Auto layout equal space between UIButtons [duplicate]

Answer 1

The only way I've found to do this with IB is to create spacer views between the views that you want to distribute evenly, with all of their edges connected to the neighboring edges of the views that you want to distribute evenly. You give them variable width/height, and then add constraints that say that all of the spacer views must have the same width/height.

It's very tedious to set up, but it does work.

Answer 2

As Duncan C said in his answer, using spacer views is the way to go. In case you want to do it in code, here is some code I've used in the past to create buttons that are equally spaced.

-(void)viewDidLoad {
    [super viewDidLoad];

    NSMutableDictionary *viewsDict = [NSMutableDictionary dictionary];
    NSArray *titles = @[@"Short",@"Longer",@"Short",@"The Longest"];
    for (int i=1; i<5; i++) {
        UIButton *b = [UIButton buttonWithType:UIButtonTypeSystem];
        [b setTitle:titles[i-1] forState:UIControlStateNormal];
        [b setTranslatesAutoresizingMaskIntoConstraints:NO];
        [viewsDict setObject:b forKey:[NSString stringWithFormat:@"b%d",i]];
    }

    for (int i=1; i<6; i++) {
        UILabel *l = [[UILabel alloc ]init]; // these labels are the spacers
        [l setTranslatesAutoresizingMaskIntoConstraints:NO];
        [viewsDict setObject:l forKey:[NSString stringWithFormat:@"l%d",i]];
    }

    for (id obj in viewsDict.allKeys)
        [self.view addSubview:viewsDict[obj]];

    NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|[l1][b1][l2(==l1)][b2][l3(==l1)][b3][l4(==l1)][b4][l5(==l1)]|"
                                                                   options:NSLayoutFormatAlignAllBaseline
                                                                   metrics:nil
                                                                     views:viewsDict];

    NSArray *constraints2 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:[b1]-|"
                                                                    options:0
                                                                    metrics:nil
                                                                      views:viewsDict];


    [self.view addConstraints:constraints];
    [self.view addConstraints:constraints2];
}