我的要求：我将在表视图中显示聊天详细信息列表。在表视图顶部，将使用文本字段进行搜索。基于用户的唯一ID，应完成搜索。不是用户输入的具有唯一ID的聊天，那么它必须重定向到另一个称为chatcreatepage的屏幕。每当我们搜索聊天时，我们都会使用一个名为FIND API的API，并且在该FIND API中有一个聊天字典，如果为null，则将调用create chat。如果该聊天字典不为nil，则需要显示聊天列表视图中的聊天详细信息。当加载聊天列表页面时，我们将调用聊天列表Api。当我们通过在文本字段中输入唯一ID进行搜索时，我们将获取输入的唯一ID和我们拥有的唯一ID详细信息在表格视图中显示。
这是任务，我已经完成，直到表中显示聊天列表。FINDAPI集成也已完成。当我用搜索结果重新加载数据（找到api响应）时，出现致命错误，例如“意外在“ var recepient = dict [“ recipient”] as！[String：Any]“行中解开可选值时发现nil。如果有人帮助我解决问题，那就太好了。谢谢您。我在下面提供了代码。
import UIKit
import Alamofire
import SwiftyJSON
import SDWebImage
class ChatlistViewController: UIViewController{
var pro = [[String:Any]]()
var dict:[String:Any]!
var idd = ""
var id = ""
var chatt:Dictionary = [String:Any]()
var searchActive : Bool = false
var filtered:[String] = []
var data:[String] = []
@IBOutlet weak var searchtext: UITextField!
@IBOutlet weak var chatlisttable: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
apicall()
}
func apicall(){
let acce:String = UserDefaults.standard.string(forKey: "access-tokenn")!
print(acce)
let headers:HTTPHeaders = ["Authorization":"Bearer \(acce)","Content-Type":"application/X-Access-Token"]
Alamofire.request(Constants.Chatlist, method: .get, encoding: URLEncoding.default, headers: headers).responseJSON { response in
switch response.result {
case .success:
print(response)
if response.result.value != nil{
var maindictionary = NSDictionary()
maindictionary = response.result.value as! NSDictionary
print(maindictionary)
var userdata = NSDictionary()
userdata = maindictionary.value(forKey: "data") as! NSDictionary
var productsdetails = [[String:Any]]()
productsdetails = userdata.value(forKey: "chat") as! [[String:Any]]
self.pro = productsdetails
print(self.pro)
self.chatlisttable.reloadData()
}else{
let Alertcontroller = UIAlertController(title: "Alert", message: "No data found ", preferredStyle: .alert)
let CancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)
Alertcontroller.addAction(CancelAction)
self.present(Alertcontroller, animated: true, completion: nil)
}
break
case .failure(let error):
print(error)
}
}
}
func searchapicall(){
idd = searchtext.text!
let acce:String = UserDefaults.standard.string(forKey: "access-tokenn")!
