堆棧內存溢出
  簡體   English   中英

我為什么從另一個視圖控制器調用時我的表視圖為nil？

[英]iWhy my table view is nil when i called from another view controller?

 原文  2015-04-06 11:15:19  8   1    ios/ uitableview/ swift/ uilabel/ iboutlet

問題描述

我試圖在用戶注銷時通過將表視圖中的標簽設置為“僅成員”從左菜單（滑出）重新加載表視圖控制器。因此，我將其稱為refreshAuctionLatestViewController.viewWillAppear（true）。但是，該表認為將在該方法中重新加載的視圖為nil。有幫助嗎？

這是我的幻燈片菜單控制器（SlideMenu） 

import UIKit


class LeftMenuViewController: UIViewController ,UITableViewDataSource, UITableViewDelegate{

@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var userEmail: UIButton!
@IBOutlet weak var btnLogOut: UIButton!
var refreshActionLatestController:AuctionLatestViewController!

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(true)

    let isLoggedIn = TegKeychain.get("isLoginIn")
    let userEmail = TegKeychain.get("userEmail_keyChain")
    if (isLoggedIn != "1") {
        self.btnLogOut.enabled = false
        self.btnLogOut.hidden = true
        self.userEmail.enabled = true
    }else if userEmail != nil{
        self.userEmail.titleLabel?.text = userEmail
        self.userEmail.enabled = false
        self.btnLogOut.enabled = true
        self.btnLogOut.hidden = false
    }
}
@IBAction func logoutTapped(sender : UIButton) {

    refreshActionLatestController = AuctionLatestViewController()

    self.slideMenuController()?.closeLeft() //Closing the Slide and show user with alert on main view controller

    let logOutAlertController = UIAlertController(title : "Log Out",message: "Are You Sure You Gonna Log Out?",preferredStyle : .ActionSheet)

    let callAction = UIAlertAction(title: "Log Out", style: .Default, handler: {
        action in

        var token:NSString = TegKeychain.get("userToken_keyChain")!
        var email:NSString = TegKeychain.get("userEmail_keyChain")!

        var params : Dictionary <String,String> = ["appid" : token, "email" : email]
        var params2 = self.createStringFromDictionary(params)
        var paramsLength = "\(countElements(params2))"

        var err: NSError?

        NSLog("PostData: %@",params2);

        var url:NSURL = NSURL(string:"http://localhost:8080/xx/xxx/account/logout")!

        var requestBodyData = (params2 as NSString).dataUsingEncoding(NSUTF8StringEncoding)


        var request:NSMutableURLRequest = NSMutableURLRequest(URL: url)
        request.HTTPMethod = "POST"
        request.HTTPBody = requestBodyData
        request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
        request.setValue("application/json", forHTTPHeaderField: "Accept")


        var reponseError: NSError?
        var response: NSURLResponse?

        var urlData: NSData? = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&reponseError)

            if ( urlData != nil ) {
                let res = response as NSHTTPURLResponse!;

                NSLog("Response code: %ld", res.statusCode);

                if (res.statusCode >= 200 && res.statusCode < 300)
                {
                    var responseData:NSString  = NSString(data:urlData!, encoding:NSUTF8StringEncoding)!

                    NSLog("Response ==> %@", responseData);

                    var err: NSError?

                    let jsonData:NSDictionary = NSJSONSerialization.JSONObjectWithData(urlData!, options:NSJSONReadingOptions.MutableContainers , error: &err) as NSDictionary

                    let status:NSString = jsonData.valueForKey("status") as NSString

                    //let error:NSString = jsonData.valueForKey("error") as NSString

                    NSLog("Status:", status);
                    NSLog("Error:", status);

                    if(status == "ok")
                    {
                        NSLog("Log Out SUCCESS");

                        TegKeychain.delete("userEmail_keyChain")
                        TegKeychain.delete("isLoginIn")
                        TegKeychain.delete("userToken_keyChain")
                        TegKeychain.delete("userName_keyChain")



    self.refreshActionLatestController?.viewWillAppear(true) //doesn't work,keep showing me nil at carTableView
    //self.refreshActionLatestController?.searchForResults(true) 
    // I already initialize that main view controlller,but table view of that main view still showing nil when i created output of it.

