UIStoryboardSegue：顶视图没有向下滑动答案

【问题标题】：UIStoryboardSegue: top view is not sliding downUIStoryboardSegue：顶视图没有向下滑动
【发布时间】：2015-08-04 08:20:59
【问题描述】：

我有以下 swift 代码，我想要实现的是从顶部滑落的 segue。我希望 secondVCView 位于 firstVCView 下方，并且希望 firstVCView 滑出显示 secondVCView。

目前没有动画，只是闪烁到第二个VCView。

非常感谢

import UIKit

class TopToBottomSegue: UIStoryboardSegue {

override func perform() {

    // Assign the source and destination views to local variables.
    var firstVCView = self.sourceViewController.view as UIView!
    var secondVCView = self.destinationViewController.view as UIView!

    // Get the screen width and height.
    let screenWidth = UIScreen.mainScreen().bounds.size.width
    let screenHeight = UIScreen.mainScreen().bounds.size.height

    // Specify the initial position of the destination view.
    secondVCView.frame = CGRectMake(0, 0, screenWidth, screenHeight)

    // Access the app's key window and insert the destination view below the current (source) one.
    let window = UIApplication.sharedApplication().keyWindow
    window?.insertSubview(secondVCView, belowSubview: firstVCView)

    // Animate the transition.
    UIView.animateWithDuration(0.4, animations: { () -> Void in

        firstVCView.frame = CGRectOffset(firstVCView.frame, 0.0, screenHeight)
        //secondVCView.frame = CGRectOffset(secondVCView.frame, -screenWidth, 0.0)

        }) { (Finished) -> Void in
            self.sourceViewController.presentViewController(self.destinationViewController as! UIViewController,
                animated: false,
                completion: nil)
    }

  }
}

【问题讨论】：

标签： ios iphone swift uistoryboardsegue

【解决方案1】：

据我所知，您需要在 animateWithduration 块中调用 layoutIfNeed 才能获得流畅的动画。

问候

【讨论】：

【解决方案2】：

我不确定这是否是正确的方法，但我设法通过插入两个视图使其工作。

import UIKit

class TopToBottomSegue: UIStoryboardSegue {

override func perform() {
    // Assign the source and destination views to local variables.
    let firstVCView = self.sourceViewController.view as UIView!
    let secondVCView = self.destinationViewController.view as UIView!

    // Get the screen width, height and status bar height.
    let screenWidth = UIScreen.mainScreen().bounds.size.width
    let screenHeight = UIScreen.mainScreen().bounds.size.height
    let statusBarHeight = self.statusBarHeight()

    // Specify the initial position of both views.
    secondVCView.frame = CGRectMake(0.0, 0.0, screenWidth, screenHeight)
    firstVCView.frame = CGRectMake(0.0, statusBarHeight, screenWidth, screenHeight)

    // Access the app's key window and insert the destination view below the current (source) one.
    let window = UIApplication.sharedApplication().keyWindow
    window?.insertSubview(firstVCView, aboveSubview: secondVCView)
    window?.insertSubview(secondVCView, belowSubview: firstVCView)

    // Animate the transition.
    UIView.animateWithDuration(0.3, animations: { () -> Void in

        firstVCView.frame = CGRectOffset(firstVCView.frame, 0.0, screenHeight)

        }) { (Finished) -> Void in
            self.sourceViewController.presentViewController(self.destinationViewController as UIViewController,
                animated: false,
                completion: nil)
    }

}
func statusBarHeight() -> CGFloat {
    let statusBarSize = UIApplication.sharedApplication().statusBarFrame.size
    return Swift.min(statusBarSize.width, statusBarSize.height)
}
}

【讨论】：