自定义 UIView 不显示任何内容

Question

我创建了一个自定义UIView：

import UIKit

class IndicatorView: UIView {

    var image_view_indicator: UIImageView!
    var label_indicator: UILabel!

    required init(coder decoder: NSCoder) {
        super.init(coder: decoder)!
    }

    init(frame:CGRect, imageName: String, indicatorValue: String)
    {
        super.init(frame: frame)
        self.frame = frame
        image_view_indicator = UIImageView(frame: CGRect(x: 0, y: 0, width: 15, height: 15))
        image_view_indicator.image = UIImage(named: imageName)
        self.addSubview(image_view_indicator)
        self.bringSubviewToFront(image_view_indicator)

        label_indicator = UILabel(frame: CGRect(x: image_view_indicator.frame.size.width + 3, y: 0, width: 25, height: 15))
        label_indicator.text = indicatorValue
        label_indicator.textColor = UIColor.blackColor()
        self.addSubview(label_indicator)
        self.bringSubviewToFront(label_indicator)
    }

}  

这是我从UIViewController 打来的电话：

view_indicator_friends = IndicatorView(frame: view_indicator_friends.frame, imageName: "friend.png", indicatorValue: "20")  

我交叉检查了IBOutlet 连接。他们似乎很好。
但是自定义视图中没有显示任何内容。

Answer 1

当您从Xib 到IBOutlet 连接获取自定义视图时，您的自定义init 将不会被调用，这就是为什么您的image_view_indicator 和label_indicator 没有创建。这就是您的自定义视图无法正确显示的原因。一种解决方案是在awakeFromNib 方法中的init(frame:CGRect, imageName: String, indicatorValue: String) 方法下实现您的代码。

 override func awakeFromNib() {
         let frame =  self.frame
        image_view_indicator = UIImageView(frame: CGRect(x: 0, y: 0, width: 15, height: 15))
        image_view_indicator.image = UIImage(named: imageName)
        self.addSubview(image_view_indicator)
        self.bringSubviewToFront(image_view_indicator)

        label_indicator = UILabel(frame: CGRect(x: image_view_indicator.frame.size.width + 3, y: 0, width: 25, height: 15))
        label_indicator.text = indicatorValue
        label_indicator.textColor = UIColor.blackColor()
        self.addSubview(label_indicator)
        self.bringSubviewToFront(label_indicator)

        }