自动版式：无法同时满足约束条件日志不明确

Question

I'm getting the usual Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. ... Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. ... Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. ... warning in the console.

One of the constraints in the list is:

"<NSLayoutConstraint:0x7fe7bda00ff0 MyView:0x7fe7bbc934f0.height ==>"

Now, the meaning of the warning itself is pretty clear: some of the constraints are clashing and the engine is unable to satisfy all of them. This is pretty common when setting constraints via code, as I'm doing in this instance.

What's not clear to me is the meaning of that specific constraint. What does the missing right part of the equality means?

My guess is that is means that the height depends on the constraints set by its subviews. Is this correct?

Answer 1

In your constraints there is an extra constraints that not require.

For example,

Suppose you given a constraints to leading and trailing and also you are giving a width constraints that this will lead to the warning to the compiler. because either you need a constraints for width or trailing constraints otherwise compiler will confuse what to take width or trailing.

For auto layout you need to remember one thing for any view you need to make constrains like this that compiler knows about view x , y , width and height.