ios - How draw a line between 2 CGPoint?

Question

I have this code

CGPoint one = [button center];
CGPoint two = [button center];

How draw a line at this points? thanks

I try this

CGContextRef ctx = UIGraphicsGetCurrentContext();



CGContextMoveToPoint(ctx, one.x, one.y);
CGContextAddLineToPoint(ctx, two.x, two.y);
CGContextStrokePath(ctx);

But i have this error:

<Error>: CGContextDrawPath: invalid context 0x0

Answer 1

画线有两种主要方法。

一种方法是创建一个子类UIView并覆盖其drawRect:方法。这在iOS 绘图和打印指南中的“视图绘图周期”中有描述。

另一种方法是使用CAShapeLayer. stackoverflow 上有很多关于使用形状层的答案。看看这个答案作为一个开始。