Swift iOS：通过 UISearchBar 查找解析用户并在表格视图中显示结果

Question

我尝试通过 UISearchBar 查找解析用户并在表格视图中显示结果。 当我热搜时，什么也没发生... 我的想法是使用 searchText.text 作为对 PFUser 的查询。

我应该尝试将 searchBar 与搜索显示控制器一起使用吗？ 有什么想法吗？

import UIKit


  class AllFriendsTableViewController: UITableViewController, UISearchBarDelegate,      UISearchDisplayDelegate {
@IBOutlet var SearchDisplay: UISearchDisplayController!



var userList:NSMutableArray = NSMutableArray()


 func searchBarShouldBeginEditing(searchBar: UISearchBar!) -> Bool {
    return true
}

func searchBarShouldEndEditing(searchBar: UISearchBar!) -> Bool {
    return true

}

func searchBar(searchBar: UISearchBar!, textDidChange searchText: String!) {
    loadUser()
}



@IBOutlet var searchText: UISearchBar!



func loadUser () {

    userList.removeAllObjects()
    var findUser:PFQuery = PFUser.query()
    findUser.whereKey("username", equalTo: searchText.text)


    findUser.findObjectsInBackgroundWithBlock { (objects:[AnyObject]!, error:NSError!) -> Void in
        if !(error != nil) {
            // The find succeeded.
            println("succesfull load Users")
            // Do something with the found objects
            for object  in objects  {
                self.userList.addObject(object)
                println("users added to userlist")
            }
            self.tableView.reloadData()
        } else {
            // Log details of the failure
            println("error loadind user ")
            println("error")
        }

    }
}


override func numberOfSectionsInTableView(tableView: UITableView!) -> Int {
    return 1
}

override func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
    if tableView == searchDisplayController.searchResultsTableView {
        return userList.count
    }
    else {
        return 0
    }
}



override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {



    let cell: AllFirendsTableViewCell = self.tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)as AllFirendsTableViewCell


    let users:PFObject = self.userList.objectAtIndex(indexPath!.row) as PFObject


    var findUserName:PFQuery = PFUser.query()
    findUserName.whereKey("username", containsString: searchText.text)



    findUserName.findObjectsInBackgroundWithBlock{
        (objects:[AnyObject]!, error:NSError!) -> Void in

        if !(error != nil) {

            if let user:PFUser = users as? PFUser {
                cell.userNameTextField.text = user.username
                println("user exist")
                // define avatar poster

                if let avatarImage:PFFile = user["profileImage"] as? PFFile {
                    avatarImage.getDataInBackgroundWithBlock{(imageData:NSData!, error:NSError!)-> Void in

                        if !(error != nil) {

                            let image:UIImage = UIImage(data: imageData)


                            cell.avatarImage.image = image as UIImage
                            cell.avatarImage.layer.cornerRadius = 24
                            cell.avatarImage.clipsToBounds = true

                        }

                    }

                }
                else {
                    cell.avatarImage.image = UIImage(named: "Avatar-1")
                    cell.avatarImage.layer.cornerRadius = 24
                    cell.avatarImage.clipsToBounds = true
                }
            }

        }


    }

  return cell

}



override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(true)
    navigationController.navigationBar.hidden = false
    loadUser()

}


override func viewDidAppear(animated: Bool) {

}

override func viewDidLoad() {


    // Do any additional setup after loading the view, typically from a nib.
}

}

Answer 1

我怀疑这可能是由于您尝试从发生网络请求的后台线程重新加载表格视图。 UI 更新应该从主线程进行。

在您的 loadUser() 函数中，尝试从主线程重新加载您的 tableview，如下所示：

NSOperationQueue.mainQueue().addOperationWithBlock({
    self.tableView.reloadData()
})

这可能会解决您的问题。