按比例空间定位对象

Posted 2023-02-23

【中文标题】按比例空间定位对象

【英文标题】：space position objects by proportion

【发布时间】：2020-03-06 04:45:32

【问题描述】：

我下面的快速代码是定位对象。我希望两个对象都覆盖 x 轴的 10%。所以第一个对象是fight[0].image，第二个对象是fight1.image。正如您在左侧的图像中看到的那样，下面的当前代码正在生成。右边的图像是我希望代码生成的。由于我不能约束下面的代码，我不知道如何实现这个结果。所以fight[0].image 应该覆盖x 轴的10%，然后fight1.image 应该覆盖x 轴的下一个10%。这 2 个对象加起来应该覆盖 x 轴的 20%。

import UIKit

class ViewController: UIViewController 


    let fight = (0..<10).map  _ in UIImageView() 
    var textEnter = UITextField()
    var g2 = UIPanGestureRecognizer()
    var g3 = UIPanGestureRecognizer()


    override func viewDidLoad() 
        super.viewDidLoad()

        fight[0].image  = UIImage(named: "a.png")
        fight[1].image  = UIImage(named: "m.png")
        fight.forEach
            $0.isUserInteractionEnabled = true
        
        [textEnter].forEach
            $0.translatesAutoresizingMaskIntoConstraints = false
            view.addSubview($0)
            $0.backgroundColor = .blue
        



        g2 = UIPanGestureRecognizer(target: self, action: #selector(ViewController.g1Method))
        g3 = UIPanGestureRecognizer(target: self, action: #selector(ViewController.g1Method))


        fight[0].addGestureRecognizer(g2)
        fight[1].addGestureRecognizer(g3)


        fight.forEach
            $0.backgroundColor = .clear
            view.addSubview($0)

        


        // need a non-rendering "spacer" to vertically separate textEnter from Pic
        let spacer = UILayoutGuide()
        view.addLayoutGuide(spacer)

        // NOTE: do NOT constrain any elements relative to fight views

        NSLayoutConstraint.activate ([

            // constrain textEnter top / leading / trailing to view
            textEnter.topAnchor.constraint(equalTo: view.topAnchor, constant : 0),
            textEnter.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant : 0),
            textEnter.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant :0),
            // constrain textEnter height to 0.1 * view height
            textEnter.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.1, constant: 0),

            // constrain spacer top to bottom of textEnter
            spacer.topAnchor.constraint(equalTo: textEnter.bottomAnchor, constant: 0.0),
            // constrain spacer leading to view leading
            spacer.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0.0),
            // constrain spacer height to 0.1 * view height
            spacer.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.10),
            // spacer width doesn't matter
            spacer.widthAnchor.constraint(equalToConstant: 1.0),



        ])

        textEnter.textAlignment = .center



    

    override func viewDidAppear(_ animated: Bool) 
        super.viewDidAppear(animated)
        // set fight[0] frame *after* textEnter has been laid-out
        fight[0].frame.size = CGSize(width: view.frame.width * 0.10, height: view.frame.height * 0.10)
        let x = view.frame.origin.x
        let y = textEnter.frame.origin.y + textEnter.frame.size.height
        fight[0].frame.origin = CGPoint(x: x, y: y)



        fight[1].frame.size = CGSize(width: view.frame.width * 0.10, height: view.frame.height * 0.10)
        let x1 = view.frame.origin.x * 0.10
        let y1 = textEnter.frame.origin.y + textEnter.frame.size.height
        fight[1].frame.origin = CGPoint(x: x1, y: y1)
    

【参考方案1】：

您可能希望您的fight 图像视图是方形的（因此图像将是圆形的），因此计算一次宽度为：

let w = view.frame.width * 0.10

并将高度设置为与宽度相同的值

let h = w

您将从y 开始作为textEnter 的底部，x 作为0，然后循环遍历fight 数组中的图像视图，设置框架并将x 递增w:

override func viewDidAppear(_ animated: Bool) 
    super.viewDidAppear(animated)
    // set fight frames *after* textEnter has been laid-out

    // width should be 10% of view width
    let w = view.frame.width * 0.10

    // height should be the same as width
    let h = w

    // start x-position at 0
    var x: CGFloat = 0

    // y-position is bottom of textEnter frame
    let y = textEnter.frame.origin.y + textEnter.frame.size.height

    // set frames for all imageViews in fight array
    fight.forEach  v in
        // set the frame
        v.frame = CGRect(x: x, y: y, width: w, height: h)
        // increment x by the width
        x += w
    

您现在将有 10 个 fight 图像视图在视图中对齐（我使用随机颜色作为背景）：