Asynchronous image downloading with dispatch_async queue

Hi,

There's no need to implement any framework for LazyImage loading as of now. You can do it simply by writing few lines of code below.. Just take a look..


Example : 

UIActivityIndicatorView *activity = [[UIActivityIndicatorView alloc]init];
UIImageView * userImage = [[UIImageView alloc]init];

        [activity startAnimating];

        dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);

        dispatch_async(queue, ^(void) {

            //  You may want to cache this explicitly instead of reloading every time.

            NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];

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

            dispatch_async(dispatch_get_main_queue(), ^{

                // Capture the indexPath variable, not the cell variable, and use that

               userImage.image = image;

                [activity stopAnimating];

            });

       });

Regards,

Nilesh M. Prajapati

how to share information in iPhone?

Hi,
Recently I have integrated UIActivityViewController in my one of the applications for iOS 6.0 and later versions. For iOS 5.1.1, I used default "twitter.framework".
Please check below code to share information in your application through social media.

//******* Place below code into Implementation part *********//

UIPopoverController *popup;
UIActionSheet *actionSheet;

#define HTML_STR @"" //Any html string which you want to set at the time of sending an email for iOS 5.1.1 and below iOS.

#pragma mark -------------------
#pragma mark Share Button Click event
#pragma mark -------------------

-(IBAction)btnShareClick:(id)sender
{
    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"6.0"))
    {
        [self showActivityView]; // For iOS 6.0 & later ....
    }
    else
    {
        [self showActionSheet]; // For iOS 5.1.1 & below ....
    }
}

#pragma mark -------------------
#pragma mark UIActivityViewController Delegate methods
#pragma mark -------------------

-(void)showActivityView // For iOS 6.0 & later ....
{
    NSMutableDictionary *dictInfo = [array objectAtIndex:index];
   
    //-- set up the data objects
    NSString *Title = [NSString stringWithFormat:@"Promotion Title : %@\n",[dictInfo valueForKey:@"Title"]];
    NSString *fullAddress = [NSString stringWithFormat:@"%@, %@",[dictInfo valueForKey:@"City"],[dictInfo valueForKey:@"StateName"]];
   NSString *validDate = [NSString stringWithFormat:@"Date : %@ To %@ \n",[dictInfo valueForKey:@"strStartDate"],[dictInfo valueForKey:@"strEndDate"]];
    NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"http://www.xyz.com/%@",[dictInfo valueForKey:@"url"]]];
   
    UIImage *image = [UIImage imageNamed:@"title.png"];
    NSArray *activityItems = [NSArray arrayWithObjects:Title,
                              fullAddress,
                              validDate,
                              url,
                              image,nil];
   
    //-- initialising the activity view controller
    UIActivityViewController *activityView = [[UIActivityViewController alloc]initWithActivityItems:activityItems applicationActivities:nil];
    //-- define the activity view completion handler
    activityView.completionHandler = ^(NSString *activityType, BOOL completed)
    {
        NSLog(@"Activity Type selected: %@", activityType);
        if (completed)
        {
            NSLog(@"Selected activity was performed.");
        }
        else
        {
            if (activityType == NULL) {
                NSLog(@"User dismissed the view controller without making a selection.");
            }
            else {
                NSLog(@"Activity was not performed.");
            }
        }
      }
    };
   
    //-- define activity to be excluded (if any)
    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
        activityView.excludedActivityTypes = [NSArray arrayWithObjects:UIActivityTypeAddToReadingList,UIActivityTypeAirDrop,nil];
    }
    else
    {
        activityView.excludedActivityTypes = [NSArray arrayWithObjects:UIActivityTypeSaveToCameraRoll,nil];
    }
   
    if (IS_IPAD)
    {
        if (self.popup) {
            [self.popup dismissPopoverAnimated:NO];
            popup = nil;
        }
        self.popup = [[UIPopoverController alloc] initWithContentViewController:activityView];
        //UIBarButtonItem *barBtn = (UIBarButtonItem *)[self.navigationItem.rightBarButtonItems objectAtIndex:3];
        self.popup.delegate = self;
        [self.popup presentPopoverFromRect:selectedButton.frame inView:selectedButton.superview permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    }
    else
    {
        //-- show the activity view controller
        [self presentViewController:activityView
                           animated:YES completion:^{
                               Appdel.objTab.hidden=YES;
                           }];
    }
}

