Question

我画了一个矩形。当我触摸屏幕时，我可以改变宽度和高度。默认情况下，我使x = 50，y = self.view.frame.height / 2。我需要相对于x和y拉伸矩形。如何更改 x 和 y ？

var scanRectangleRect = CGRect.zero
var scanRectangle: UIView = UIView()


func drawLine() {
    self.view.addSubview(scanRectangle)
    scanRectangle.backgroundColor = UIColor.gray
    scanRectangleRect = CGRect(x: 50, y: self.view.frame.height/2, width: 400, height: 150)

    scanRectangle.frame  = scanRectangleRect
    scanRectangle.center = CGPoint(x: scanRectangle.center.x, y: self.view.frame.height/2)
    scanRectangle.isHidden = false
}

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    scanRectangle.frame.size.height += 10
    scanRectangle.frame.size.width += 10
}

Answer 1

scanRectangle.frame.origin.x += 10
scanRectangle.frame.origin.y += 10

请参阅https://developer.apple.com/documentation/coregraphics/cgrect/1454354-origin

如果你想增加矩形但是把它保持在同一位置的中心位置：

let delta = 10

scanRectangle.frame.origin.x -= delta / 2
scanRectangle.frame.origin.y -= delta / 2
scanRectangle.frame.size.width += delta
scanRectangle.frame.size.height += delta

或

scanRectangle.frame = scanRectangle.frame.insetBy(dx: -10, dy: -10)

Answer 2

let distance: CGFloat = 10
scanRectangle.frame = CGRect(x: scanRectangle.frame.origin.x + distance, 
                             y: scanRectangle.frame.origin.y + distance, 
                         width: scanRectangle.frame.size.width - distance, 
                        height: scanRectangle.frame.size.height - distance)

我认为你的意思是在某个基点上缩放矩形。

Answer 3

scanRectangle.frame.origin.x += 10;
scanRectangle.frame.origin.y += 10;

是你要求的吗？

如何更改CGRect的x和y？

3 个答案: