How to add activity indicator to the image in UITa

I have created the Custom tableView and using custom tableView class in Other class to Show the tableView..

I am Loading the image from Server and displaying it in the tableViewRow.. each image is different in it..

On Screen only 7 out of 10 images will come, and when I scroll down the first 3 images are repeating for some time and when those images get load its showing proper images.. but initially till new images will come its showing old images, I want to put a activity indicator to show that the images are loading instead of old images..

I want to add activity Indicator in the place of image, till the image get load..

My code is...

self.tableViewX = tableView;
static NSString *simpleTableIdentifier = @"SimpleTableCell";
SimpleTableCell *cell = (SimpleTableCell *)[tableView1 dequeueReusableCellWithIdentifier:simpleTableIdentifier];
 if (cell == nil)
{
    NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"SimpleTableCell" owner:self options:nil];
    cell = [nib objectAtIndex:0];
}
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^
    {
NSString *imageURL = [NSString stringWithFormat: @"www.xyz.image.png"];
cell.thumbnailImageView.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:imageURL]]];
 });

Please assist me with some sample code..

You can use "AsyncImageView" class files it will load image synchronically and it shows the activity indicator while image loading

You can download "AsyncImageView" class files from following link:- https://www.dropbox.com/s/peazwjvky9fsjd7/Archive.zip

in .m file import AsyncImageView Class

 #import "AsyncImageView.h"

in your tableview cell at indexpath method

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
     static NSString *simpleTableIdentifier = @"SimpleTableCell";
     SimpleTableCell *cell = (SimpleTableCell *)[tableView1 dequeueReusableCellWithIdentifier:simpleTableIdentifier];
     if (cell == nil)
     {
           NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"SimpleTableCell" owner:self options:nil];
      cell = [nib objectAtIndex:0];
     }
     NSString *imageURL = [NSString stringWithFormat: @"www.xyz.image.png"];
     AsyncImageView *async = [[AsyncImageView alloc]initWithFrame:CGRectMake(0, 0, width, height)];
     [async loadImageFromURL:[NSURL URLWithString:imageURL]];
     [cell.thumbnailImageView addSubview:async];
}

try this your problem will solve.