Question

我正在尝试将REST API中的JSON转换为Xamarin.iOS。虽然我能够从API获取数据，但不知道在TableView中没有填充数据。

视图模型

public class SchoolSelectionViewModel : BaseViewModel
{
    private readonly ISchoolNames _schoolService;
    public SchoolSelectionViewModel(ISchoolNames schoolService)
    {
        _schoolService = schoolService;
    }
    public override void Start()
    {
        IsLoading = true;
        _schoolService.GetFeedItems(OnDilbertItems, OnError);
    }

    private void OnDilbertItems(List<SchoolModel> list)
    {
        IsLoading = false;
        Items = list;
    }

    private void OnError(Exception error)
    {
        // not reported for now
        IsLoading = false;
    }

    private bool _isLoading;
    public bool IsLoading
    {
        get { return _isLoading; }
        set { _isLoading = value; RaisePropertyChanged(() => IsLoading); }
    }

    private List<SchoolModel> _items;
    public List<SchoolModel> Items
    {
        get { return _items; }
        set { _items = value; RaisePropertyChanged(() => Items); }
    }
    private MvvmCross.Core.ViewModels.MvxCommand<SchoolModel> _itemSelectedCommand;
    public System.Windows.Input.ICommand ItemSelectedCommand
    {
        get
        {
            _itemSelectedCommand = _itemSelectedCommand ?? new MvvmCross.Core.ViewModels.MvxCommand<SchoolModel>(DoSelectItem);
            return _itemSelectedCommand;
        }
    }

    private void DoSelectItem(SchoolModel item)
    {
        //ShowViewModel<DetailViewModel>(item);
    }
}

服务

public class SchoolNames : ISchoolNames
{
    public SchoolNames()
    {
    }
    public void GetFeedItems(Action<List<SchoolModel>> success, Action<Exception> error)
    {
        var url = "http://demo.imanage-school.com/api/configurations/schoolnames";

        var request = (HttpWebRequest)WebRequest.Create(url);
        try
        {
            request.BeginGetResponse(result => ProcessResponse(success, error, request, result), null);
        }
        catch (Exception exception)
        {
            error(exception);
        }
    }

    private void ProcessResponse(Action<List<SchoolModel>> success, Action<Exception> error, HttpWebRequest request, IAsyncResult result)
    {
        try
        {
            var response = request.EndGetResponse(result);
            using (var stream = response.GetResponseStream())
            using (var reader = new StreamReader(stream))
            {
                var json_data = reader.ReadToEnd();
                json_data = json_data.Replace("\"", string.Empty);
                json_data = json_data.Replace("\\", "\"");

                //if (text.StartsWith("\""))
                //{
                //    text = text.Remove(0, 1);
                //}
                //if (text.EndsWith("\""))
                //{
                //    text = text.Remove(text.Length-1, 1);
                //}
                List<SchoolModel> List = new List<SchoolModel>();

                //List = JsonConvert.DeserializeObject < List <SchoolModel>> text;
                //List = JsonConvert.DeserializeObject(< List < SchoolModel >> text);
                var objects = JsonConvert.DeserializeObject<List<SchoolModel>>(json_data);
                success(List);
            }
        }
        catch (Exception exception)
        {
            error(exception);
        }
    }

    private List<SchoolModel> ParseDilbertItemList(string text)
    {
        var root = JsonConvert.DeserializeObject<SchoolModel>(text);
        var jsondetails = JsonConvert.SerializeObject(text);
        var xml = XDocument.Parse(text);
        var items = xml.Descendants("item");
        var list = items.Select(x =>
                                new SchoolModel()
                                {
            Name = x.Element("title").Value,
            ApiUrl = ExtractHttpImg(x.Element("description").Value)
                                }).ToList();
        return list;
    }

    private string ExtractHttpImg(string value)
    {
        var startPos = value.IndexOf("http://");
        var endPos = value.IndexOf(".gif\"", startPos);
        return value.Substring(startPos, endPos + 4 - startPos);
    }
}

的ViewController

public partial class SchoolSelectionView : MvxViewController<SchoolSelectionViewModel>
{
    public SchoolSelectionView() : base("SchoolSelectionView", null)
    {
    }

    public override void ViewDidLoad()
    {
        base.ViewDidLoad();
        this.NavigationController.SetNavigationBarHidden(true,true);

        var source = new MvxStandardTableViewSource(tblSchoolSelection, "TitleText Name");
        this.CreateBinding(source).To<SchoolSelectionViewModel>(vm => vm.Items).Apply();
        this.CreateBinding(source).For(s => s.SelectionChangedCommand).To<SchoolSelectionViewModel>(vm => vm.ItemSelectedCommand).Apply();
        tblSchoolSelection.Source = source;
        tblSchoolSelection.ReloadData();
    }

    public override void DidReceiveMemoryWarning()
    {
        base.DidReceiveMemoryWarning();
        // Release any cached data, images, etc that aren't in use.
    }
}

我觉得绑定存在一些问题，但我无法修复它。

Answer 1

在服务：

中

import UIKit


var timer = Timer()
var intCount = 0
var seconds = 0

let greenColor = UIColor(red: 0/255.0, green: 255/255.0, blue: 0/255.0, alpha: 1.0)
let redColor = UIColor(red: 255/255.0, green: 0/255.0, blue: 0/255.0, alpha: 1.0)

// Start Button
@IBAction func Start(_ sender: Any)
{
    repeat
    {
        performTimer()
        intCount += 1
    }while intCount < 2

    StartHide.isHidden = true
}

func performTimer()
{
    timer1() // Execute -> Finish
    timer2() // Execute -> Finish
}

func timer1()
{

    // Set Seconds
    seconds = 30
    // Colour for 30 Seconds 
    view.backgroundColor = redColor
    // Run Timer
    timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(timerPage.counter), userInfo: nil, repeats: true)
}

func timer2()
{
    // Set Seconds
    seconds = 10
    // Colour for 10 Seconds 
    view.backgroundColor = greenColor
    // Run Timer
    timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(timerPage.counter), userInfo: nil, repeats: true)
}

func counter()
{

    seconds -= 1

    if (seconds == 0)
    {
        timer.invalidate()
    }

}

首先创建变量List<SchoolModel> List = new List<SchoolModel>(); //List = JsonConvert.DeserializeObject < List <SchoolModel>> text; //List = JsonConvert.DeserializeObject(< List < SchoolModel >> text); var objects = JsonConvert.DeserializeObject<List<SchoolModel>>(json_data); success(List);，然后反序列化JSON，但将其存储到新变量List中。但是，您然后将objects传递给List方法，但success实际上是空的。您可能希望以List结束以使其正常工作。

从MvvmCross Xamarin.iOS中的Web服务获取数据

1 个答案: