constraintsWithVisualFormat

    [btnShare setTranslatesAutoresizingMaskIntoConstraints:NO];
    NSDictionary *metrics = @{@"height":@44.0
                              , @"width":@44.0
                              , @"edgeSpace":@10.0};
    NSDictionary *views = NSDictionaryOfVariableBindings(button);
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[button(width)]-edgeSpace-|" options:0 metrics:metrics views:views]];
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-edgeSpace-[button(height)]" options:0 metrics:metrics views:views]];