When I add some animations on the subview of the scrollview that like extending or contract a textfield,it just not work. But it worked well when the subview add to a simple UIView.
How did it happen?
There should be no problem animating the frame of a UITextField within a UIScrollView.
The most common source of "my animation isn't animating" in iOS 6 and later is the attempt to animate a control by adjusting the frame when employing autolayout (because the adjustment of the frame can be thwarted by the constraints being reapplied by the most innocuous of actions). You can tell if you're using autolayout or not by selecting the File Inspector (the first tab) of the rightmost panel in Interface Builder, and seeing if "Use Autolayout" is checked:
For example, to animate the frame when not using autolayout, assuming your UITextField has an IBOutlet called textField, you might do something like:
[UIView animateWithDuration:0.5 animations:^{
CGRect frame = self.textField.frame;
frame.size.width = 280;
self.textField.frame = frame;
}];
But the equivalent when using autolayout is not achieved by adjusting the frame, but rather by changing the constraints' constant values. For example, assuming you created an IBOutlet for the width constraint called textFieldWidthConstraint on your UITextField, you would animate the changing of the width with something like:
self.textFieldWidthConstraint.constant = 280;
[UIView animateWithDuration:0.5 animations:^{
[self.view layoutIfNeeded];
}];
If you believe you are using the appropriate animation technique that corresponds to your choice of autolayout or non-autolayout, but it's still not working, you should show us some code and describe the situation in greater detail.
Related
I have an imageview I put onto the view controller of a circle.
I would like to start that circle from off screen and move it to the location I've put it.
What would be the best way to animate it?
Try this;
-(void)viewWillAppear {
[UIView animateWithDuration:5
delay:5
options:UIViewAnimationOptionCurveEaseOut
animations:^{
CGRect frame = view.frame;
frame.origin.y = self.view.frame.size.height-200;
frame.origin.x = 0;
view.frame = frame;
}completion:^(BOOL finished) {}];
}
You many animation option's [UIViewAnimationOptions]
UIViewAnimationOptionCurveEaseInOut,
UIViewAnimationOptionCurveLinear,
UIViewAnimationOptionTransitionFlipFromLeft,
UIViewAnimationOptionTransitionCurlUp,
UIViewAnimationOptionTransitionCrossDissolve,
UIViewAnimationOptionTransitionFlipFromTop..
You want to create your image view off-screen. Its easiest if you set it up in Interface Builder that way. you can create it on-screen, add a constraint to place it at the target location, note the value, and then change the constraint's constant so the view is moved off-screen.
Then control-drag the constraint into your view controller and create an outlet to it.
To animate the image view on-screen, change the constraint's constant value to the "on-screen" value you noted above, and then call layoutIfNeeded() on the view from inside an a UIView animateWithDuration block.
If you want to add the image view in code then you need to add it off-screen, add it as a subview, and then trigger a UIView animation to move it back on-screen. You should probably also do the positioning with constraints as outlined above, although it gets more complicated because you have to create those constraints in code.
I'm using Objective-C. And I want to make the table view move down with animation when I add a search bar above it. This is my code(table here is my table view):
[UIView animateWithDuration:0.3 animations:^{
CGRect frame = self.table.frame;
frame.origin.y = frame.origin.y+30;
self.table.frame = frame;
}];
But it doesn't work. Someone can help me?
Add layoutIfNeeded at the end of animation block. Like that:
[UIView animateWithDuration:0.3 animations:^{
CGRect frame = self.table.frame;
frame.origin.y = frame.origin.y+30;
self.table.frame = frame;
[self.view layoutIfNeeded];
}];
Changing frames like this is not the best way to do it, and its old fashioned. The best way is to get access to one of the autolayout constraints on the view, and change it. For eg - say your tableview has a top constraint that defines the gap between the top of the tableview and the superview - eg 10px. Drag that constraint from IB, into your class. Best way to do this is to highlight the constraint on the left hand side of IB, in the list that contains all your views etc. Drag across to make it a property in your class, just like you do with a button or label. Then at runtime, you change the .constant property of that constraint. For eg. Heres my NSLayoutConstraint property when dragged across into the class :
#property (weak, nonatomic) IBOutlet NSLayoutConstraint *topBuffer;
Then at the point in code where you want the move to happen, you change the constant property, OUTSIDE of the animation call :
self.topBuffer.constant = 50; //<-- or whatever the new value is
Then all you do is call [self.view layoutIfNeeded] in the animation block. By the way - note here Ive used the anim block with springs etc for a bouncey effect too. Also note - layoutIfNeeded is called on the superview of the object you are changing - so self.view here is my main superview that contains the tableview.
[UIView animateWithDuration:0.7f delay:0 usingSpringWithDamping:1.0 initialSpringVelocity:0 options:UIViewAnimationOptionCurveEaseIn animations:^(void) {[self.view layoutIfNeeded];} completion:nil];
I have a view that automatically adjusts it's height based on number of lines in a UILabel within the view. There is another view which height is pinned to be equal to the view with the label.
I would like to animate the height change caused by setting long text to the label, thus changing the number of lines and causing autolayout constraints to recalculate height. This new height will change the height of the second view too. How can I animate autolayout changes that happen as a side effect of property assignment?
I tried this, but it did not work:
[UIView animateWithDuration:0.3 animations:^{
//I want the side effect of this assignment to be animated
self.viewWithLabel.title = #"This long title will change the view height and cause layout change";
}];
See the documentation
Try:
- (void)viewDidAppear:(BOOL)animated {
[self.view layoutIfNeeded];
[UIView animateWithDuration:1.0 animations:^{
self.viewWithLabel.title = #"This long title will change the view height and cause layout change";
[self.view layoutIfNeeded];
}];
}
I think you want yourTextLabel.clipToBounds = YES also.
