The problem with the table view of the iOS table, I use sending and saving the cache

Question

    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {

        TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"TableViewCell" forIndexPath:indexPath];

        cell.tag = indexPath.row;
        //cell.imageView.image = nil;

        // Rounded Rect for cell image
        CALayer *cellImageLayer = cell.imageView.layer;
        [cellImageLayer setCornerRadius:25];
        [cellImageLayer setMasksToBounds:YES];



        [self getImages];
        [self storeImages];
        UIImage *image =_ResimSonHali[indexPath.row];
        dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);

        dispatch_async(queue, ^(void) {



            if (image) {

                dispatch_async(dispatch_get_main_queue(), ^{
                    if (cell.tag == indexPath.row) {

                        CGSize itemSize = CGSizeMake(50, 50);
                        UIGraphicsBeginImageContext(itemSize);
                        CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
                        [image drawInRect:imageRect];


                       // cell.ThumbImage.image = image1;
                        cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();

                        UIGraphicsEndImageContext();
                        [cell setNeedsLayout];

                    }
                });
            }
        });

        cell.TitleLabel.text = _TarifAdi[indexPath.row];
        return cell;

    }

-(void)getImages
{

    NSMutableArray *fuckingArrayYemek = [[NSMutableArray alloc] init];

    for (int i=0; i<[_ResimAdiBase count]; i++)
    {
        NSString *testString=_ResimAdiBase[i];
        NSArray *ImageNames = [testString componentsSeparatedByString:@"."];
        [self cacheImage: _ResimAdi[i] : ImageNames[0] ];
        [fuckingArrayYemek addObject:ImageNames[0]];


    }

    _ResimSonAdi = fuckingArrayYemek;

}

-(void) storeImages
{
     NSMutableArray *fuckingArrayYemekName = [[NSMutableArray alloc] init];
    for (int i=0; i<[_ResimAdiBase count]; i++)
    {
        [fuckingArrayYemekName addObject:[self getCachedImage:_ResimSonAdi[i]]];

    }
    _ResimSonHali = fuckingArrayYemekName;


}
- (void) cacheImage: (NSString *) ImageURLString : (NSString *)imageName
{
    NSURL *ImageURL = [NSURL URLWithString: ImageURLString];

    // Generate a unique path to a resource representing the image you want

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *docDir = [paths objectAtIndex: 0];
    NSString *docFile = [docDir stringByAppendingPathComponent: imageName];

    // Check for file existence
    if(![[NSFileManager defaultManager] fileExistsAtPath: docFile])
    {
        // The file doesn't exist, we should get a copy of it

        // Fetch image
        NSData *data = [[NSData alloc] initWithContentsOfURL: ImageURL];

        UIImage *image = [[UIImage alloc] initWithData: data];

        // Is it PNG or JPG/JPEG?
        // Running the image representation function writes the data from the image to a file
        if([ImageURLString rangeOfString: @".png" options: NSCaseInsensitiveSearch].location != NSNotFound)
        {

            [UIImagePNGRepresentation(image) writeToFile: docFile atomically: YES];

        }
        else if([ImageURLString rangeOfString: @".jpg" options: NSCaseInsensitiveSearch].location != NSNotFound ||
                [ImageURLString rangeOfString: @".jpeg" options: NSCaseInsensitiveSearch].location != NSNotFound)
        {
            [UIImageJPEGRepresentation(image, 100) writeToFile: docFile atomically: YES];
        }
    }
}


- (UIImage *) getCachedImage : (NSString *)imageName
{

    NSArray *paths = NSSearchPathForDirectoriesInDomains
    (NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString* cachedPath = [documentsDirectory stringByAppendingPathComponent:imageName];

    UIImage *image;

    // Check for a cached version
    if([[NSFileManager defaultManager] fileExistsAtPath: cachedPath])
    {
        image = [UIImage imageWithContentsOfFile: cachedPath]; // this is the cached image
    }
    else
    {
        NSLog(@"Error getting image %@", imageName);
    }

    return image;
}

When I load 20 data, our table does not lag behind, but when we try to increase the representation of the table of data sizes, we get a backlog from how we can prove this problem. At first we tried sending, then we tried to save the image cache, but we have a lag. Approximately we deal with this problem for about 3 days.

Answer 1

This is a problem in the cacheImage () method that is called every time the cellForRowAtIndexPath method is called.

NSData *data = [[NSData alloc] initWithContentsOfURL: ImageURL];

So, to solve the problem, use this line in the dispatch_async section. And update your code to match it.