iOS：如何正确获取水平堆叠视图内按钮的约束？

Question

I am new to iOS development and am following the udacity course for iOS development. I am stuck at the lesson whose link I have given below.

https://classroom.udacity.com/courses/ud585/lessons/6991272849/concepts/72642287220923#

I am unable to reduce the size of stop button in the last stack view. I tried reducing the size of the button by setting the width constraint of the button to 64 and height of stack-view containing that button to 64. But XCode gives error of conflicting constraints.

I am attaching screenshots below for reference.

What I actually want is:

https://d17h27t6h515a5.cloudfront.net/topher/2016/November/582a8006_interface/interface.png

Answer 1

You can take a uiview inside your last stack and then You can take your stop button. Then you can change properties of your "stop" UIbutton.

Answer 2

Another option if you want to keep the existing constraints you have in the screenshot from the course is to change the properties of the stack in Interface builder.

For topmost stack

set alignment to fill, and distribution to fill proportionally.

For your stack at bottom with button in it -

set alignment to centre and distribution equal centering.

Answer 3

You may be getting the conflicting constraints because when you tried to "change" the height and width you actually added additional height and width constraints. Check them in the measurements editor and if your see constraints with the >= symbol, you should delete those. Click edit on the height and width remaining to make the changes. This should fix the problem. You may need to clean and build as well.

Hope that helps!