If you want more advanced effect, see this question.
I have a UIViewController with a UICollectionView and a UIView at the bottom. The way I put it together is displayed in the image below
The yellow square is the UICollectionView and the red is the UIView. This works out just fine. But now I want to resize the UIView because it sometimes contains more info and needs to be bigger. So I tried this:
[self setFrame:CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, self.frame.size.height + 10)];
But this expands the UIView at the bottom and it is not visible. I guess this is because I do not have the correct constraints? I also tried to subtract the origin.y with the same amount and this works only the UICollectionView doesn't get resized with the new height. So how do I tackle this problem?
If you are using autolayout, you should not be setting the frame from your code. Instead you should modify the constant of a constraint that is causing your view to be the incorrect size. You can have an IBOutlet to that constraint and you can change it's constant property. Then call setNeedsLayout on your view controller's view
When setting constraints on your storyboard or in a xib file, animations perform animations on the constraints instead of the sizes and positions.
First create a outlet reference of the constraint which will change (in your case the top space of your UIView to the top layout guide) in the header file of your view controller.
When you want to animate a view, you now have to update its constraints and ask to layout the views.
For example :
[UIView animateWithDuration:0.2
animations:^{
viewYConstraint.constant -= 44;
[self.view layoutIfNeeded];
}
]
//Now don't forget to update constraints
[self.view updateConstraints];
I've never worked with autolayout constraints before. I have a small new app I'm working on and noticed that the NIB's views are defaulting to autolayout. So, I figured I'd take the opportunity to work with it and try to figure out where Apple is going with this.
First challenge:
I need to resize an MKMapView and I'd like to animate it to the new position. If I do this the way I'm used to:
[UIView animateWithDuration:1.2f
animations:^{
CGRect theFrame = worldView.frame;
CGRect newFrame = CGRectMake(theFrame.origin.x, theFrame.origin.y, theFrame.size.width, theFrame.size.height - 170);
worldView.frame = newFrame;
}];
...then the MKMapView will 'snap' back to its original height whenever a sibling view gets updated (in my case a UISegmentedControl's title is being updated [myUISegmentedControl setTitle:newTitle forSegmentAtIndex:0]).
So, what I think I want to do is change the constraints of the MKMapView from being equal to the parent view's hight to being relative to the top of the UISegmentedControl that it was covering: V:[MKMapView]-(16)-[UISegmentedControl]
What I want is for the MKMapView height to shorten so that some controls beneath the map view are revealed. To do so I think I need to change the constraint from a fixed full size view to one where the bottom is constrained to the top of a UISegmentedControl...and I'd like it to animate as view shrinks to new size.
How does one go about this?
Edit - this animation is not animating though the bottom of the view does move up 170 instantly:
[UIView animateWithDuration:1.2f
animations:^{
self.nibMapViewConstraint.constant = -170;
}];
and the nibMapViewConstraint is wired up in IB to the bottom Vertical Space constraint.
After updating your constraint:
[UIView animateWithDuration:0.5 animations:^{[self.view layoutIfNeeded];}];
Replace self.view with a reference to the containing view.
This works for me (Both iOS7 and iOS8+). Click on the auto layout constraint you would like to adjust (in interface builder e.g top constraint). Next make this an IBOutlet;
#property (strong, nonatomic) IBOutlet NSLayoutConstraint *topConstraint;
Animate upwards;
self.topConstraint.constant = -100;
[self.viewToAnimate setNeedsUpdateConstraints];
[UIView animateWithDuration:1.5 animations:^{
[self.viewToAnimate layoutIfNeeded];
}];
Animate back to original place
self.topConstraint.constant = 0;
[self.viewToAnimate setNeedsUpdateConstraints];
[UIView animateWithDuration:1.5 animations:^{
[self.viewToAnimate layoutIfNeeded];
}];
There is a very good tutorial from apple itself that explain how to use animation with autolayout.
Follow this link and then find the video named "Auto layout by example"
It gives some interesting stuff about autolayout and the last part is about how to use animation.
I have made this small demo available. It shows how auto-layout constraints can be changed and animated in a very simple example. Simply take a look at the DemoViewController.m.
Most people use autolayout to layout items on their views and modify the layout constrains to create animations.
An easy way to do this without a lot of code is creating the UIView you want to animate in Storyboard and then creating a hidden UIView where you want the UIView to end. You can use the preview in xcode to make sure both UIViews are where you want them to be. After that, hide the ending UIView and swap the layout constraints.
There is a podfile for swapping layout constrains called SBP if you don't want to write it yourself.
Here's a tutorial.
No need to use more IBOutlet reference of the constraint instead of this you can directly access or update already applied constraint either applied by Programmatically or from Interface Builder on any view using the KVConstraintExtensionsMaster library. This library is also managing the Cumulative behavior of NSLayoutConstraint.
To add Height Constraint on containerView
CGFloat height = 200;
[self.containerView applyHeightConstrain:height];
To update Height Constraint of containerView with animation
[self.containerView accessAppliedConstraintByAttribute:NSLayoutAttributeHeight completion:^(NSLayoutConstraint *expectedConstraint){
if (expectedConstraint) {
expectedConstraint.constant = 100;
/* for the animation */
[self.containerView updateModifyConstraintsWithAnimation:NULL];
}
}];