【发布时间】：2018-03-15 22:41:46
【问题描述】：
我在 firebase 中有大量数据显示在 tableview 上。数据来自附近不同的企业，我想添加一个功能来按业务类型（食品、旅游、购物等）过滤/排序数据。我添加了一个带有分段控件的选项卡栏，用作过滤/排序功能。当用户选择购物时，我只希望显示购物业务并删除所有其他业务。我尝试了几种不同的方法来做到这一点，但都没有成功。当应用程序首次加载时，我能够正确填充表格视图单元格，但在选择过滤器/排序选项时我无法正确加载单元格。这是我当前的代码。
@IBOutlet weak var selects: UISegmentedControl!
@IBAction func selections(_ sender: Any) {
if selects.selectedSegmentIndex == 0 {
//all
print("all")
cate = 0
loadposts()
}
else if selects.selectedSegmentIndex == 1 {
//shopping
print("shopping")
cate = 1
loadposts()
}
else if selects.selectedSegmentIndex == 2 {
//food
print("food")
cate = 2
loadposts()
}
else if selects.selectedSegmentIndex == 3 {
//travel
print("travel")
cate = 3
loadposts()
}
else if selects.selectedSegmentIndex == 4 {
//events
print("event")
cate = 4
loadposts()
}
else {
//more
print("more")
cate = 5
loadposts()
}
}
func loadposts() {
ref = Database.database().reference()
let trace = Performance.startTrace(name: "test trace")
trace?.incrementCounter(named:"retry")
let userID = Auth.auth().currentUser?.uid
print(userID!)
ref.child("Users").child(userID!).observeSingleEvent(of: .value, with: { (snapshot) in
// Get user value
let value = snapshot.value as? NSDictionary
let one1 = value?["Coupon Book"] as? String ?? ""
let two2 = value?["charitylogo"] as? String ?? ""
print("one1: \(one1)")
bogus.set(one1, forKey: "bogus")
let url = URL(string: two2)
print("Url: \(url!)")
URLSession.shared.dataTask(with: url!, completionHandler: { (data, response, error) in
if error != nil{
print(error)
return
}
DispatchQueue.main.async {
/// self.centernavlogo = UIButton(type: .custom)
let pim = UIImage(data: data!)
self.vood.background = pim
///self.centernavlogo.frame = CGRect(x: 0, y: 0, width: 30, height: 30)
/// self.centernavlogo.imageView?.contentMode = .scaleAspectFit
/// self.centernavlogo.setImage(pim, for: .normal)
/// self.centernavlogo.setBackgroundImage(pim, for: .normal)
/// self.centernavlogo.tintColor = UIColor.white
///self.centernavlogo.setBackgroundImage(pim, for: .normal)
}
}).resume()
Database.database().reference().child("Coupons").child(one1).observe(.childAdded) { (Snapshot : DataSnapshot) in
if let dict = Snapshot.value as? [String: Any] {
let captiontext = dict["company name"] as! String
let offerx = dict["totaloffer"] as! String
let logocomp = dict["logo"] as! String
let actchild = dict["childx"] as! String
let categ = dict["category"] as! String
let post = Post(captiontext: captiontext, PhotUrlString: actchild, offertext: offerx, actualphoto: logocomp, cat2: categ)
self.posts.append(post)
self.tableview.reloadData()
print(self.posts)
}
}
}) { (error) in
print(error.localizedDescription)
}
trace?.stop()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func delay(_ delay:Double, closure:@escaping ()->()) {
let when = DispatchTime.now() + delay
DispatchQueue.main.asyncAfter(deadline: when, execute: closure)
}
}
extension ViewController : UITableViewDataSource {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableview.dequeueReusableCell(withIdentifier: "PostCell", for: indexPath) as! prot
if cate == 0{
///home
if posts[indexPath.row].cat1 == "" {
}else{
}
}else
if cate == 1{
///shopping
if posts[indexPath.row].cat1 == "shopping" {
}
}else
if cate == 2{
///food
if posts[indexPath.row].cat1 == "food" {
}
}else
if cate == 3{
///travel
if posts[indexPath.row].cat1 == "travel" {
}
}else
if cate == 4{
///event
if posts[indexPath.row].cat1 == "event" {
}
}else
if cate == 5{
///more
if posts[indexPath.row].cat1 == "more" {
posts.remove(at: indexPath.item)
DispatchQueue.main.async {
tableView.deleteRows(at: [indexPath], with: UITableViewRowAnimation.none)
}
print("category 5 running")
}
tableView.reloadData()
}
if cate == 6{
///gps
}
cell.cllimg?.image = nil
cell.maintxt.text = nil
cell.sidetxt.text = nil
cell.maintxt.text = posts[indexPath.row].caption
cell.sidetxt.text = "Offers: \(posts[indexPath.row].offercount)"
let hone = posts[indexPath.row]
if let maria = hone.actphot {
let url = URL(string: maria)
URLSession.shared.dataTask(with: url!, completionHandler: { (data, response, error) in
if error != nil{
print(error)
return
}
cell.cllimg?.contentMode = .scaleAspectFit
DispatchQueue.main.async {
cell.cllimg?.image = UIImage(data: data!)
}
}).resume()
}
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
passinfo.set("\(posts[indexPath.row].photourl)", forKey: "passinfo")
self.performSegue(withIdentifier: "yourSegue", sender: self)
}
}
使用上面的代码，选择类别时表格为空白
if cate == 5{
///more
if posts[indexPath.row].cat1 == "more" {
tableView.beginUpdates()
posts.remove(at: indexPath.item)
tableView.deleteRows(at: [indexPath], with: UITableViewRowAnimation.none)
print("category 5 running")
}
tableView.endUpdates()
}
使用上面的代码，应用程序崩溃并给我这个错误。
由于未捕获的异常'NSInternalInconsistencyException'而终止应用程序，原因：'无效更新：第0节中的行数无效。更新后现有节中包含的行数（14）必须等于行数更新前包含在该节中 (15)，加上或减去从该节插入或删除的行数（0 插入，0 删除），加上或减去移入或移出该节的行数（0 移入, 0 移出）。'
我也尝试删除 posts.remove(at: indexPath.item) 和 tableView.deleteRows(at: [indexPath], with: UITableViewRowAnimation.none)，但都没有成功。
【问题讨论】：
-
考虑只使用 cate = selects.selectedSegmentIndex 而不是整个 if else 构造。我认为崩溃正是在解释问题所在。
标签： swift uitableview firebase-realtime-database