无法从上到下显示日期选择器？答案

【问题标题】：Unable to show date picker from top to bottom?无法从上到下显示日期选择器？
【发布时间】：2018-02-19 09:50:49
【问题描述】：

我创建了一个自定义日期选择器。我想从下到上显示它。但它没有显示它是从上到下显示。

这里是代码。

let frame:CGRect = CGRect(x: 0, y: 600, width: self.view.frame.width, height: self.view.frame.height/3)
        self.datePicker = CustomDatePicker.instanceFromNib(frame: frame) as? CustomDatePicker
        self.datePicker?.configureDatePicker()
        datePicker?.customPickerDelegate = self
        UIView.animate(withDuration: 1.5, animations: {

            DILog.print(items: "Updated Y is \(self.view.frame.height - self.view.frame.height/3)")
            let frame:CGRect = CGRect(x: 0, y: 300, width: self.view.frame.width, height: self.view.frame.height/3)
            self.datePicker = CustomDatePicker.instanceFromNib(frame: frame) as? CustomDatePicker

        }, completion: { (value) in

        })
        self.view.addSubview(self.datePicker!)

【问题讨论】：

你怎么能期望 UIView 上的动画还不是子视图？应该关闭
这是简单的一行解决方案从动画块中删除 self.datePicker = Custo... 并直接设置框架，在执行动画之前只需添加子视图

标签： ios swift xcode datepicker

【解决方案1】：

首先必须在动画之前添加动画选择器，其次您不能在动画中再次从笔尖加载选择器

         let frame:CGRect = CGRect(x: 0, y: 600, width: self.view.frame.width, height: self.view.frame.height/3)
         self.datePicker = CustomDatePicker.instanceFromNib(frame: frame) as? CustomDatePicker

        self.datePicker?.configureDatePicker()
        datePicker?.customPickerDelegate = self
        self.view.addSubview(self.datePicker!)
        UIView.animate(withDuration: 1.5, animations: {

            DILog.print(items: "Updated Y is \(self.view.frame.height - self.view.frame.height/3)")

            self.datePicker.frame = CGRect(x: 0, y: 300, width: self.view.frame.width, height: self.view.frame.height/3)

        }, completion: { (value) in

        })

【讨论】：

【解决方案2】：

通过一些很酷的动画，您可以执行以下操作...

 //configure date picker and add it

//animate it in this way
    UIView.animate(withDuration: 1.5, delay: 0, usingSpringWithDamping: 0.5, initialSpringVelocity: 1, options: .curveEaseIn, animations: {

        self.datePicker.frame = CGRect(x: 0, y: 300, width: self.view.frame.width, height: self.view.frame.height/3)

    }) { (isDone) in

    }

【讨论】：

【解决方案3】：

First：在动画之前在父视图中添加 datePicker。除非您这样做，否则它将不可见。
第二：您的选择器的 y 在动画块中不是动态的。它应该是原始 y - 选择器的高度。

整体代码：

let frame:CGRect = CGRect(x: 0, y: 600, width: self.view.frame.width, height: self.view.frame.height/3)
self.datePicker = CustomDatePicker.instanceFromNib(frame: frame) as? CustomDatePicker
self.datePicker?.configureDatePicker()
datePicker?.customPickerDelegate = self
self.view.addSubview(self.datePicker!)
UIView.animate(withDuration: 1.5, animations: {

    DILog.print(items: "Updated Y is \(self.view.frame.height -        self.view.frame.height/3)")
    let frame:CGRect = CGRect(x: 0, y: 600 - self.view.frame.height/3, width: self.view.frame.width, height: self.view.frame.height/3)
    self.datePicker = CustomDatePicker.instanceFromNib(frame: frame) as? CustomDatePicker

        }, completion: { (value) in

        })

【讨论】：