print(acce)
let headers:HTTPHeaders = ["Authorization":"Bearer \(acce)","Content-Type":"application/X-Access-Token"]
print((Constants.Chatlistsearch)+(idd))
Alamofire.request((Constants.Chatlistsearch+idd), method: .get, encoding: URLEncoding.default, headers: headers).responseJSON { response in
switch response.result {
case .success:
//print(response)
if response.result.value != nil{
var maindictionary = NSDictionary()
maindictionary = response.result.value as! NSDictionary
var chat:Dictionary = maindictionary.value(forKey: "data") as! [String:Any]
var chattt:Dictionary = chat["chat"] as! [String:Any]
if (chattt != nil) {
// print("Find Action")
self.chatt = chat["user"] as! [String:Any]
print(self.chatt)
self.pro = [self.chatt]
// print(self.pro)
self.chatlisttable.reloadData()
}else{
let viewc = UIStoryboard.init(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "ChatViewController") as? ChatViewController
self.navigationController?.pushViewController(viewc!, animated: true)
}
}else{
let Alertcontroller = UIAlertController(title: "Alert", message: "No data found on this unique id", preferredStyle: .alert)
let CancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)
Alertcontroller.addAction(CancelAction)
self.present(Alertcontroller, animated: true, completion: nil)
}
break
case .failure(let error):
print(error)
}
}
}
}
extension ChatlistViewController: UITextFieldDelegate{
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
self.searchapicall()
return true
}
}
extension ChatlistViewController: UITableViewDataSource,UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if (searchActive == false){
return self.pro.count
}else{
return 1
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = chatlisttable.dequeueReusableCell(withIdentifier: "ChatlistTableViewCell", for: indexPath) as! ChatlistTableViewCell
if (searchActive == false){
dict = pro[indexPath.row]
var recepient = dict["recipient"] as! [String:Any]
print(recepient)
var name = recepient["name"] as! String
print(name)
id = recepient["unique_id"] as! String
print(id)
var image = recepient["avatar"] as! String
print(image)
cell.namelbl.text = name
cell.idlbl.text = id
cell.imageView!.sd_setImage(with: URL(string:image), placeholderImage: UIImage(named: "Mahi.png"))
}else{
cell.namelbl.text = chatt["name"] as! String
cell.idlbl.text = chatt["unique_id"] as! String
}
return cell
self.chatlisttable.reloadData()
}
}
//Response format
{
"success": 1,
"status": 200,
"data": {
"user": {
"id": 3,
"unique_id": "10002",
"name": "nani",
"avatar": "https://www.planetzoom.co.in/storage/user/avatar/AkgcUFF3QIejMhZuLF4OXnSFHjxNAOo4FuXV3Mgi.jpeg"
},
"chat": null
}
}
//Response with chat dictionary data
{
"success": 1,
"status": 200,
"data": {
"user": {
"id": 8,
"unique_id": "10007",
"name": "Mahitha",
"avatar": "https://www.planetzoom.co.in/storage/user/avatar/cZt9yQlBzIEewOdQ1lYZhl3dFiOv2k3bxG7HLOzR.jpeg"
},
"chat": {
"id": 4,
"status": 0,
"created_at": "2019-02-27 12:26:24",
"updated_at": "2019-02-27 12:26:24"
}
}
}
答案 0 :(得分：1)
由于我在回复中看到chat为零，因此您应该更新代码以获取聊天详细信息
if var productsdetails = userdata.value(forKey: "chat") as? [[String:Any]] {
// Code to display chat
} else {
// Code to display nil error
}
我希望这能解决您的问题。
答案 1 :(得分：1)
根据您的回复聊天为空。因此，productsdetails = userdata.value(forKey: "chat") as! [[String:Any]]就是这样，您已经在键'chat'的userdefaults中设置了一个空值，并且正在以[[String : Any]]
所以您必须使用代码块
进行检查if let productsdetails = userdata.value(forKey: "chat") as? [[String:Any]] {
// write code that for chat
} else {
// write code for chat is null
}
这称为Optional Chaining，您可能会发现此link
可选链接是一个查询和调用可选当前可能为零的属性，方法和下标的过程。如果可选包含值，则属性，方法或下标调用成功；否则，调用成功。如果可选值为nil，则属性，方法或下标调用将返回nil。可以将多个查询链接在一起，如果链中的任何链接为nil，整个链都会正常失败。
或者您可以使用guard语句
guard let productsdetails = userdata.value(forKey: "chat") as? [[String:Any]] else {
// write code for chat is null
return
}
\\ write code that for chat
\\ you can use productsdetails variable here
答案 2 :(得分：0)
我想向您提供两个反馈：
请尝试养成避免forced casting或forced unwrap成为可能的习惯。
使用驼峰式命名约定
因此，您可以更改
var recepient = dict["recipient"] as! [String:Any]
到
guard let recepient = dict["recipient"] as? [String:Any] else {return cell}
以类似的方式可以在加载tableView之前具有条件
if let productsDetails = userdata.value(forKey: "chat") as? [[String:Any]] {
// write code
} else {
// write code to handle else
}