#pragma mark ------------------------------
#pragma mark UIPopoverController delegate method
#pragma mark ------------------------------

- (void)popoverControllerDidDismissPopover:(UIPopoverController *)popoverController
{
    if (self.popup) {
        [self.popup dismissPopoverAnimated:NO];
        popup = nil;
    }
}
#pragma mark ------------------------------
#pragma mark UIActionSheet delegate method
#pragma mark ------------------------------

-(void)showActionSheet // For iOS 5.1.1 & below
{
    if (actionSheet) {
        [actionSheet dismissWithClickedButtonIndex:3 animated:YES];
        actionSheet = nil;
    }
    actionSheet = [[UIActionSheet alloc]initWithTitle:@"Share with"
                                             delegate:self
                                    cancelButtonTitle:nil
                               destructiveButtonTitle:nil
                                    otherButtonTitles:@"Email",@"Facebook",@"Twitter",@"Cancel",nil];
    if (IS_IPAD)
    {
        [actionSheet showFromRect:selectedButton.frame inView:selectedButton.superview animated:YES];
    }
    else
    {
        [actionSheet showInView:self.view];
    }
}

-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex // For iOS 5.1.1 & below
{
    switch (buttonIndex)
    {
        case 0:
            NSLog(@"Email");
        {
                [self openMailComposer];
        }
            break;
        case 1:
            NSLog(@"Facebook");
        {
            [Appdel.HUD show:YES];
            [self performSelector:@selector(dofacebookLogin) withObject:nil afterDelay:0.5];
        }
            break;
        case 2:
            NSLog(@"Twitter");
        {
                [self sendTwitToYourAccout];
        }
            break;
        case 3:
            NSLog(@"Cancel");
            break;
        default:
            break;
    }
}

- (void)actionSheet:(UIActionSheet *)actionSheet1 didDismissWithButtonIndex:(NSInteger)buttonIndex // For iOS 5.1.1 & below
{
    if (actionSheet) {
        [actionSheet dismissWithClickedButtonIndex:3 animated:YES];
        actionSheet = nil;
    }
}

#pragma mark ------------------------------
#pragma mark MFMailComposeViewController delegate method
#pragma mark ------------------------------


-(void)openMailComposer // For iOS 5.1.1 & below
{
    NSMutableDictionary *dictInfo = [array objectAtIndex:index];
  
    NSString *Title = [NSString stringWithFormat:@"Title : %@</br></br>",[dictInfo valueForKey:@"Title"]];
    NSString *fullAddress = [NSString stringWithFormat:@"%@, %@",[dictInfo valueForKey:@"City"],[dictInfo valueForKey:@"State"]];
    NSString *validDate = [NSString stringWithFormat:@"Date : %@ To %@ </br></br>",[dictInfo valueForKey:@"strStartDate"],[dictInfo valueForKey:@"strEndDate"]];
  
    NSString *strUrl = [NSString stringWithFormat:@"http://www.xyz.com/%@",[dictInfo valueForKey:@"url_name"]];
    NSString *combinedString = [NSString stringWithFormat:@"%@ %@ %@ %@",Title,fullAddress,validDate,strUrl];
    NSString *string = [NSString stringWithFormat:HTML_STR,combinedString,strUrl,[dictInfo valueForKey:@"ImageUrl"]];
  
    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self;
    [picker setSubject:@"Send Mail"];
  
    NSArray *toRecipients = [NSArray arrayWithObject:@""];
    [picker setToRecipients:toRecipients];
  
