swift新手进阶30天一 自定义上图片下文字的UIButton的几种方式

目前很多app首页功能区都类似工具栏上图标加下文字的方式来自定义按钮。当然，我们也可以用两个控件实现，但是，提升不了我们的逼格。接下来就介绍几种自定义这种上图标下文字的按钮的几种方式。先上图。
![首页自定义按钮.png](https://img-blog.youkuaiyun.com/20170629213116116?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvYTExMzc2MTE4MjQ=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)

一、利用属性文本NSAttributedString来生成图片文本上下排列的按钮

1.复写NSAttributedString方法

// MARK: -使用图像和文本生成上下排列的属性文本
extension NSAttributedString {

    //将图片属性以及文字属性用方法名传入
    class func imageTextInit(image: UIImage, imageW: CGFloat, imageH: CGFloat, labelTitle: String, fontSize: CGFloat, titleColor: UIColor, labelSpacing: CGFloat) -> NSAttributedString{

        //1.将图片转换成属性文本
        let attachment = NSTextAttachment()
        attachment.image = image
        attachment.bounds = CGRectMake(0, 0, imageW, imageH)
        let imageText = NSAttributedString(attachment: attachment)

        //2.将标题转化为属性文本
        let titleDict = [NSFontAttributeName: UIFont.systemFontOfSize(fontSize), NSForegroundColorAttributeName: titleColor]
        let text = NSAttributedString(string: labelTitle, attributes: titleDict)

        //3.换行文本可以让label长度不够时自动换行
        let spaceDict = [NSFontAttributeName:UIFont.systemFontOfSize(labelSpacing)]
        let lineText = NSAttributedString(string: "\n\n", attributes: spaceDict)


        //4.合并属性文字
        let mutableAttr = NSMutableAttributedString(attributedString: imageText)
        mutableAttr.appendAttributedString(lineText)
        mutableAttr.appendAttributedString(text)

        //5.将属性文本返回
        return mutableAttr.copy() as! NSAttributedString
    }

}

2.写好了属性文本，接下来就把添加进UIButton中去

class func YWHomeListButton(imageName: String, titleName: String!) -> UIButton {

        //创建按钮类型为Custom
        let btn = UIButton(type: .Custom)
        //获取我们刚得到的属性文本，直接是NSAttributedString的子方法了
        let attrStr = NSAttributedString.imageTextInit(UIImage(named: imageName)!, imageW: SCREEN_WIDTH/8*3/2, imageH: SCREEN_WIDTH/8, labelTitle: titleName, fontSize: 12, titleColor: UIColor.lightGrayColor(), labelSpacing: 4)
        //设置按钮基本属性
        btn.titleLabel?.textAlignment = .Center
        btn.titleLabel?.numberOfLines = 0
        btn.setAttributedTitle(attrStr, forState: .Normal)
        return btn

    }

3.接下来就可以用我们刚自己定义的按钮了

let btn1 = UIButton.YWHomeListButton("homeList1", titleName: "抽奖")
let btn2 = UIButton.YWHomeListButton("homeList2", titleName: "领红包")
let btn3 = UIButton.YWHomeListButton("homeList3", titleName: "蜂抱团")
let btn4 = UIButton.YWHomeListButton("homeList4", titleName: "一元购")

二、修改UIButton系统的titleRectForContentRect和imageRectForContentRect方法来改变文字和图片的相对位置

1.通过计算得出我们需要的上下排列的效果

import UIKit

class YWButton: UIButton {

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

        commonInit()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    //设置按钮的基本属性
    func commonInit() {
        self.titleLabel?.textAlignment = .Center
        self.imageView?.contentMode = .ScaleAspectFit
        self.titleLabel?.font = UIFont.systemFontOfSize(12)
    }

    //调整系统UIButton的文字的位置
    override func titleRectForContentRect(contentRect: CGRect) -> CGRect {
        let titleX = 0
        let titleY = contentRect.size.height * 0.35
        let titleW = contentRect.size.width
        let titleH = contentRect.size.height - titleY
        return CGRectMake(CGFloat(titleX), titleY, titleW, titleH)
    }

    //调整系统UIButton的图片的位置
    override func imageRectForContentRect(contentRect: CGRect) -> CGRect {
        let imageW = CGRectGetWidth(contentRect)
        let imageH = contentRect.size.height * 0.4
        return CGRectMake(0, 5, imageW, imageH)
    }
}

2.接下来就可以直接应用我们自己的控件了

        let basketBtn = YWButton(type: .Custom)
        basketBtn.setTitleColor(themeColor, forState: .Normal)
        basketBtn.setTitle("购物车", forState: .Normal)
        basketBtn.setImage(UIImage(named: "YS_car_sel"), forState: .Normal)
        toolBarView.addSubview(basketBtn)

        let storeBtn = YWButton(type: .Custom)
        storeBtn.setTitleColor(themeColor, forState: .Normal)
        storeBtn.setTitle("店铺", forState: .Normal)
        storeBtn.setImage(UIImage(named: "ysstoreIcon"), forState: .Normal)
        toolBarView.addSubview(storeBtn)

三、修改UIButton的EdgeInset属性来改变文字与图片的相对位置

extension UIButton {

    func layoutButton(imageTitleSpace: CGFloat) {
        //得到imageView和titleLabel的宽高
        let imageWidth = self.imageView?.frame.size.width
        let imageHeight = self.imageView?.frame.size.height

        var labelWidth: CGFloat! = 0.0
        var labelHeight: CGFloat! = 0.0

        labelWidth = self.titleLabel?.intrinsicContentSize().width
        labelHeight = self.titleLabel?.intrinsicContentSize().height

        //初始化imageEdgeInsets和labelEdgeInsets
        var imageEdgeInsets = UIEdgeInsetsZero
        var labelEdgeInsets = UIEdgeInsetsZero


        //重点： 修改imageEdgeInsets和labelEdgeInsets的相对位置的计算
       imageEdgeInsets = UIEdgeInsetsMake(-labelHeight-imageTitleSpace/2, 0, 0, -labelWidth)
       labelEdgeInsets = UIEdgeInsetsMake(0, -imageWidth!, -imageHeight!-imageTitleSpace/2, 0)
                break;


        self.titleEdgeInsets = labelEdgeInsets
        self.imageEdgeInsets = imageEdgeInsets

    }