API结果未显示C#UWP

大家好，

我正在尝试使用API来显示当前比特币的价格。 API返回结果和所有内容，但它不会在UWP应用程序上显示

奇怪的是，它确实显示了一次结果，但此后再也没有显示结果

• 是的，API非常快

这是我的主页代码：

public sealed partial class MainPage : Page, INotifyPropertyChanged
{
    public string Price { get; set; }

    private DispatcherTimer _timer;

    public event PropertyChangedEventHandler PropertyChanged;

    public MainPage()
    {
        this.InitializeComponent();

        this._timer = new DispatcherTimer();
        this._timer.Interval = TimeSpan.FromSeconds(20);
        this._timer.Tick += OnUpdate;

        this._timer.Start();
    }

    private async void OnUpdate(object sender, object e)
    {
        this.Price = (await API.GetData(1))[0]["price_eur"];
        this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Price"));
    }
}

class API
{
    public static async Task<List<Dictionary<string, string>>> GetData(int limit)
    {
        var url = "https://api.coinmarketcap.com/v1/ticker/?convert=EUR&limit=" + limit;

        using (var client = new HttpClient())
        {
            var response = await client.GetAsync(url);

            if (response.IsSuccessStatusCode)
            {
                var result = await response.Content.ReadAsStringAsync();

                return JsonConvert.DeserializeObject<List<Dictionary<string, string>>>(result);
            }
            else
            {
                return null;
            }
        }
    }
}

<RelativePanel>
        <Rectangle x:Name="rctOrange" Fill="Orange" RelativePanel.AlignRightWithPanel="True" RelativePanel.AlignBottomWithPanel="True" Stretch="UniformToFill"/>
        <TextBlock x:Name="tbPrice" FontSize="80" Text="{x:Bind Price, Mode=OneWay}" RelativePanel.AlignVerticalCenterWith="rctOrange" RelativePanel.AlignHorizontalCenterWith="rctOrange"/>
</RelativePanel>

这是我的API类代码：

public sealed partial class MainPage : Page, INotifyPropertyChanged
{
    public string Price { get; set; }

    private DispatcherTimer _timer;

    public event PropertyChangedEventHandler PropertyChanged;

    public MainPage()
    {
        this.InitializeComponent();

        this._timer = new DispatcherTimer();
        this._timer.Interval = TimeSpan.FromSeconds(20);
        this._timer.Tick += OnUpdate;

        this._timer.Start();
    }

    private async void OnUpdate(object sender, object e)
    {
        this.Price = (await API.GetData(1))[0]["price_eur"];
        this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Price"));
    }
}

class API
{
    public static async Task<List<Dictionary<string, string>>> GetData(int limit)
    {
        var url = "https://api.coinmarketcap.com/v1/ticker/?convert=EUR&limit=" + limit;

        using (var client = new HttpClient())
        {
            var response = await client.GetAsync(url);

            if (response.IsSuccessStatusCode)
            {
                var result = await response.Content.ReadAsStringAsync();

                return JsonConvert.DeserializeObject<List<Dictionary<string, string>>>(result);
            }
            else
            {
                return null;
            }
        }
    }
}

<RelativePanel>
        <Rectangle x:Name="rctOrange" Fill="Orange" RelativePanel.AlignRightWithPanel="True" RelativePanel.AlignBottomWithPanel="True" Stretch="UniformToFill"/>
        <TextBlock x:Name="tbPrice" FontSize="80" Text="{x:Bind Price, Mode=OneWay}" RelativePanel.AlignVerticalCenterWith="rctOrange" RelativePanel.AlignHorizontalCenterWith="rctOrange"/>
</RelativePanel>

类API
{
公共静态异步任务GetData（整数限制）
{
变量url=”https://api.coinmarketcap.com/v1/ticker/?convert=EUR&limit=“+限制；
使用（var client=new HttpClient（））
{
var response=wait client.GetAsync（url）；
if（响应。IsSuccessStatusCode）
{
var result=await response.Content.ReadAsStringAsync（）；
返回JsonConvert.DeserializeObject（结果）；
}
其他的
{
返回null；
}
}
}
}

这是我的主页xaml代码：

public sealed partial class MainPage : Page, INotifyPropertyChanged
{
    public string Price { get; set; }

    private DispatcherTimer _timer;

    public event PropertyChangedEventHandler PropertyChanged;

    public MainPage()
    {
        this.InitializeComponent();

        this._timer = new DispatcherTimer();
        this._timer.Interval = TimeSpan.FromSeconds(20);
        this._timer.Tick += OnUpdate;

        this._timer.Start();
    }

    private async void OnUpdate(object sender, object e)
    {
        this.Price = (await API.GetData(1))[0]["price_eur"];
        this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Price"));
    }
}

class API
{
    public static async Task<List<Dictionary<string, string>>> GetData(int limit)
    {
        var url = "https://api.coinmarketcap.com/v1/ticker/?convert=EUR&limit=" + limit;

        using (var client = new HttpClient())
        {
            var response = await client.GetAsync(url);

            if (response.IsSuccessStatusCode)
            {
                var result = await response.Content.ReadAsStringAsync();

                return JsonConvert.DeserializeObject<List<Dictionary<string, string>>>(result);
            }
            else
            {
                return null;
            }
        }
    }
}

<RelativePanel>
        <Rectangle x:Name="rctOrange" Fill="Orange" RelativePanel.AlignRightWithPanel="True" RelativePanel.AlignBottomWithPanel="True" Stretch="UniformToFill"/>
        <TextBlock x:Name="tbPrice" FontSize="80" Text="{x:Bind Price, Mode=OneWay}" RelativePanel.AlignVerticalCenterWith="rctOrange" RelativePanel.AlignHorizontalCenterWith="rctOrange"/>
</RelativePanel>

我希望你们能找到问题所在，因为我快疯了

---

提前感谢

您不应该在页面上实现INotifyPropertyChanged。您应该创建一个实现INotifyPropertyChanged的ViewModel

private async void OnUpdate(object sender, object e)
{
    this.Price.Value = (await API.GetData(1))[0]["price_eur"];
}

class PriceModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    private string _value;
    public string Value
    {
        get { return _value; }
        set
        {
            _value = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Value"));
        }
    }
}

---

如果您不向我们提供有关出现问题的信息，我们将无法帮助您。简单地问“为什么这不起作用”并不是这个论坛的主题。是否有任何错误，到目前为止需要调试什么？@Glubus没有错误，程序正常启动。API调用返回正确的信息，但唯一的问题是它不会在应用程序中放置“price_eur”。我理解，但我试图向您传达，我们需要更多的信息来帮助您。您要求我们为您找到一个问题，以便您/我们能够解决它。你需要提出一个具体的问题，你需要帮助，而不是离开这个论坛的工作。谢谢，这个答案帮了我很多！