AutoLayout, Unable to simultaneously satisfy constraints

Question

Just started learning iOS AutoLayout, Interface builder very straight forward, but when I try to archive the same thing on the code

    [self.view addConstr         


        

Answer 1

It may be not so difficult.The message console output says that the UIButton's constraints redefined.It means just like that you put a constraint that restrict the Height and the Width of the button, but needlessly you put another restriction that the button has a Aspect Ratio.In this condition Xcode can't make sure which constraint to follow,so that you can see this debug message in console.

There are two ways Useful for me:

1. Analyse the constraints displayed in the console,and try to delete one or more constraint.

2.If you are using the storyboard or Xib ,Select a constraint ->Show the Attributes Inspector -> change the priority of some Constraints.

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One more thing...

You can follow the article of Jason Jarrett. Add a symbol breakpoint to make sure which view make the error happen.