滚动后,UITableview单元格不会显示

Question

快速上下文,我有一个视图控制器,可以选择通过单击UIButton添加朋友.我想自定义这个控制器,而不是使用peoplepicker,所以我创建了自己的tableview,我填写了地址簿中的信息.首先,我问用户是否可以访问他们的地址簿.然后我将他们的联系人姓名放入一个数组中以填充tableview.最奇怪的是,在您第一次滚动tableview之前,名称不会显示在表格单元格中.当我停下来重新启动或者只是放松并回来时,细胞就像你期望的那样填充.当我重置内容并重新启动时,同样的事情发生在滚动之前名称不会显示在单元格中.对可能发生的事情的任何想法？提前致谢!

import UIKit
import AddressBook

class ContactsViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet weak var namesTableView: UITableView!

    var addressBook: ABAddressBook!
    var names:[String]?

    func createAddressBook() {

        var error: Unmanaged<CFErrorRef>?

        addressBook = ABAddressBookCreateWithOptions(nil, &error).takeRetainedValue()

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        self.namesTableView.delegate = self
        self.namesTableView.dataSource = self

        accessAddressBook()

        self.namesTableView.backgroundColor = UIColor(red: 74/255, green: 144/255, blue: 226/255, alpha: 1)
        self.namesTableView.allowsMultipleSelection = true

    }

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

    func accessAddressBook () {

        switch ABAddressBookGetAuthorizationStatus(){
        case .Authorized:
            println("Already authorized")
            createAddressBook()
            self.beginContactSearch()

        case .Denied:
            println("You are denied access to the address book")

        case .NotDetermined:
            createAddressBook()
            if let theBook: ABAddressBook = addressBook {

                ABAddressBookRequestAccessWithCompletion(theBook, {(granted: Bool, error: CFError!) in

                    if granted {

                        println("Access is granted")
                        self.beginContactSearch()
                    }
                    else {

                        println("Access is not granted")
                    }
                })
            }
        case .Restricted:
            println("Access is restricted")

        default:
            println("Unhandled")
        }

    }

    func beginContactSearch(){
        let records = ABAddressBookCopyArrayOfAllPeople(self.addressBook).takeRetainedValue() as NSArray as [ABRecord]
        names = Array()
        for record in records {
            let object = ABRecordCopyCompositeName(record)
            if object.toOpaque() == COpaquePointer.null() {

            } else {
                var name = object.takeRetainedValue() as NSString
                self.names!.append(name)
            }
            self.namesTableView.reloadData()
        }
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.names?.count ?? 0
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = namesTableView.dequeueReusableCellWithIdentifier("Tablecell") as UITableViewCell

        cell.textLabel!.text = names![indexPath.row]
        cell.textLabel?.textColor = UIColor.whiteColor()
        cell.backgroundColor = UIColor(red: 74/255, green: 144/255, blue: 226/255, alpha: 1)

        return cell
    }

    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        var selectedCell:UITableViewCell = tableView.cellForRowAtIndexPath(indexPath)!
        selectedCell.contentView.backgroundColor = UIColor.whiteColor()
        selectedCell.textLabel?.textColor = UIColor(red: 74/255, green: 144/255, blue: 226/255, alpha: 1)

        println("User selected: \(self.names?[indexPath.row])")

    }

    func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
        var cellToDeSelect:UITableViewCell = tableView.cellForRowAtIndexPath(indexPath)!

        cellToDeSelect.textLabel?.textColor = UIColor.whiteColor()

    }

}

Answer 1

在主线程上运行.reloadData:

dispatch_async(dispatch_get_main_queue()) {
     self.namesTableView.reloadData()
}

它应该工作.