我已经拖网了几天，试图找到关于如何在Swift中以程序方式绘制矩形或线条的最简单的代码示例。我已经看到如何通过覆盖DrawRect命令来做到这一点。我相信你可以创建一个CGContext然后绘制一个图像，但我很乐意看到一些简单的代码示例。还是这是一个可怕的做法？谢谢。
class MenuController: UIViewController
{
override func viewDidLoad()
{
super.viewDidLoad()
// Do any additional setup after loading the view,typically from a nib.
self.view.backgroundColor = UIColor.blackColor()
var logoFrame = CGRectMake(0,118,40)
var imageView = UIImageView(frame: logoFrame)
imageView.image = UIImage(named:"logo")
self.view.addSubview(imageView)
//need to draw a rectangle here
}
}
这是一个创建一个包含透明背景和一个红色矩形的自定义UIImage的例子，线条通过对角线对齐。
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad();
let imageSize = CGSize(width: 200,height: 200)
let imageView = UIImageView(frame: CGRect(origin: CGPoint(x: 100,y: 100),size: imageSize))
self.view.addSubview(imageView)
let image = drawCustomImage(imageSize)
imageView.image = image
}
}
func drawCustomImage(size: CGSize) -> UIImage {
// Setup our context
let bounds = CGRect(origin: CGPoint.zeroPoint,size: size)
let opaque = false
let scale: CGFloat = 0
UIGraphicsBeginImageContextWithOptions(size,opaque,scale)
let context = UIGraphicsGetCurrentContext()
// Setup complete,do drawing here
CGContextSetStrokeColorWithColor(context,UIColor.redColor().CGColor)
CGContextSetLineWidth(context,2.0)
CGContextStrokeRect(context,bounds)
CGContextBeginPath(context)
CGContextMoveToPoint(context,CGRectGetMinX(bounds),CGRectGetMinY(bounds))
CGContextAddLineToPoint(context,CGRectGetMaxX(bounds),CGRectGetMaxY(bounds))
CGContextMoveToPoint(context,CGRectGetMaxY(bounds))
CGContextStrokePath(context)
// Drawing complete,retrieve the finished image and cleanup
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
