText:[myNames objectForKey:#"name"]];
NSString *imageURL = [myNames objectForKey:#"image"];
NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageURL]];
UIImage *imageIcon = [UIImage imageNamed:#"license.png"];
NSLog(#"ImageIcon %#",imageIcon);
[cell.thumbnailImageView setImage:imageIcon];
cell.thumbnailImageView.image = [UIImage imageWithData:imageData];
return cell;
}

Answer 1

Try to Show the image asynchronously in with setting placeholder image as your images are coming from web service.
dispatch_async(dispatch_get_main_queue(),^{
[image setImageWithURL:your url placeholderImage:[UIImage imageNamed:#""]];
});
Try this SDWebImage from here.

Answer 2

-(void)viewDidAppear:(BOOL)animated
{
NSMutableArray *arrtInvitationList=[[NSMutableArray alloc]init];
NSString * urlString=[NSString stringWithFormat:#"Your Url"];
NSURL *url = [NSURL URLWithString:urlString];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
// NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:urlRequest queue:[NSOperationQueue currentQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
NSError *error1;
NSDictionary *res=[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&error1];
// you are getting dictinary here according ur dictinary parse the data .......
if ([[res valueForKey:#"status"]isEqualToString:#"true"]) {
NSLog(#"%d",[[res valueForKey:#"result"] count]);
for (int i=0; i<[[res valueForKey:#"result"] count]; i++)
{
NSMutableDictionary *dict = [[NSMutableDictionary alloc]init];
//[dict setObject:[[[[res valueForKey:#"player1"] objectAtIndex:i] valueForKey:#"result"] objectAtIndex:i] ];
[arrtInvitationList addObject:dict];
[tblInvite reloadData];
}
[HUD hide:YES];
}else
{
[HUD hide:YES];
}
}];
}
//After that add this array your table view there also when u adding image add asynchronous method
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
//
[NSURLConnection sendAsynchronousRequest:urlRequest queue:[NSOperationQueue currentQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
UIImage *imagemain=[UIImage imageWithData:data];
CGSize size=imagemain.size;
UIImage *compimage=[self resizeImage:imagemain resizeSize:CGSizeMake(45,45)];
//
Cell.imgProfile.image=compimage;
// // CGSize size1=compimage.size;
// }];
this adding image to cell and resize the image also........
-(UIImage *) resizeImage:(UIImage *)orginalImage resizeSize:(CGSize)size
{
CGFloat actualHeight = orginalImage.size.height;
CGFloat actualWidth = orginalImage.size.width;
// if(actualWidth <= size.width && actualHeight<=size.height)
// {
// return orginalImage;
// }
float oldRatio = actualWidth/actualHeight;
float newRatio = size.width/size.height;
if(oldRatio < newRatio)
{
oldRatio = size.height/actualHeight;
actualWidth = oldRatio * actualWidth;
actualHeight = size.height;
}
else
{
oldRatio = size.width/actualWidth;
actualHeight = oldRatio * actualHeight;
actualWidth = size.width;
}
CGRect rect = CGRectMake(0.0,0.0,actualWidth,actualHeight);
UIGraphicsBeginImageContext(rect.size);
[orginalImage drawInRect:rect];
orginalImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return orginalImage;
}