Question

在Xamarin Forms中，我想在应用启动时调用node.js服务。在App.xaml.cs中我有这个：

protected override async void OnStart()
{
      await CheckDeviceRegistered("1231234");
}

private async Task<bool> CheckDeviceRegistered(string id)
{
     try
     {
         return await _deviceService.GetDevice(id);
     }
         catch (Exception e)
     {
         return false;
     }
}

称之为：

public class DeviceRegisteredService : IDeviceRegisteredService
    {
        #region IDeviceRegistered
        public async Task<bool> GetDevice(string deviceID)
        {
            HttpResponseMessage result;
            string url = Resources.DeviceApi.Get + "?id=" + deviceID;
            result = await App.HttpClientInstance().GetAsync(url);

            if (result.StatusCode == System.Net.HttpStatusCode.OK)
            {
                return true;
            }
            return false;


            throw new InvalidOperationException();
        }
        #endregion
    }


public interface IDeviceRegisteredService
{
    Task<bool> GetDevice(string ID);
}

我可以在浏览器中或通过Postman调用该服务，但是当我调试时，我点击了

result = await App.HttpClientInstance().GetAsync(url);


public static HttpClient _httpClientInstance;
 public static HttpClient HttpClientInstance()
  {
      if (_httpClientInstance == null)
      {
           _httpClientInstance = new HttpClient();
      }

            return _httpClientInstance;
   }

没有任何反应，没有错误或崩溃，但代码似乎停止了。我想我在这里错过了一步，有人能指出我需要什么吗？

在Xamarin Forms中调用node.js服务

0 个答案: