masonry example updateConstraints vs remakeConstraints

Question

when I use masonry to layout my view i find that the behavior is quite diffrent between updateConstraints and remakeConstraints

- (id)init {
self.growingButton = [UIButton buttonWithType:UIButtonTypeSystem];
[self.growingButton setTitle:@"Grow Me!" forState:UIControlStateNormal];
self.growingButton.layer.borderColor = UIColor.greenColor.CGColor;
self.growingButton.layer.borderWidth = 3;

[self.growingButton addTarget:self action:@selector(didTapGrowButton:) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:self.growingButton];

self.buttonSize = CGSizeMake(100, 100);

[self.growingButton makeConstraints:^(MASConstraintMaker *make) {
    make.center.equalTo(self);
    make.width.equalTo(@(self.buttonSize.width)).priorityLow();
    make.height.equalTo(@(self.buttonSize.height)).priorityLow();
    make.width.lessThanOrEqualTo(self);
    make.height.lessThanOrEqualTo(self);
}];
...
return self;
}
//click button 
- (void)didTapGrowButton:(UIButton *)button {

self.buttonSize = CGSizeMake(self.buttonSize.width * 1.3, self.buttonSize.height * 1.3);
NSLog(@"===============================");
[self.growingButton updateConstraints:^(MASConstraintMaker *make) {
//    [self.growingButton remakeConstraints:^(MASConstraintMaker *make) {
    make.center.equalTo(self);
    make.width.equalTo(@(self.buttonSize.width)).priorityLow();
    make.height.equalTo(@(self.buttonSize.height)).priorityLow();
    make.width.lessThanOrEqualTo(self);
    make.height.lessThanOrEqualTo(self);
}];
}

when i use updateConstraints,the button will grow as expected, but when i use remakeConstraints,the button's frame remains "NSRect: {{127, 237}, {66, 30}}"

i wonder why?

Answer 1

Here is an explanation from an issue reported on the GitHub page for Masonry. https://github.com/SnapKit/Masonry/issues/81

mas_updateConstraints: is suitable for lightweight updates where you only need to change a constraint constant.

mas_remakeConstraints: method which uninstalls all constraints previously created for this view.

The complete uninstallation of all the constraints could be causing the difference in outcomes.