    NSString *emailBody = [NSString stringWithFormat:@"%@",string];
    [picker setMessageBody:emailBody isHTML:YES];
      
    picker.navigationBar.tintColor=[UIColor colorWithRed:0.976 green:0.612 blue:0.067 alpha:1];
    [self presentModalViewController:picker animated:YES];
    picker = nil;
    toRecipients = nil;
}

- (void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error
{
    [controller dismissModalViewControllerAnimated:NO];
}

#pragma mark ------------------------------
#pragma mark TWTweetComposeViewController delegate method
#pragma mark ------------------------------

-(void)sendTwitToYourAccout// For iOS 5.1.1 & below
{
    if ([TWTweetComposeViewController canSendTweet])
    {
        NSMutableDictionary *dictInfo = [array objectAtIndex:index];
       
        NSString *promotionTitle = [NSString stringWithFormat:@"Title : %@",[dictInfo valueForKey:@"Title"]];
        NSString *validDate = [NSString stringWithFormat:@"Date : %@ To %@",[dictInfo valueForKey:@"strStartDate"],[dictInfo valueForKey:@"strEndDate"]];
        NSString *strUrl = [NSString stringWithFormat:@"http://www.xyz.com/%@",[dictInfo valueForKey:@"url_name"]];
       
        // Initialize Tweet Compose View Controller
        TWTweetComposeViewController *vc = [[TWTweetComposeViewController alloc] init];
        // Settin The Initial Text
        [vc setInitialText:[NSString stringWithFormat:@"%@\n %@",Title,validDate]];
       
        // Adding an Image
        UIImage *image = [UIImage imageNamed:@"title.png"];
        [vc addImage:image];
       
        // Adding a URL
        NSURL *url = [NSURL URLWithString:strUrl];
        [vc addURL:url];
       
        // Setting a Completing Handler
        [vc setCompletionHandler:^(TWTweetComposeViewControllerResult result) {
            [self dismissModalViewControllerAnimated:YES];
        }];
       
        // Display Tweet Compose View Controller Modally
        [self presentViewController:vc animated:YES completion:nil];
    }
    else
    {
        // Show Alert View When The Application Cannot Send Tweets
        NSString *message = @"The application cannot send a tweet at the moment. This is because it cannot reach Twitter or you don't have a Twitter account associated with this device.";
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Warning !" message:message delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];
        [alertView show];
    }
}

#pragma mark ------------------------------
#pragma mark FacebookSDK delegate method
#pragma mark ------------------------------

-(void) dofacebookLogin // For iOS 5.1.1 & below
{
    [SCFacebook loginCallBack:^(BOOL success, id result) {
        if (success) {
            [self sendFeedTofacebook];
        }
        else
        {
            Alert(@"Warning !", result);
        }
    }];
}

- (void)sendFeedTofacebook // For iOS 5.1.1 & below
{
        NSMutableDictionary *dictPromotionInfo = [array objectAtIndex:index];
        NSString *Title = [NSString stringWithFormat:@"Title : %@\n",[dictInfo valueForKey:@"Title"]];
        UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:[dictInfo valueForKey:@"Image"]]]];
      
        NSString *validDate = [NSString stringWithFormat:@"Date : %@ To %@ \n",[dictInfo valueForKey:@"strStartDate"],[dictInfo valueForKey:@"strEndDate"]];

        NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"http://www.xyz.com/%@",[dictInfo valueForKey:@"url_name"]]];
      
        [SCFacebook feedPostWithPhoto:image caption:[NSString stringWithFormat:@"%@ %@ %@ %@",Title,validDate,url] callBack:^(BOOL success, id result)
         {
             if (success) {
                 Alert(@"Info !", @"Your feed has been posted successfully over Facebook.");
             }
             else
             {
                 Alert(@"Warning !", result);
             }
         }];
}


Thanks & Regards,
-----------------------------
Nilesh M. Prajapati