Question

我在下面有以下课程。我们的想法是使用自定义进度窗口视图控制器来处理各种不同事件的进度。问题是因为这是一个类，而不是一个视图控制器它是自己的，我不确定如何在从故事板中实例化后实际显示progressWindow？

我该怎么做？目前我收到一个错误，应用程序试图自己呈现模型视图控制器。

import Foundation
import UIKit

class StatusProgress{
    static var cancelCode = {}
    static var runCode = {}
    static var theProgressWindowController = ProgressWindowViewController()
    static var returningViewControllerIdentifier = ""
    static let storyboard = UIStoryboard(name: "Main", bundle: nil)

    static func run(){
        // This will run in parralel but on main queue.  Has to be on this Queue because it might involve UI
        dispatch_async(dispatch_get_main_queue(), {
            // Update the UI on the main thread.
            StatusProgress.runCode()
        });

    }

    static func cancel(){
        dispatch_async(dispatch_get_main_queue(), {
            StatusProgress.cancelCode()
            dispatch_sync(dispatch_get_main_queue(),{
                let storyboard = UIStoryboard(name: "Main", bundle: nil)
                let vc = storyboard.instantiateViewControllerWithIdentifier(returningViewControllerIdentifier)
                vc.presentViewController(vc, animated: true, completion: nil)
            })
        });
    }

    static func show(){
        dispatch_async(dispatch_get_main_queue(),{
            theProgressWindowController = self.storyboard.instantiateViewControllerWithIdentifier("progressWindow") as! ProgressWindowViewController
            theProgressWindowController.presentViewController(theProgressWindowController, animated: true, completion: nil) //use own instance to show it's self? (throws error! application tried to present modal view controller on itself. Presenting controller is <Inventory_Counter.ProgressWindowViewController: 0x1466ea390>.')
        })
    }
}

我的问题基本上我需要替换此代码行。

theProgressWindowController.presentViewController(theProgressWindowController, animated: true, completion: nil)

我忘记在这里提到的是在另一个视图控制器中运行它的代码。

SyncViewController.swift

import UIKit

class SyncViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func yesSyncButtonAction(sender: UIButton) {
        StatusProgress.returningViewControllerIdentifier = "syncWindow"
        StatusProgress.runCode = {
            print("run code test")
        }
        StatusProgress.cancelCode = {
            print("cancel code test")
        }
        StatusProgress.show()
    }

    @IBAction func noSyncActionButton(sender: UIButton) {
        tabBarController?.selectedIndex = 1 //assume back to inventory section
    }

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        // Get the new view controller using segue.destinationViewController.
        // Pass the selected object to the new view controller.
    }
    */

}

Answer 1

最大的问题是你的StatusProgress类正在实例化并显示一个视图控制器。视图控制器应该实例化并显示其他视图控制器，模型对象不应该。因此，您需要将用于呈现新视图控制器的逻辑移到您SyncViewController中。然后使用委托与SyncViewController进行通信以完成同步。

protocol StatusProgressDelegate {
  func statusProgress(status: StatusProgress, shouldShow: Bool)
  func statusProgress(status: StatusProgress, shouldCancel: Bool)
}

您的StatusProgress对象将拥有一个符合该协议的委托，并在其show和cancel方法中调用该委托。这意味着您需要创建静态函数实例方法，并为该类编写初始化程序，以便您可以实例化它。

Answer 2

如果视图生命周期事件对您来说不是很重要，您可以只添加进度控制器的视图以查看当前控制器。或者如果你在show()函数中提供UIView参数，它会更好。

static func show(attachToView: UIView ){
        dispatch_async(dispatch_get_main_queue(),{
            theProgressWindowController = self.storyboard.instantiateViewControllerWithIdentifier("progressWindow") as! ProgressWindowViewController
             attachToView.addSubview(theProgressWindowController.view)
        })
    }

毕竟，您最好从superview中删除进度视图

   static func cancel(){
            dispatch_async(dispatch_get_main_queue(),{
                theProgressWindowController = self.storyboard.instantiateViewControllerWithIdentifier("progressWindow") as! ProgressWindowViewController
                 theProgressWindowController.view.removeFromSuperview()
            })
        }

如何查看控制器是否呈现自身？

2 个答案: