How to position activity indicator to the center of its superview using Auto Layout programmatically?

Question

Why the following code does not work for positioning activity indicator to the center of its superview:

UIActivityIndicatorView *activityIndicator = [[UIActivity         


        

Answer 1

You can try this,

 UIView *superview = self.mysuperview;
NSDictionary *variables = NSDictionaryOfVariableBindings(activityIndicator, superview);
NSArray *constraints =
[NSLayoutConstraint constraintsWithVisualFormat:@"V:[superview]-(<=1)-[activityIndicator]"
                                        options: NSLayoutFormatAlignAllCenterX
                                        metrics:nil
                                          views:variables];
[self.view addConstraints:constraints];

constraints =
[NSLayoutConstraint constraintsWithVisualFormat:@"H:[superview]-(<=1)-[activityIndicator]"
                                        options: NSLayoutFormatAlignAllCenterY
                                        metrics:nil
                                          views:variables];
[self.view addConstraints:constraints];

Taken from here.