iOS - Moving view does not animate - ios

I have toolbar on my view and I want to move it with animation, but the animation does not work, the toolbar move quickly to the new position. I use it:
[UIView animateWithDuration:2.0f animations:^{
[self.view layoutIfNeeded];
self.toolbarBottomLayoutConstraint.constant = editing ? 0 : -44;
}];
Does anybody know why?

I've tried just changing animation block sentences and it worked for me:
[UIView animateWithDuration:2.0 animations:^{
self.bottomMargin.constant = editing ? 0 : -44;
[self.view layoutIfNeeded];
}];

Why don't you do something like this?
[UIView animateWithDuration:2.0f
animations:^{
yourView.center = CGPointMake(yourView.frame.size.width/2, -44);
} completion:^(BOOL finished) {}];

Related

AnimateWithDuration doesn't work as expected

I'm trying to run an example to test this function. I have a label an a button in the storyBoard and I have referenced the bottom constraint of the label in the view controller. When I use the button I want the label to move with an animation but it moves without it. Here's the code of the button:
- (IBAction)sd:(id)sender {
[UIView animateWithDuration:0.5f animations:^{
self.constraint.constant += 50;
}];
}
I know how to use it in swift but I'm having problems in objective c and I know it will be just for a little mistake... Any help?
This is not the right way of animating a UI component constrained with Autolayout. You should first update the constraint, then call layoutIfNeeded within the animation block:
self.constraint.constant += 50;
[UIView animateWithDuration:0.5f animations:^{
[self.view layoutIfNeeded];
}];
Use this
self.constraint.constant += 50;
[UIView animateWithDuration:0.5f
animations:^{
[self.view layoutIfNeeded];
}];
Try this setNeedsLayout helps in some cases.
self.constraint.constant += 50;
[UIView animateWithDuration:0.5f
animations:^{
[self.view setNeedsLayout];
}
completion:^(BOOL finished) {
}];

About 'beginAnimations' and 'commitAnimations'

I added in the button click event:
[UIView beginAnimations:nil context:nil];
sender.titleLabel.font = [UIFont systemFontOfSize:18];
[UIView commitAnimations];
The animation is not working. But if I remove [UIView commitAnimations];, the animation works. Why?
If I don't add [UIView commitAnimations];, what will happen?
Why you are not using this for view animations?
[UIView animateWithDuration:1.0 animations:^{
// place your animations code here
}];
Note: please visit this url and see the section What can be animated. Only few properties can be used for animations
https://developer.apple.com/library/content/documentation/WindowsViews/Conceptual/ViewPG_iPhoneOS/AnimatingViews/AnimatingViews.html
Try this, it will help. In the example below, viewObject may be label in your case.
[UIView animateWithDuration:1.0 animations:^{
viewObject.transform = CGAffineTransformMakeScale(1.5, 1.5);
}];

UIPanGestureRecognizer conflict with constraints animation

I have an animation of a contentView of a cell wish have UIPanGestureRecognizer.
the UIPanGestureRecognizer works fine and detect touches but while the animation is happening it doesn't detect touches until it finish the animation.
is there a workaround for this.
this is the animation block
[self.myContentView layoutIfNeeded];
self.contentViewLeftConstraint.constant = -50;
self.contentViewRightConstraint.constant = 50;
[UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
[self.myContentView layoutIfNeeded];
} completion:completion];
Thanks.
If you want to allow user interaction during the animation, you must set the option to allow it:
UIViewAnimationOptions options = UIViewAnimationOptionCurveEaseOut |
UIViewAnimationOptionAllowUserInteraction;
[UIView animateWithDuration:duration delay:0 options:options animations:^{
[self.myContentView layoutIfNeeded];
} completion:completion];

Different animation duration for subviews of an UIView

I have the following code
[UIView animateWithDuration:2 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
mainPage.frame=CGRectMake(0, -[UIScreen mainScreen].bounds.size.width,[UIScreen mainScreen].bounds.size.height,[UIScreen mainScreen].bounds.size.width);
} completion:nil];
Is there any way to control the animation duration of the subviews of mainPage.
You can use UIView:animateKeyframesWithDuration then use UIView:addKeyframeWithRelativeStartTime to set its start time and duration
[UIView animateKeyframesWithDuration:2 delay:0 options:0 animations:^{
[UIView addKeyframeWithRelativeStartTime:0.32 relativeDuration:0.68 animations:^{
view.frame = frame;
}];
[UIView addKeyframeWithRelativeStartTime:0.5 relativeDuration:1 animations:^{
subview.frame = frame2;
}];
} completion:^(BOOL finished) {
}];
If you want the subviews to animate with a different duration then you'll need to animate each of them separately. You can loop through the mainPage.subviews array and issue an animateWithDuration:delay:options:animations:completion: call to each subview in turn, each with a different duration.

How do I have text fade in to a UILabel?

Right now I have an IBAction for a button which generates a random number with each number assigned to display text in a UILabel. Rather than just appear, I would like the text to fade in or any other interesting animation would be cool too. Does anyone know a simple way to make this happen?
Right now I just use
labelMain.text = #"my text";
I know this is a bit stale (11 months old), but I think it's worth mentioning an alternative to the other approaches posted, which I feel is a better solution.
Make use of the UIView transitionWithView:duration:options:animations:completion class-level method, like this:
NSTimeInterval duration = 0.5f;
[UIView transitionWithView:labelMain
duration:duration
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
labelMain.text = #"new value";
} completion:nil];
This will cross-fade from the previous value of labelMain.text to "new value".
This approach works on other view values as well, such as changing the image of a UIImageView, for instance.
See Apple's docs on the topic.
The following code will give you fading effect on your label.
- (IBAction)buttonClicked:(UIButton *)sender
{
labelMain.alpha = 0;
[UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveEaseIn
animations:^{ labelMain.alpha = 1;}
completion:nil];
}
label.text = #"old text";
[UIView animateWithDuration:0.4 animations:^{
label.alpha = 0.0f;
} completion:^(BOOL finished) {
label.text = #"next text";
[UIView animateWithDuration:0.4 animations:^{
label.alpha = 1.0f;
} completion:^(BOOL finished) {
NSLog(#"finished transition");
}];
}];
Try this:
[labelMain setAlpha:0];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.8];
[labelMain setAlpha:1];
[UIView commitAnimations];
Changing the duration is pretty simple - just adjust the value 0.8 in the code.
// fade out the current value
[UIView animateWithDuration:0.2
delay:0
options:0
animations:^{
labelMain.alpha = 0.0f;
}
completion:^(BOOL finished) {
// set the new value and fade in
labelMain.text = newValue;
[UIView animateWithDuration:0.2
delay:0
options:0
animations:^{
labelMain.alpha = 1.0f;
}
completion:nil];
}];
This will look like cross fade animation
[UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveEaseOut
animations:^{
labelMain.alpha = 0;
[UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveEaseIn
animations:^{ labelMain.alpha = 1;}
completion:nil];
} completion:nil];

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