How to Animate uilabel text between 3 values

Question

What I want is to animate my UILabel's text between 3 values repeatedly. The text I'd like to set is 'downloading.', 'downloading..', 'downloading...', and then, repeat. With this animation, I want to let my user know that the downloading is being done and the app is not stacked. I've been searching with google for a while and did not find a solution.

Any one can give me some reference about this? Thanks in advance.

Answer 1

Use the NStimer for changing the text

in .h file

@interface ViewController : UIViewController
{
    NSTimer * timer;
    UILabel * downloadingLbl;
}

and in .m file

- (void)viewDidLoad
{
    [super viewDidLoad];

    downloadingLbl.text = @"Downloading.";
    if (!timer) {
        timer = [NSTimer timerWithTimeInterval:0.5 target:self selector:@selector(onTick:) userInfo:nil repeats:YES];
    }
}

-(void)onTick:(NSTimer*)timer
{
    NSLog(@"Tick...");

    if ([downloadingLbl.text isEqualToString:@"Downloading."]) {
        downloadingLbl.text = @"Downloading..";
    } else if ([downloadingLbl.text isEqualToString:@"Downloading.."]) {
        downloadingLbl.text = @"Downloading...";
    } else if ([downloadingLbl.text isEqualToString:@"Downloading..."]) {
        downloadingLbl.text = @"Downloading.";
    }
}

And when your download complete that make timer invalidate.

[timer invalidate];

Answer 2

for that you have to schedule the timer like this:

int count = 1;
NSTimer *myTimer = [NSTimer scheduledTimerWithTimeInterval:1
                       target:self 
                       selector:@selector(updateLabel) 
                       userInfo:nil 
                       repeats:YES];

Now below method will get called in every (in seconds) periods

- (void) updateLabel {
    if(count == 1)
    {
    label.text = @"Downloading."

    count = 2;
    }
    else if(count == 2)
    {
    label.text = @"Downloading.."

    count = 3;
    }
    else if(count == 3)
    {
    label.text = @"Downloading..."

    count = 1;
    }
}

whenever you want to stop Updating do this,in scenario you want to stop downloding :

[timer invalidate];

Answer 3

Use this. It may help you..

if (!timer)
{
      timer = [NSTimer timerWithTimeInterval:0.5 target:self selector:@selector(updateLabel) userInfo:nil repeats:YES];
}

Here I add shake animation to indicate downloading progress. Initially the shake values are..

self.shake = 5;
self.direction = 1;

-(void)shake:(UILabel *)theOneYouWannaShake{
    [UIView animateWithDuration:0.01 animations:^
     {
         theOneYouWannaShake.transform = CGAffineTransformMakeTranslation(5*self.directions, 0);
     }
                     completion:^(BOOL finished)
     {
         if(self.shakes >= 5)
         {
             theOneYouWannaShake.transform = CGAffineTransformIdentity;
             return;
         }
         self.shakes++;
         self.directions = self.directions * -1;
         [self shake:theOneYouWannaShake];
     }];
}

- (void) updateLabel {
    int status = self.count % 3;
    if(status == 0)
      {
        label.text = @"Downloading."
      }
     else if(status == 1)
     {
        label.text = @"Downloading.."
     }
     else 
    {
       label.text = @"Downloading...";

    } 
     self.count += 1 ;
}

After download complete.

[timer invalidate]
self.count = 0;

Answer 4

In viewDidLoad:

self.downloadingLabel.text = @"downloading.";

[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(tick:) userInfo:nil repeats:YES];

Then add the method:

- (void) tick:(NSTimer *) timer {
    if ([self.downloadingLabel.text isEqual: @"downloading..."])
        self.downloadingLabel.text = @"downloading.";
    else
        self.downloadingLabel.text = [self.downloadingLabel.text stringByAppendingString:@"."];
}

This will do what you asked for. Although you may want to look into classes like UIActivityIndicatorView;

Answer 5

I just came to this post in 2015 and I wasn't satisfied with the answers here. Here's my solution. Change the 4 for as many dots as you want. This will do 3 dots ( 4 - 1 ). Change the word Posting to whatever status you need.

First add a timer as stated above.

self.ellipsisTimer = [NSTimer scheduledTimerWithTimeInterval:0.6
                                              target:self
                                            selector:@selector(updateLabelEllipsis:)
                                            userInfo:nil
                                             repeats:YES]; 

In your update method:

- (void) updateLabelEllipsis:(NSTimer *)timer {
    NSString *messageText = [[self messageLabel] text];
    NSInteger dotCount = messageText.length - [[messageText stringByReplacingOccurrencesOfString:@"." withString:@""] length] + 1;
    [[self messageLabel] setText:@"Posting"];
    NSString *addOn = @".";
    if (dotCount < 4) {
        addOn = [@"" stringByPaddingToLength:dotCount withString: @"." startingAtIndex:0];
    }
    [[self messageLabel] setText:[[[self messageLabel] text] stringByAppendingString:addOn]];
}

It works by counting the current number of dots and adding one more. Once it goes above the limit it goes back to 1 dot.

Answer 6

Updated Johnston 's answer for Swift:

ellipsisTimer = NSTimer.scheduledTimerWithTimeInterval(0.6, target: self, selector: #selector(LinkCheckViewController.updateLabelEllipsis(_:)), userInfo: nil, repeats: true)



func updateLabelEllipsis(timer: NSTimer) {
        let messageText: String = self.ThreeDotLabel.text!
        let dotCount: Int = (ThreeDotLabel.text?.characters.count)! - messageText.stringByReplacingOccurrencesOfString(".", withString: "").characters.count + 1
        self.ThreeDotLabel.text = " "
        var addOn: String = "."
        if dotCount < 4 {
            addOn = "".stringByPaddingToLength(dotCount, withString: ".", startingAtIndex: 0)
        }
        self.ThreeDotLabel.text = self.ThreeDotLabel.text!.stringByAppendingString(addOn)
    }

Answer 7

Change the UILabel text animation of 0.5 seconds duration with adding 3 texts in array and updating all the time until your response succeed.

User NSTimer for updating UILabel text