ios - removeFromSuperview() 耗时太长

Question

在使用 imagePickerController 选择图像后，我尝试使用 Core Data 从我的 ViewController.swift 中保存一个对象。我在保存时显示带有微调器的 View (DynamicView)。对象在 1 或 2 秒内保存，但 DynamicView 需要 7 或 8 秒才能从 superView 中删除。

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]){
    dismissViewControllerAnimated(true, completion: nil)
    picture = info[UIImagePickerControllerOriginalImage] as? UIImage
    view.addSubview(DynamicView)
    var newImageData = UIImageJPEGRepresentation(picture, 1)
    objectToSave?.photo = newImageData
    progressBarDisplayer("test", true)
    dispatch_async(dispatch_get_global_queue(
        Int(QOS_CLASS_USER_INTERACTIVE.value), 0)) {
            self.save()
    }
}

func save() {
    var error : NSError?
    if(!managedObjectContext!.save(&error) ) {
        println(error?.localizedDescription)
    }else{
        println("No error, saved")
        self.DynamicView.removeFromSuperview()


    }
    NSNotificationCenter.defaultCenter().postNotificationName("load", object: nil)
} 

Answer 1

从主线程调用 removeFromSuperview() 以确保您的 UI 是同步的:

func save() {
    var error : NSError?
    if(!managedObjectContext!.save(&error) ) {
        println(error?.localizedDescription)
    }else{
        println("No error, saved")
        dispatch_async(dispatch_get_main_queue(),{            
            self.DynamicView.removeFromSuperview()
        }


    }
    NSNotificationCenter.defaultCenter().postNotificationName("load", object: nil)
}