检索火力存储图像上显示的tableView（SWIFT） [英] Retrieve image from firebase storage to show on tableView (Swift)

问题描述

扩展问题
<一href=\"http://stackoverflow.com/questions/37895171/new-firebase-retrieve-data-and-put-on-the-tableview-swift/37897168?noredirect=1#comment63251725_37897168\">New火力地堡检索数据并换上的tableView（SWIFT）

通过移动火力地堡code到viewDidLoad中，邮政的所有文字部分可以curretly显示。但我还是不能把图像到的tableView。我有检查检索的图像，它是成功的，我想，我从火力地堡检索图像后数组中was't。

By moving the Firebase code to viewDidLoad, all the text part of Post can show curretly. But I still can't put the image to the tableView. I have check the images retrieving and it was success, I suppose that the images I retrieve from Firebase was't in the post array.

这是我的修复code：

this is my fix code:

  import UIKit
  import Firebase
  import FirebaseStorage

class timelineTableViewController: UITableViewController {
var posts = [Post]()
var databaseRef: FIRDatabaseReference!
var storageRef: FIRStorageReference!

override func viewDidLoad() {
    super.viewDidLoad()
    databaseRef = FIRDatabase.database().reference()
    storageRef = FIRStorage.storage().reference()
    let userPostRef = self.databaseRef.child("posts")
    userPostRef.queryOrderedByChild("time").observeEventType(.ChildAdded, withBlock: {(snapshot) in
        if let postAdd  = snapshot.value as? NSDictionary{

            let url = snapshot.value?["postPhoto"] as! String
            let userPhotoUrl = snapshot.value?["userPhoto"] as! String
            let myPost = Post(data: postAdd)

            FIRStorage.storage().referenceForURL(url).dataWithMaxSize(10 * 1024 * 1024, completion: { (data, error) in
                let postPhoto = UIImage(data: data!)

                                    })
            FIRStorage.storage().referenceForURL(userPhotoUrl).dataWithMaxSize(10 * 1024 * 1024, completion: { (data, error) in
                let userPhoto = UIImage(data: data!)
                                })

            self.posts.insert(myPost, atIndex: 0)
            self.tableView.reloadData()

        }




})

}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    // #warning Incomplete implementation, return the number of sections
    return 1
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return posts.count


}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cellIdentifier = "postCell"
    let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath)as! timelineTableViewCell
    //Dispatch the main thread here
    dispatch_async(dispatch_get_main_queue()) {
        cell.usernameLabel.text = self.posts[indexPath.row].username
        cell.postText.text = self.posts[indexPath.row].postText
        cell.timeLabel.text = self.posts[indexPath.row].time
        cell.postPhoto.image = self.posts[indexPath.row].postPhoto
        cell.userPhoto.image = self.posts[indexPath.row].userPhoto


    }
    return cell
   }
   }

和我的岗位结构希望它可以帮助！

And my struct of Post hope it might help!

struct  Post {
var username: String?
var postText: String?
var time: String?
var userPhoto: UIImage?
var postPhoto: UIImage?
var url: String?
var userPhotoUrl:String?
init(data: NSDictionary) {
   username = data["username"] as? String
   postText = data["postText"] as? String
    time = data["time"]as? String
    userPhoto = data["userPhoto"] as? UIImage
    postPhoto = data["postPhoto"] as? UIImage
    url = data["postPhoto"] as? String
    userPhotoUrl = data["userPhoto"] as? String
}

}

希望能得到一些建议！

Hope can get some advice!

推荐答案

只需更改以下方法

func downloadPost(){
    let userPostRef = self.databaseRef.child("posts")

    userPostRef.queryOrderedByChild("time").observeEventType(.ChildAdded, withBlock: {(snapshot) in
        if let postAdd  = snapshot.value as? NSDictionary {
            print("\(snapshot.value)")
            let url = snapshot.value?["postPhoto"] as! String
            let userPhotoUrl = snapshot.value?["userPhoto"] as! String

            var myPost = Post(data: postAdd) //variable change to "var" because going to modify

            let url2 = NSURL(string: url)  //postPhoto URL
            let data = NSData(contentsOfURL: url2!) // this URL convert into Data
            if data != nil {  //Some time Data value will be nil so we need to validate such things 
             myPost.postPhoto = UIImage(data: data!)
            }


            let url3 = NSURL(string: userPhotoUrl)  //userPhoto URL
            let data2 = NSData(contentsOfURL: url3!)  //Convert into data
            if data2 != nil  {  //check the data
            myPost.userPhoto = UIImage(data: data2!)  //store in image
            }




            self.posts.insert(myPost, atIndex: 0)  // then add the "myPost"  Variable
            print(self.posts.count)
        }
        self.tableView.reloadData()  // finally going to load the collection of data in tableview
    })


}

对其采取加载时间大大。因为图像转换并将其存储在mainqueue

its take loading time much. because converting the image and store it in the mainqueue.

另一个途径是存储URL和访问的tableview显示的URL。可以应用异步加载在ImageView的。

another ways is store the URL and access the URL on the tableview display. can apply the async loading in the imageview.

这篇关于检索火力存储图像上显示的tableView（SWIFT）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！