我正在使用mvvm method.my代码，如下所示。
foodModel： -
class foodModel: NSObject {
var name :String!
var city :String!
var imageurl :String!
init?(dictionary :JSONDictionary) {
guard let name = dictionary["name"] as? String,
let imageurl = dictionary["imageurl"] as? String,
let city = dictionary["city"] as? String else {
return
}
self.name = name
self.city = city
self.imageurl = imageurl
}
}
foodDataSourceModel： -
class foodDataSourceModel: NSObject {
var dataListArray:Array<foodModel>? = []
init(array :Array<[String:Any]>?) {
super.init()
var newArray:Array<[String:Any]> = []
if array == nil{
newArray = self.getJsonDataStored1()
}
else{
newArray = array!
}
var datalist:Array<foodModel> = []
for dict in newArray{
let model = foodModel(dictionary: dict)
datalist.append(model!)
}
self.dataListArray = datalist
}
}
typealias dummyDataSource1 = foodDataSourceModel
extension dummyDataSource1{
func getJsonDataStored1() ->Array<Dictionary<String,String>>{
let jsonArray = [["name":"Anjapar","imageurl":"","city":"india"],["name":"Anjapar","imageurl":"","city":"india"]] as Array<Dictionary<String,String>>
return jsonArray
}
}
foodViewModel： -
class foodViewModel: NSObject {
var datasourceModel:foodDataSourceModel
init(withdatasource newDatasourceModel:foodDataSourceModel) {
datasourceModel = newDatasourceModel
}
func datafordisplay(atindex index: Int) -> foodModel {
return datasourceModel.dataListArray![index]
}
func numberOfItemsInSection(section:Int) -> Int {
return (datasourceModel.dataListArray?.count)!
}
func loadData(){
loadFromWebserviceData { (newDataSourceModel) in
self.datasourceModel = newDataSourceModel!
}
}
func loadFromWebserviceData(completion :@escaping (foodDataSourceModel?) -> ()){
let url = URL(string :"http://example.com")!
URLSession.shared.dataTask(with: url) { data, _, _ in
if let data = data {
let json = try! JSONSerialization.jsonObject(with: data, options: [])
//let dictionaries = json as! [JSONDictionary]
let array = json as! Array<[String:Any]>
let newDataSource:foodDataSourceModel = foodDataSourceModel(array: array)
// DispatchQueue.main.async {
//
// }
completion(newDataSource)
}
}.resume()
}
}
foodViewController： -
@IBOutlet private weak var tableView: UITableView!
private var foodViewModel :foodViewModel!
init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?, withViewModel viewModel:foodViewModel) {
super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
foodViewModel = viewModel
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
// tableView.register(UINib(nibName: "foodCell", bundle: nil), forCellReuseIdentifier: "cell")
foodViewModel.loadData()
self.tableView .reloadData()
// Do any additional setup after loading the view.
}
// func numberOfSections(in tableView: UITableView) -> Int {
// return restaurtantViewModel.numberOfItemsInSection(section: Int)
// }
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell:UITableViewCell = self.tableView.dequeueReusableCell(withIdentifier: "cell")! as! foodCell
//cell.setRestaurtantData(restaurtant: foodModel)
cell.textLabel?.text = "rtyuiop"
//
return cell
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
/*
}
*/
}
玻璃纸： -
class foodCell: UITableViewCell {
@IBOutlet weak var name: UILabel!
@IBOutlet weak var city: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
func setRestaurtantData(restaurtant:foodModel)
{
self.name.text = restaurtant.name
self.city.text = restaurtant.city
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
此处输出未获取。我需要在tableview中显示值。显示错误，因为无法从dataSource获取单元格
{
"query": "sandwich",
"results_count": 12,
"page": 1,
"results": [
{
"name": "Caffè Macs",
"coordinates": {
"lat": 37.330576,
"lng": -122.029739
},
"meals": ["breakfast", "lunch", "dinner"]
},
...
]
}
这是模式，所以从这里我需要得到的值为＆＃34; name＆＃34;，＆＃34; lng＆＃34;和＆＃34; lat＆＃34;。 从Json加载数据时存在一些问题。在urlsession任务中 - 显示为变量不可用。请检查。如何解决这个问题？
答案 0 :(得分：0)
请更新您的viewDidLoad()。您必须设置tableview的委托和数据源。
首先在课堂上设置： -
class yourClass: UIViewController,UITableViewDelegate , UITableViewDataSource
现在
override func viewDidLoad() {
super.viewDidLoad()
// tableView.register(UINib(nibName: "foodCell", bundle: nil), forCellReuseIdentifier: "cell")
foodViewModel.loadData()
self.tableView .delegate = self
self.tableview.dataSource = self
self.tableView .reloadData()
答案 1 :(得分：0)
从Web服务获取数据时，通常以异步方式完成。在viewDidLoad方法中，您将在开始获取数据的调用之后立即更新表视图。
override func viewDidLoad() {
...
// Start fetching the data
foodViewModel.loadData()
// Reloading the table view even though the data might not be ready
self.tableView.reloadData()
...
}
您可以通过将回调传递到loadData中的foodViewModel功能来解决此问题：
func loadData(completion: (() -> ()) {
loadFromWebserviceData { (newDataSourceModel) in
self.datasourceModel = newDataSourceModel!
completion()
}
}
然后在foodViewController中，您将等待更新表格视图，直到数据源准备好显示为止：
override func viewDidLoad() {
...
foodViewModel.loadData {
self.tableView.reloadData()
}
...
}
虽然上面的代码应该有效，但这只是为了突出您目前面临的问题，因此尽可能简单。