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Iphone app: -My app crash

I am making one custom cell class as follows.

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {

self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {

    /*imgview=[[UIImageView alloc]initWithFrame:CGRectMake(10, 15, 40, 20)];
    imgview.backgroundColor = [UIColor clearColor];
    imgview.opaque = NO;*/

    Name = [[UILabel alloc]initWithFrame:CGRectMake(75, 10, 130, 30)];
    Name.backgroundColor = [UIColor clearColor];
    Name.textColor=[UIColor blueColor];
    Name.font=[UIFont fontWithName:@"Arial" size:16.0];
    Name.textAlignment=NSTextAlignmentLeft;

    CGSize textSize = [[Name text] sizeWithFont:[Name font]];
    CGFloat strikeWidth = textSize.width;
    ScreenName =[[UILabel alloc]initWithFrame:CGRectMake(strikeWidth+75.0, 25  , 150, 40)];
    ScreenName.backgroundColor = [UIColor clearColor];
    ScreenName.textColor=[UIColor redColor];
    ScreenName.font=[UIFont fontWithName:@"Arial" size:16.0];
    ScreenName.textAlignment=NSTextAlignmentLeft;

    tweetview=[[UITextView alloc]initWithFrame:CGRectMake(75, 50, 200, 70)];
    tweetview.backgroundColor = [UIColor clearColor];
    tweetview.textColor=[UIColor redColor];
    tweetview.font=[UIFont fontWithName:@"Arial" size:16.0];        
    tweetview.textAlignment=NSTextAlignmentLeft;
    tweetview.editable=NO;
    tweetview.dataDetectorTypes=UIDataDetectorTypeLink;

    Minutes=[[UILabel alloc]initWithFrame:CGRectMake(270, 20, 150, 50)];
    Minutes.backgroundColor = [UIColor clearColor];
    Minutes.textColor=[UIColor blueColor];
    Minutes.font=[UIFont fontWithName:@"Arial" size:14.0];
    Minutes.textAlignment=NSTextAlignmentLeft;

    //  [self.contentView addSubview:imgview];
    [self.contentView addSubview:Name];
    [self.contentView addSubview:ScreenName];
    [self.contentView addSubview:Minutes];

    //  [self.contentView addSubview:LastTweet];
    [self.contentView addSubview:tweetview];

}

return self;
}

and use it in the nextviewcontroller.minstance method tableView:didSelectRowAtIndexPath:as follows:

CustomCell *cell = (CustomCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
   // cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]autorelease];
        cell = [[[CustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]autorelease];

}

my application fails every time with a message

Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...
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2 answers

This is because you are making some user interface changes in the background thread. In ios, you cannot make any user interface changes in the background thread, this will cause your application to crash.

So you have to make changes to the user interface in the main thread

[self performSelectorOnMainThread:@selector(doYourUIChanges:) withObject:nil waitUntilDone:YES];

Or

dispatch_async(dispatch_get_main_queue(), ^{ 
//Your Task
});

or

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    // background code
});
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As pointed out by @ Rajneesh071, user interface changes must be made in the main thread.

, :

[self performSelectorOnMainThread:@selector(doYourUIChanges:) withObject:nil waitUntilDone:YES];

, , , :

dispatch_async(dispatch_get_main_queue(), ^{
    /* YOUR UI STUFF */
});
+1

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