如何使用Xcode在操场上画圆

Question

I'm working on a school project using Xcode and for part of it, I need to draw a circle on Xcode using Swift. How do I do that?

Answer 1

The first thing you need to do is decide how large of a circle you want – this will determine the parameters you set. The first thing you do is make a constant named whatever you want and make it a square. Then, you can use variableName.layer.cornerRadius to make your circle. You have to use half of what you made the square as it is the radius of the circle.

Here's an example of a circle with a 10 radius:

let circle = UIView(frame: CGRect(x:0, y:0, width: 20, height: 20))

circle.backgroundColor = UIColor.blue //this is just so the circle is visible

circle.layer.cornerRadius = 10

The really important thing to remember is that the square that you originally make must have the width and height be twice the size of the radius. Also, if you are having trouble seeing the circle then it might be because you didn't set a background color to it, so do something like the code above by setting the color to anything you want

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