下面在我的代码中,我试图使用Facebook SDK获取我的朋友列表并在另一个视图控制器上显示它们。我在函数createFriendsInfo(data : NSArray)
中调用函数loginViewShowingLoggedInUser
。正在调用该函数,数据正在数组中填充。
问题是在createFriendsInfo
中的循环完成填充数组中的数据后,控件直接进入视图控制器。相反,它应该首先在函数循环之后完成执行语句,然后控件应该返回loginViewShowingLoggedInUser
,performSegueWithIdentifier:
应该执行。
我是Swift的新手,我需要一些帮助来理解代码中的控制流程。
import Foundation
import UIKit
class FBViewController : UIViewController, FBLoginViewDelegate {
@IBOutlet var fbLogin: FBLoginView!
var friendNames : [String] = []
var friendPics : [UIImage] = []
override func viewDidLoad() {
super.viewDidLoad()
//var fbl: FBLoginView = FBLoginView() //create login button on UIController
//self.view.addSubview(fbl)
// Do any additional setup after loading the view, typically from a nib.
self.fbLogin.delegate = self
self.fbLogin.readPermissions = ["public_profile", "email", "user_friends"]
}
func createFriendsInfo(data : NSArray)
{
println("Start Create")
for i in 0...data.count {
let valueDict : NSDictionary = data[i] as NSDictionary
let userID = valueDict.objectForKey("id") as String
self.friendNames.append(valueDict.objectForKey("name") as String)
let id = valueDict.objectForKey("name") as String
var url = NSURL (string : "http://graph.facebook.com/\(userID)/picture?type=large")
let urlRequest = NSURLRequest(URL: url!)
let session = NSURLSession.sharedSession()
var response: AutoreleasingUnsafeMutablePointer<NSURLResponse?>=nil
var error: NSErrorPointer = nil
if let ImageData : NSData = NSURLConnection.sendSynchronousRequest(urlRequest, returningResponse: response, error:nil)?
{
var image = UIImage( data : ImageData)
self.friendPics.append(image!)
println("Image Appended")
}
}
println("Create Friends Info \(self.friendNames.count) \(self.friendPics.count) ")
}
// Facebook Delegate Methods
func loginViewShowingLoggedInUser(loginView : FBLoginView!) {
println("Start Fetched")
var friendsRequest : FBRequest = FBRequest.requestForMyFriends()
friendsRequest.startWithCompletionHandler{(connection:FBRequestConnection!, result:AnyObject!, error:NSError!) -> Void in
var resultdict = result as NSDictionary
println("Result Dict: \(resultdict)")
var Data : NSArray = resultdict.objectForKey("data") as NSArray
self.createFriendsInfo(Data)
println("Perform \(self.friendNames.count) \(self.friendPics.count) ")
self.performSegueWithIdentifier("toFriendList", sender: self)
println("Perform \(self.friendNames.count) \(self.friendPics.count) ")
//
}
//self.performSegueWithIdentifier("toFriendList", sender: self)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func loginViewFetchedUserInfo(loginView : FBLoginView!, user: FBGraphUser) {
}
func loginViewShowingLoggedOutUser(loginView : FBLoginView!) {
println("User Logged Out")
self.friendNames = []
self.friendPics = []
println("Logout \(self.friendNames.count) \(self.friendPics.count) ")
}
func loginView(loginView : FBLoginView!, handleError:NSError) {
println("Error: \(handleError.localizedDescription)")
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if((segue.identifier == "toFriendList" ) && (self.friendNames.count > 0))
{
var fl : friendList = segue.destinationViewController as friendList
println("Prepare \(self.friendNames.count) \(self.friendPics.count) ")
fl.name1 = self.friendNames
fl.profilepics1 = self.friendPics
}
}
}
答案 0 :(得分:1)
for
中的createFriendsInfo
循环上限错误;通常是0..<data.count
。实际上,
for i in 0...data.count {
let valueDict : NSDictionary = data[i] as NSDictionary
// ...
<{1>}时将“失败”。
但是,对于控制流,i == data.count
完成处理程序最肯定不会在主队列上运行。这意味着friendsRequest
将“迷失”。将您的代码更改为:
performSegueWithIdentifier
必须在主队列上执行所有UI操作。
请注意,您可能需要在func loginViewShowingLoggedInUser(loginView : FBLoginView!) {
println("Start Fetched")
var friendsRequest : FBRequest = FBRequest.requestForMyFriends()
friendsRequest.startWithCompletionHandler{
(connection:FBRequestConnection!, result:AnyObject!, error:NSError!) -> Void in
var resultdict = result as NSDictionary
println("Result Dict: \(resultdict)")
var Data : NSArray = resultdict.objectForKey("data") as NSArray
self.createFriendsInfo(Data)
println("Perform \(self.friendNames.count) \(self.friendPics.count) ")
dispatch_async(dispatch_get_main_queue()) {
self.performSegueWithIdentifier("toFriendList", sender: self)
println("Perform \(self.friendNames.count) \(self.friendPics.count) ")
//
}
}
}
的闭包中将self
声明为unowned
(我忘记了当前的Swift状态)