Ios 如何确保在animateWithDuration（）中调用completion

我有一个在UICollectionView之间切换的功能：

func toggleCollectionView(target: NSObject, targetName:String){
    self.view.userInteractionEnabled = false
    if let tempTarget = target as? UICollectionView {
        //if selected item is same as active one, won't do anything
        if(targetName != activeToolbarName){

            tempTarget.hidden = false
            tempTarget.frame.origin.y = screenSize.height
            UIView.animateWithDuration(0.4, delay: 0.0, options: .CurveEaseOut, animations: {
                if let tempActiveToolbar  = self.activeToolbar as? UICollectionView {
                    tempActiveToolbar.frame.origin.y = self.screenSize.height
                }

                tempTarget.frame.origin.y = self.screenSize.height - tempTarget.frame.height - self.selectorsContainer.frame.height
                }, completion: { finished in
                    if let tempActiveToolbar  = self.activeToolbar as? UICollectionView {
                        tempActiveToolbar.hidden = true
                        self.activeToolbar = target
                        self.activeToolbarName = targetName
                        self.view.userInteractionEnabled = true

                    }

            })
        }

    }

}

它由屏幕上的几个按钮触发，如下所示：

@IBAction func showFontsTool(sender: UIBarButtonItem) {
   toggleCollectionView(fontsCV, targetName:"fontsCV")
}

如果用户快速点击按钮，

completion

块有时不会被调用，也不会启用

self.view.userInteractionEnabled

。如何确保启动动画后始终调用

completion

块

更新

固定功能，工作良好：

func toggleCollectionView(target: NSObject, targetName:String){

    if let tempTarget = target as? UICollectionView {
        //if selected item is same as active one, won't do anything
        if(targetName != activeToolbarName){
            tempTarget.hidden = false
            tempTarget.frame.origin.y = screenSize.height

            if (runningAnimation == false){
                runningAnimation = true
                self.activeToolbarName = targetName
                UIView.animateWithDuration(0.4, delay: 0.0, options: .CurveEaseOut, animations: {
                    if let tempActiveToolbar  = self.activeToolbar as? UICollectionView {
                        tempActiveToolbar.frame.origin.y = self.screenSize.height
                    }

                    tempTarget.frame.origin.y = self.screenSize.height - tempTarget.frame.height - self.selectorsContainer.frame.height
                    }, completion: { finished in
                        if let tempActiveToolbar  = self.activeToolbar as? UICollectionView {
                            tempActiveToolbar.hidden = true
                            self.activeToolbar = target
                            self.runningAnimation = false                            }
                })
            }

        }

    }

}

这是一个解决办法：

创建一个布尔变量

animationTriggering

，当按下按钮时，该变量将自身设置为true。此变量可作为您检查的标志；如果为真，请不要再次执行UIView动画。您将仅在UIView动画处于false状态时执行它

UIView动画完成后，将其设置回false，以便下次再次触发

我猜问题是由多线程问题造成的。我以前也遇到过这种情况，但我真的没有信心说我知道问题出在哪里

---

如果我可以冒昧猜测一下，那就是UIView动画有一个内部异步线程，如果您发送请求太快，它会相互干扰。

首先，您必须声明一个全局Bool变量

var isAnimating:BOOL = False

现在在按钮操作中

@IBAction func showFontsTool(sender: UIBarButtonItem) {
   if(!isAnimating) //if animation is not happening then call the method
   {
     toggleCollectionView(fontsCV, targetName:"fontsCV")
   }
   else  //if animation is happening then return
   {
     return;
   }

}

现在，在动画方法（即

func-toggleCollectionView

）中，设置

isAnimating

变量的值，如下所示：-

func toggleCollectionView(target: NSObject, targetName:String){
    isAnimating=True   //notify animation has started, so that this method don't get fire on button click
    self.view.userInteractionEnabled = false
    if let tempTarget = target as? UICollectionView {
        //if selected item is same as active one, won't do anything
        if(targetName != activeToolbarName){

            tempTarget.hidden = false
            tempTarget.frame.origin.y = screenSize.height
            UIView.animateWithDuration(0.4, delay: 0.0, options: .CurveEaseOut, animations: {
                if let tempActiveToolbar  = self.activeToolbar as? UICollectionView {
                    tempActiveToolbar.frame.origin.y = self.screenSize.height
                }

                tempTarget.frame.origin.y = self.screenSize.height - tempTarget.frame.height - self.selectorsContainer.frame.height
                }, completion: { finished in
                    if let tempActiveToolbar  = self.activeToolbar as? UICollectionView {
                        tempActiveToolbar.hidden = true
                        self.activeToolbar = target
                        self.activeToolbarName = targetName
                        self.view.userInteractionEnabled = true
                        isAnimating=False //now set bool value  on this completion handler to false so that this method can get fired again. 

                    }

            })
        }

    }

}

---

忘了提了。我建议您将userInteraction enabled设置为false，前提是您确定要将其交换回true。。。你应该把它放在

ui视图的前面。设置动画
呼叫。谢谢你的回答。