                        self.userEmail.titleLabel?.text = "Sign In"
                        self.userEmail.enabled = true
                        self.btnLogOut.enabled = false
                        self.btnLogOut.hidden = true
                    }
                    else if status == "error"{

                        var alertView:UIAlertView = UIAlertView()
                        alertView.title = "Log Out Failed!"
                        alertView.message = "Connection Failed"
                        alertView.delegate = self
                        alertView.addButtonWithTitle("OK")
                        alertView.show()
                    }
                } else {
                    TegKeychain.delete("userEmail_keyChain")
                    TegKeychain.delete("isLoginIn")
                    TegKeychain.delete("userToken_keyChain")
                    TegKeychain.delete("userName_keyChain")

                    self.userEmail.titleLabel?.text = "Sign In"
                    self.btnLogOut.enabled = false
                    self.btnLogOut.hidden = true
                    self.dismissViewControllerAnimated(true, completion: nil)

                    var alertView:UIAlertView = UIAlertView()
                    alertView.title = "Already Log Out!"
                    alertView.message = "You account has been already log out"
                    alertView.delegate = self
                    alertView.addButtonWithTitle("OK")
                    alertView.show()
                }
            }
            else {
                var alertView:UIAlertView = UIAlertView()
                alertView.title = "Log Out Failed!"
                alertView.message = "Connection Failed"
                alertView.delegate = self
                alertView.addButtonWithTitle("OK")
                alertView.show()
            }
        }
    )
    logOutAlertController.addAction(callAction)

    let defaultAction = UIAlertAction(title: "Cancel", style: .Default, handler: nil)
    logOutAlertController.addAction(defaultAction)
    presentViewController(logOutAlertController, animated: true, completion: nil)
}

func createStringFromDictionary(dict: Dictionary<String,String>) -> String {
    var params = String()
    for (key, value) in dict {
        params += "&" + key + "=" + value
    }
    return params
}
}

這是我的主視圖控制器[這些是拍賣車的列表] 

import UIKit

class AuctionLatestViewController: UIViewController,UITableViewDataSource,UITableViewDelegate,AuctionAPIProtocol{

@IBOutlet var carTableView : UITableView?
@IBOutlet var carTableIndicator : UIActivityIndicatorView?
@IBOutlet var retryButton:UIButton?

var latestCars = [AuctionModel]()
var api : AuctionAPI?
var imageCache = [String : UIImage]()
var token : String = " "
var lotId : String = " "
var page : String = " "

override func viewDidLoad() {
    println("Auction Latest : viewDidLoad")
    super.viewDidLoad()
    self.setNavigationBarItem()
    self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)

    carTableView?.hidden = true
    retryButton?.hidden=true
    carTableIndicator?.center
    carTableIndicator?.startAnimating()

    if TegKeychain.get("userToken_keyChain") == nil{
        token = "null"
    }
    else{
        token = TegKeychain.get("userToken_keyChain")!
    }
    lotId = "1"
    page = "1"

    api = AuctionAPI(delegate: self)
    api!.searchAuctionLatestFor(token,lotId: lotId,page: page)
}

override func viewWillAppear(animated: Bool) {
    println("Auction Latest : ViewWillAppear")

    super.viewWillAppear(animated)
    self.setNavigationBarItem()
    if TegKeychain.get("userToken_keyChain") == nil{
        token = "null"
    }
    else{
        token = TegKeychain.get("userToken_keyChain")!
    }
    lotId = "1"
    page = "1"
    api = AuctionAPI(delegate: self)
    api!.searchAuctionLatestFor(token,lotId: lotId,page: page)
}

//Table View DataSource and Delegate

// Implementing the json results from api.
func didReceiveAPIResults(results: NSDictionary) {
    var resultsArr: NSArray = results["body"] as NSArray //fix
    dispatch_async(dispatch_get_main_queue(), {
        self.latestCars = AuctionModel.latestWithJSON(resultsArr)
        println(self.carTableView)

        self.carTableView?.reloadData() // I reload the table view
        println(self.carTableView)// which return nil when i called from Slide Menu Controller.But return data,if the main view controller called.

