UIView animated changes with auto layout constraints

Question

Say that I have a project which looks like the following:

There are tw

Answer 1

//
//  WPViewController.h
//  AutoLayoutTEst
//
//  Created by VASANTH K on 09/01/14.
//  
//

#import <UIKit/UIKit.h>

@interface WPViewController : UIViewController
@property (strong, nonatomic) IBOutlet UIButton *button1;
- (IBAction)buttClicked:(id)sender;
@property (strong, nonatomic) IBOutlet NSLayoutConstraint *heightConstrain;

@property (strong, nonatomic) IBOutlet UIButton *button2;
@end

click Event

- (IBAction)buttClicked:(id)sender {


    self.heightConstrain.constant=100;


}

here u need to set the heightConstrain for the Yellow button then create reference outlet for that button then update the heightConstrain to update the size of that button it will automatically move your Red button down.

https://github.com/vasanth3008/AutoLayoutHeighDemo

refer my sample demo project

Answer 2

Try it as mentioned by shwet-solanki, but add the following line after changing the constraint:

[self.view layoutIfNeeded];

the IBAction would look like:

- (IBAction)expandYellowBox:(id)sender {

[UIView animateWithDuration:0.5
                 animations:^{
                     self.yellowBoxHeightConstraint.constant += 50;
                     [self.view layoutIfNeeded];
                 }];
}

Where yellowBoxHeightConstraint is the IBOutlet for height constraint of yellowBox. Hope this helps.

Answer 3

1. Add Height constraint to both the views
2. Create an IBOutlet for height constraint of yellowbox
3. Now instead of changing the height of yellowbox in the button pressed event, rather change the value of the height constraint. i.e suppose your IBOutlet constraint name is yellowBoxHeightConstraint, then yellowBoxHeightConstraint.constant += 50;

Hope this works for you.