三角形 UIView - Swift [英] Triangle UIView - Swift

问题描述

所以我正在制作一个游戏，在这个游戏中，我丢弃了必须由用户在屏幕底部的尖峰(三角形)破坏的对象.

So I'm making a game in which I am dropping objects which have to be destroyed by a spike(triangle) at the bottom of the screen by a user.

我不知道如何制作一个三角形的 UIView.但是我已经能够使它像这样的矩形工作:

I cannot work out how to make a UIView that is a triangle. However I have been able to make it work as a rectangle like this:

 let barrier = UIView(frame: CGRect(x:125, y: 650, width: 130, height:20))
 barrier.backgroundColor = UIColor.orangeColor()
 view.addSubview(barrier)

这已经奏效了.但我不知道如何制作三角形.我想要它作为 UIView 的原因是因为我在它上面使用了碰撞并让用户移动它.我试过一个 PNG 三角形，但它检测到碰撞是图像的边界而不是三角形的开始.

And this has worked. But I cannot work out how to make a triangle. The reason I want it as a UIView is because im using collisions on it and for the user to move it. I have tried a PNG triangle but it detects the collision as the border of the image not the start of the triangle.

我已经试过了，但它不起作用...

I have tried this but it doesn't work...

 let square = UIView(frame: CGPathMoveToPoint(path, nil, 50, 0), CGPathAddLineToPoint(path, nil, 100, 50), CGPathAddLineToPoint(path, nil, 0, 100))
 square.backgroundColor = UIColor.purpleColor()
 view.addSubview(square)

任何和所有帮助将不胜感激，

Any and all help will be appreciated,

谢谢，

亚历克斯

推荐答案

针对 Swift 3 更新:

Updated for Swift 3:

class TriangleView : UIView {

    override init(frame: CGRect) {
        super.init(frame: frame)
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    override func draw(_ rect: CGRect) {

        guard let context = UIGraphicsGetCurrentContext() else { return }

        context.beginPath()
        context.move(to: CGPoint(x: rect.minX, y: rect.maxY))
        context.addLine(to: CGPoint(x: rect.maxX, y: rect.maxY))
        context.addLine(to: CGPoint(x: (rect.maxX / 2.0), y: rect.minY))
        context.closePath()

        context.setFillColor(red: 1.0, green: 0.5, blue: 0.0, alpha: 0.60)
        context.fillPath()
    }
}

<小时>Swift 2:

import UIKit

class TriangleView : UIView {

    override init(frame: CGRect) {
        super.init(frame: frame)
    }

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    override func drawRect(rect: CGRect) {

        var ctx : CGContextRef = UIGraphicsGetCurrentContext()

        CGContextBeginPath(ctx)
        CGContextMoveToPoint(ctx, CGRectGetMinX(rect), CGRectGetMaxY(rect))
        CGContextAddLineToPoint(ctx, CGRectGetMaxX(rect), CGRectGetMaxY(rect))
        CGContextAddLineToPoint(ctx, (CGRectGetMaxX(rect)/2.0), CGRectGetMinY(rect))
        CGContextClosePath(ctx)

        CGContextSetRGBFillColor(ctx, 1.0, 0.5, 0.0, 0.60);
        CGContextFillPath(ctx);
       }
 } 

这将从MinX，MaxY开始；
从起点到MaxX、MaxY画一条线；
从 MaxX,MaxY 到 MaxX/2, MinY 画一条线；
然后关闭到起始位置的路径.

下一部分设置您要使用的颜色.在这个例子中 255,127,0, Alpha 0.6然后将使用设置的颜色填充您刚刚在上面绘制的路径.

This will start from MinX, MaxY;
Draw a line from the start to MaxX, MaxY;
Draw a line from MaxX,MaxY to MaxX/2, MinY;
Then close the path to the start location.

The next part sets the color you want to use. In this example 255,127,0, Alpha 0.6 Then will fill the path you just drew above with the set color.

然后在您的视图控制器中

Then in your View Controller

Swift 3:

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let triangle = TriangleView(frame: CGRect(x: 10, y: 20, width: 25 , height: 30))
        triangle.backgroundColor = .white
        view.addSubview(triangle)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

<小时>Swift 2:

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let triangle = TriangleView(frame: CGRectMake(10, 20, 25, 30))
        triangle.backgroundColor = .whiteColor()
        view.addSubview(triangle)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

然而，这会导致同样的问题，因为这个视图的框架仍然是一个矩形.UIKit 适用于矩形，您必须使用其他框架，例如 Sprite Kit.

However, this is going to cause the same problem as the frame of this view is still going to be a rectangle. UIKit works with rectangles, you would have to use another framework, like Sprite Kit.

这篇关于三角形 UIView - Swift的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！