How to update the constant height constraint of a UIView programmatically?

Question

I have a UIView and I set the constraints using Xcode Interface Builder.

Now I need to update that UIView instance\'s height constant progra

Answer 1

If you have a view with multiple constrains, a much easier way without having to create multiple outlets would be:

In interface builder, give each constraint you wish to modify an identifier:

Then in code you can modify multiple constraints like so:

for constraint in self.view.constraints {
    if constraint.identifier == "myConstraint" {
       constraint.constant = 50
    }
}
myView.layoutIfNeeded()

You can give multiple constrains the same identifier thus allowing you to group together constrains and modify all at once.