objective c resizing mask

Question

i have a view within 3 Buttons. My problem is, how can i set the resizing mask or autolayout programmatically that i get this solution:

Small view and a larger view..

Objective-c code:

_button1 = [UIButton buttonWithType:UIButtonTypeCustom];
[_button1 setFrame:CGRectMake(0, 0, self.view.frame.size.width, 70)]; // set a height?!
[_button1 setBackgroundColor:[UIColor colorWithRed:235/255.0f green:235/255.0f blue:235/255.0f alpha:1.0f]];
_button1.autoresizingMask = UIViewAutoresizingFlexibleHeight;

_button2 and_button3 are the same..

How can i set the button height flexible in dependence of the view height?

Thanks for helping..

Answer 1

An example of how you might achieve this using AutoLayout might look like this:

// Build the view hierarchy
_button1 = [UIButton buttonWithType:UIButtonTypeCustom];
[_button1 setBackgroundColor:[UIColor colorWithRed:235/255.0f green:235/255.0f blue:235/255.0f alpha:1.0f]];
_button1.translatesAutoresizingMaskIntoConstraints = NO;
_button2 = [UIButton buttonWithType:UIButtonTypeCustom];
[_button2 setBackgroundColor:[UIColor colorWithRed:235/255.0f green:235/255.0f blue:235/255.0f alpha:1.0f]];
_button2.translatesAutoresizingMaskIntoConstraints = NO;
_button3 = [UIButton buttonWithType:UIButtonTypeCustom];
[_button3 setBackgroundColor:[UIColor colorWithRed:235/255.0f green:235/255.0f blue:235/255.0f alpha:1.0f]];
_button3.translatesAutoresizingMaskIntoConstraints = NO;

[self.view addSubview: _button1];
[self.view addSubview: _button2];
[self.view addSubview: _button3];

NSMutableArray* constraints = [NSMutableArray array];

// Arrange them vertically
[constraints addObjectsFromArray: [NSLayoutConstraint constraintsWithVisualFormat: @"V:|-[_button1]-[_button2]-[_button3]-|" options:0 metrics:nil views: NSDictionaryOfVariableBindings(_button1, _button2, _button3)]];

// Make their heights equal
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button1 attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem: _button2 attribute: NSLayoutAttributeHeight multiplier:1.0 constant:0.0]];
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button1 attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem: _button3 attribute: NSLayoutAttributeHeight multiplier:1.0 constant:0.0]];

// Set their widths equal to superview
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button1 attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem: self.view attribute: NSLayoutAttributeWidth multiplier:1.0 constant:0.0]];
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button2 attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem: self.view attribute: NSLayoutAttributeWidth multiplier:1.0 constant:0.0]];
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button3 attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem: self.view attribute: NSLayoutAttributeWidth multiplier:1.0 constant:0.0]];

// Center them horizontally in the superview
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button1 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem: self.view attribute: NSLayoutAttributeCenterX multiplier:1.0 constant:0.0]];
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button2 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem: self.view attribute: NSLayoutAttributeCenterX multiplier:1.0 constant:0.0]];
[constraints addObject: [NSLayoutConstraint constraintWithItem:_button3 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem: self.view attribute: NSLayoutAttributeCenterX multiplier:1.0 constant:0.0]];

// Add the constraints
[self.view addConstraints: constraints];