UIButton按钮自适应排布，自动换行

1.封装一个View用来放所有的button

import UIKit
let SCREEN_WIDTH = UIScreen.main.bounds.size.width
let SCREEN_HEIGHT = UIScreen.main.bounds.size.height
let gap = 10
/// 定义一个代理方法，在实现类里面可以获取到点击的是哪个button，这里是传的index索引，根据需要可以将参数变为button
protocol QYPAdaptiveButtonDelegate:class {
    func searchHistory(index:Int);
}

class QYPAdaptiveButton: UIView {
    weak var delegate:QYPAdaptiveButtonDelegate?
    /// 中间button,记录选中状态
    var tempButton:UIButton?
    /// 按钮的button中文字数组
    var titleArray = [String]()
    /// 正常时候显示的字体大小
    var normal = CGFloat()
    /// 放大时候显示的字体大小
    var bigger = CGFloat()
    /// 设置每一个按钮的高度
    var heightBtn = CGFloat()

    class func creat(frame:CGRect,titleArr:[String],normal:CGFloat = 12,bigger:CGFloat = 15,heightBtn:CGFloat = 30) -> QYPAdaptiveButton{
        let v = QYPAdaptiveButton(frame: frame)
        v.titleArray = titleArr
        v.normal = normal
        v.bigger = bigger
        v.heightBtn = heightBtn
        v.setupUI()
        return v
    }
}
extension QYPAdaptiveButton {
    fileprivate func setupUI(){
        // 定义常量 btn的height + 顶部空隙(没增加一行的高度)
        let rowHeight:CGFloat = heightBtn + 5
        // 定义一个变量,用于记录每一个btn的x值
        let btnX:CGFloat = CGFloat(gap)
        let btnY:CGFloat = 0
        var x:CGFloat = btnX
        var y:CGFloat = btnY
        // 定义一个属性,记录已经是第几行,然后对应的背景view也要需要增加多高
        var index = 0
        
        // 创建证件类型选择按钮
        for i in 0..<titleArray.count {
            let size = titleArray[i].getLabWidth(font: UIFont.systemFont(ofSize: bigger), height: heightBtn)
            if x + size.width > SCREEN_WIDTH {
                index += 1
                x = CGFloat(gap)
                y += rowHeight
            }
            let rect = CGRect(x: x, y: y, width: size.width, height: heightBtn)
            x += size.width + CGFloat(gap)
            let btn = UIButton()
            //2:设置按钮的bg图片与普通图片

            btn.frame = rect
            btn.setTitle(titleArray[i], for: .normal)
            btn.setTitleColor(UIColor.gray , for: .normal)
            btn.setTitle(titleArray[i], for: .selected)
            btn.setTitleColor(#colorLiteral(red: 0.8078431487, green: 0.02745098062, blue: 0.3333333433, alpha: 1), for: .selected)
            btn.titleLabel?.font = UIFont.systemFont(ofSize: normal)
            btn.backgroundColor = UIColor(red:0.95, green:0.95, blue:0.95, alpha:0.5)
            btn.layer.cornerRadius = 8
            btn.tag = 100 + i
            btn.addTarget(target, action: #selector(chooseOCR), for: .touchUpInside)

            btn.titleLabel?.font = UIFont.systemFont(ofSize: normal)
            if i == 0 {
                btn.titleLabel?.font = UIFont.systemFont(ofSize: bigger)
                btn.isSelected = true
                tempButton = btn
            }
            self.addSubview(btn)
        }
        // 重新设置self.height的高度
        self.height += CGFloat(index) * rowHeight + rowHeight
    }
    /// 点击某一个button的时候，通过tag值获取到了对应的button，然后做出对应的响应
    @objc func chooseOCR(btn:UIButton){
        tempButton?.titleLabel?.font = UIFont.systemFont(ofSize: normal)
        tempButton?.isSelected = false
        tempButton = btn
        btn.titleLabel?.font = UIFont.systemFont(ofSize: bigger)
        btn.isSelected = true
        if delegate != nil {
            delegate?.searchHistory(index:btn.tag - 100)
        }
        
    }
}

2.对了还有一个东西没有加上去，就是写的一个获取通过button里面的文字获取到文字的长度来设置button的宽度

extension String {
    /// 通过string动态获取其对应的size
    /// - font: 字体大小
    func getLabWidth(font:UIFont,height:CGFloat) -> CGSize {
        let size = CGSize(width: 900, height: height)
        let dic = NSDictionary(object: font, forKey: NSAttributedStringKey.font as NSCopying)
        let strSize = self.boundingRect(with: size, options: .usesLineFragmentOrigin, attributes: dic as? [NSAttributedStringKey : Any], context:nil).size
        return strSize
    }
}

上面的这个extension直接放到上面封装的view里面就好了，也不要去创建新的文件

3.现在基本上做的封装已经完成，接下来就是调用

/// 我这里是测试下，我在viewController里面写的直接附上所有调用代码
import UIKit

class ViewController: UIViewController {

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

        let rect = CGRect(x: 0, y: 100, width: UIScreen.main.bounds.size.width, height: 0)
        let arr = ["把第一个变长点","测试下第二个","看来真的要在简书上面写点东西了","测试2","我先走变长点试试1","测试2","测试1","测试2","测试1"]
        let v = QYPAdaptiveButton.creat(frame: rect, titleArr: arr)
        v.delegate = self
        self.view.addSubview(v)
    }
}
/// 遵守协议，实现代理方法
extension ViewController:QYPAdaptiveButtonDelegate{
    func searchHistory(index: Int) {
        print(index)
    }
}