unable to scroll table in iOS - ios

Question

I'm load an array of dictionary in a table view and after reload my table I called a method which change the data of dictionary from array and then refresh/reload particular index of tableview. But I'm not able to scroll my table until unless my complete data not updated again.
Code from where I call my method and reload table:
- (void)parserDidEndDocument:(NSXMLParser *)parser {
[Hud hideAnimated:true];
[self.myTbl reloadData];
dispatch_async(dispatch_get_main_queue(),^{
[self loadTutorials];
});
}
method in which I'm trying to update my table data.
#pragma mark:GetAllData
-(void)loadTutorials{
dispatch_async(dispatch_get_main_queue(),^{
int k = 0;
for (NSMutableString*linknew in linkArr) {
//here some calculations code for parsing then next
for (TFHppleElement *elements in contributorsNodes) {
// 5
for (TFHppleElement *child in elements.children) {
if ([child.tagName isEqualToString:#"img"]) {
// 7
#try {
NSString*url = [child.attributes objectForKey:#"src"];
NSMutableDictionary*dict = [[feeds objectAtIndex:k] mutableCopy];
[dict setObject:url forKey:#"image"];
[feeds removeObjectAtIndex:k];
[feeds insertObject:dict atIndex:k];
NSIndexPath*index = [NSIndexPath indexPathForRow:k inSection:0];
[self.myTbl reloadRowsAtIndexPaths:#[index] withRowAnimation:UITableViewRowAnimationNone];
}
#catch (NSException *e) {}
}
}
}k++;
}
});
}
cellForRowAtIndexPath method:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell" forIndexPath:indexPath];
UILabel*lbl = (UILabel*)[cell viewWithTag:101];
UIImageView*imgView = (UIImageView*)[cell viewWithTag:103];
[imgView sd_setImageWithURL:[NSURL URLWithString:[[feeds objectAtIndex:indexPath.row] objectForKey:#"image"]] placeholderImage:[UIImage imageNamed:#"img.jpg"]];
lbl.text = [NSString stringWithFormat:#"%#",[[feeds objectAtIndex:indexPath.row] objectForKey: #"title"]];
return cell;
}

Answer 1

Have many things in your question make me confused.
With parserDidEndDocument method, I don't know why you need to call [self.myTbl reloadData] although after that you update self.myTbl inside loadTutorials method.
Why do you need to call 2 dispatch_async here, both outside and inside loadTutorials method? I think it's not necessary. Just call 1 time.
To replace an object in an array, you don't need to remove and insert object. Just replace by using feeds[k] = dict. Make sure feeds.count > k before using.
As i guess, you use try catch because you got crash when updating self.myTbl inside loadTutorials method. In my opinion, you should use beginUpdates and endUpdates instead of try catch.
I think the problem is because you used try catch to handle crash.
Try to rewrite you code with background queue as #Losiowaty suggested, we will have
- (void)parserDidEndDocument:(NSXMLParser *)parser {
[Hud hideAnimated:true];
[self.myTbl reloadData];
[self loadTutorials];
}
#pragma mark:GetAllData
-(void)loadTutorials{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
int k = 0;
for (NSMutableString*linknew in linkArr) {
//here some calculations code for parsing then next
for (TFHppleElement *elements in contributorsNodes) {
// 5
for (TFHppleElement *child in elements.children) {
if ([child.tagName isEqualToString:#"img"]) {
NSString*url = [child.attributes objectForKey:#"src"];
// I assume in some case, feeds[k] doesn't exist. We need add an
// NSMutableDictionary to this index before using to avoid crash.
// If you make sure feeds[k] always exist you can ignore it
if (feeds.count == k) {
[feeds addObject:[[NSMutableDictionary alloc] init]];
}
[feeds[k] setObject:url forKey:#"image"];
NSIndexPath*index = [NSIndexPath indexPathForRow:k inSection:0];
dispatch_async(dispatch_get_main_queue(), ^{
[self.myTbl beginUpdates];
[self.myTbl reloadRowsAtIndexPaths:#[index] withRowAnimation:UITableViewRowAnimationNone];
[self.myTbl endUpdates];
});
}
}
}k++;
}
});
}
Let try the code first. If you still have any problem, let me know. I will help you.