        self.retryButton?.hidden=true
        self.retryButton?.enabled=false
        self.carTableIndicator?.stopAnimating()
        self.carTableView?.hidden = false
    })
}

// The function that i call from slide menu when log out
func searchForResults(search:Bool){
    println("Search Again")

    retryButton?.enabled=false
    retryButton?.hidden=true
    carTableIndicator?.startAnimating()
    api = AuctionAPI(delegate: self)

    if TegKeychain.get("userToken_keyChain") == nil{
        token = "null"
    }
    else{
        token = TegKeychain.get("userToken_keyChain")!
    }
    lotId = "1"
    page = "1"

    api = AuctionAPI(delegate: self)
    api!.searchAuctionLatestFor(token,lotId: lotId,page: page)
    //it will go to didReceiveAPIResults() method
}

這是我的控制台輸出，您將在下面看到nil。 

PostData: &appid=9cdcf896d1f54c3c11b0d4839ce26775
Response ==> {"status":"authorized"}
Status:
Already Sign In
Auction Latest : viewDidLoad
Auction Latest : ViewWillAppear
task completed
Optional(<UITableView: 0x7faa9c852000; framet a=s k( 0c o0m;p l3e2t0e d5
68); clipsToBounds = YES; hidden = YES; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x7faa9bda1f00>; layer = <CALayer: 0x7faa9bd9e750>; contentOffset: {0, -64}; contentSize: {320, 0}>)
Optional(<UITableView: 0x7faa9c852000; frame = (0 0; 320 568); clipsToBounds = YES; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x7faa9bda1f00>; layer = <CALayer: 0x7faa9bd9e750>; contentOffset: {0, -64}; contentSize: {320, 91}>)
Auction Latest : ViewWillAppear
task completed
Optional(<UITableView: 0x7faa9c852000; frame = (0 0; 320 568); clipsToBounds = YES; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x7faa9bda1f00>; layer = <CALayer: 0x7faa9bd9e750>; contentOffset: {0, -64}; contentSize: {320, 91}>)
Auction Latest : ViewWillAppear
task completed
Optional(<UITableView: 0x7faa9c852000; frame = (0 0; 320 568); clipsToBounds = YES; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x7faa9bda1f00>; layer = <CALayer: 0x7faa9bd9e750>; contentOffset: {0, -64}; contentSize: {320, 91}>)
PostData: &email=example.test@gmail.com&appid=9cdcf896d1f54c3c11b0d4839ce26775
Response code: 200
Response ==> {"status":"ok"}
Status:
Error:
Log Out SUCCESS
Auction Latest : ViewWillAppear
task completed
nil

有任何想法嗎？有任何建議嗎？

1 個解決方案

解決方案1
 0  2015-04-06 11:36:02

要更新該菜單，您必須調用已采用該表格視圖的該類的方法，並為此做一件事，將該類的對象創建到要更新的其他類中，然后通過該方法進行調用該類的..

[sliderpage viewWillAppear：YES];

這里silderpage是菜單頁面的對象。

希望對您有幫助。...

暫無
暫無

聲明:本站的技術帖子網頁，遵循CC BY-SA 4.0協議，如果您需要轉載，請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.

相關問題 從另一個視圖控制器 swift 重新加載表視圖時發現 Nil 錯誤 當嘗試從表視圖轉到視圖控制器時，我收到此錯誤：Unexpectedly found nil while unwrapping 在prepareForSeque時，委托不是nil，但在Navigation Table View中調用時，委托nil 使用Segue從先前的View Controller傳遞到另一個View Controller時，數據變為Nil 如何將信息從一個視圖控制器中的表視圖單元傳遞到另一視圖控制器？ 訪問另一個視圖控制器的功能時意外發現nil iOS-如何在我的應用啟動時將另一個視圖控制器設置為我的初始視圖控制器？ 從另一個視圖控制器訪問元素顯示為nil 使用標簽欄從另一個視圖返回時不會調用視圖控制器 從一個視圖控制器轉換到另一個視圖控制器時，視圖方法的調用順序是什么？
相關標簽
 
粵ICP備18138465號  © 2020-2024 STACKOOM.COM