详细信息披露加载在之前的详细信息披露之上

Question

我有一个带注释的地图视图，每个注释都有一个日期，月份和时间的相应日期。

我正在把这一天推到新的视图控制器，然后使用switch查看它所属的月份的哪一天，然后显示相应的日历图标。我不能把func放在viewDidAppear以外的任何地方，导致短暂的滞后和两次，阻止我使用

for view in self.view.subviews {
    view.removeFromSuperview()
}

所以有两个问题：

• 如何在viewDidAppear之前调用dayCalendar函数（我试图放置代码的任何地方，它返回nil）
• 如何防止我的detailDisclosures显示在彼此之上？

这是负责显示图像的代码：

override func viewDidAppear(animated: Bool) {
    dayCalendar()
}

func dayCalendar() {

    switch day {
    case 1:
        let calendarDay = "Calendar 1-50.png"
        let calendarDayImage = UIImage(named: calendarDay)
        let calendarDayImageView = UIImageView(image: calendarDayImage!)
        calendarDayImageView.frame = CGRect(x: 25 , y: 350, width: 50, height: 50)
        self.view.addSubview(calendarDayImageView)
    case 8:
        let calendarDay = "Calendar 8-50.png"
        let calendarDayImage = UIImage(named: calendarDay)
        let calendarDayImageView = UIImageView(image: calendarDayImage!)
        calendarDayImageView.frame = CGRect(x: 25 , y: 350, width: 50, height: 50)
        self.view.addSubview(calendarDayImageView)
    case 11:
        let calendarDay = "Calendar 11-50.png"
        let calendarDayImage = UIImage(named: calendarDay)
        let calendarDayImageView = UIImageView(image: calendarDayImage!)
        calendarDayImageView.frame = CGRect(x: 25 , y: 350, width: 50, height: 50)
        self.view.addSubview(calendarDayImageView)

    case 12:
        blahh blahh blahh all the way down

    case 31:
        let calendarDay = "Calendar 30-50.png"
        let calendarDayImage = UIImage(named: calendarDay)
        let calendarDayImageView = UIImageView(image: calendarDayImage!)
        calendarDayImageView.frame = CGRect(x: 25 , y: 350, width: 50, height: 50)
        self.view.addSubview(calendarDayImageView)
    default:
        println("Default")
        break
    }

}

Answer 1

首先：你为什么要切换？据我所知，代码可以简化为

func dayCalendar() {
    if day < 1 || day > 31 {
        return 
    }
    let calendarDay = "Calendar \(day)-50.png"
    let calendarDayImage = UIImage(named: calendarDay)
    let calendarDayImageView = UIImageView(image: calendarDayImage!)
    calendarDayImageView.frame = CGRect(x: 25 , y: 350, width: 50, height: 50)
    self.view.addSubview(calendarDayImageView)
}

您可能希望将呼叫转移到viewWillAppear。

要修复细节闭包的重叠，您有两个选择：

• 每次显示新的一天时删除添加的calendarDayImageView。

或（更好）

• 重新使用已添加的图像视图（如果它已经存在（可能想要创建一个惰性变量）并只更改它正在显示的图像。

您可以通过以下方式实现后者：

// add this variable to your class
lazy var calendarDayImageView: UIImageView = {
    [unowned self] in
    let imageV = UIImageView(frame: CGRect(x: 25 , y: 350, width: 50, height: 50))
    self.view.addSubview(imageV)
    return imageV
}()

// change the dayCalender to make use of the newly added variable
func dayCalendar() {
    if day < 1 || day > 31 {
        return 
    }
    let calendarDay = "Calendar \(day)-50.png"
    let calendarDayImage = UIImage(named: calendarDay)
    calendarDayImageView.image = calendarDayImage
}

或者你可以在viewDidLoad中移动视图的初始化，并再次dayCalender设置实际图像 - 但我喜欢懒惰变量;）