Question

在我以前的文章中，我问过有关使用C＃正文从Http Get Request获取数据的问题。现在我面临另一个错误，int(root.frame(),16) # root is a Tk() or Toplevel()有人知道如何解决此问题吗？

代码

Android.Util.AndroidRuntimeException: 'Only the original thread that created a view hierarchy can touch its views.'

Answer 1

尝试以下类似操作（假设整件事是一个名为“ SomeFunction”的函数）

private void SomeFunction() {
 Device.BeginInvokeOnMainThread(() => {
  var client = new HttpClient();

  var request = new HttpRequestMessage {
   Method = HttpMethod.Get,
    RequestUri = new Uri("my url"),
    Content = new StringContent("my json body content", Encoding.UTF8, "application/json"),
  };

  var response = await client.SendAsync(request).ConfigureAwait(false);
  response.EnsureSuccessStatusCode();
  var responsebody = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
  string text = responsebody.ToString();
  string[] str = text.Split(new [] {
   ',',
   ':'
  }, StringSplitOptions.RemoveEmptyEntries);
  string result = str[10];
  labelTxt.Text = result;
 });
}

Answer 2

嗨，请尝试以下代码。

public async static Task<T> GetResultAsync<T>(string Url)
{
    try
    {
        if (CrossConnectivity.Current.IsConnected)
        {
            using (var client = new HttpClient())
            {
                client.BaseAddress = new Uri(BaseUrl);
                client.DefaultRequestHeaders.Clear();
                client.SetBearerToken(Helpers.Settings.ServiceToken);
                client.DefaultRequestHeaders.Add("Language", Helpers.Settings.AppLanuageSetting);
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                HttpResponseMessage response = await client.GetAsync($"{Url}").ConfigureAwait(false);
                if (response.IsSuccessStatusCode)
                {
                    var result = await response.Content.ReadAsStringAsync();
                    return JsonConvert.DeserializeObject<T>(result,new JsonSerializerSettings { PreserveReferencesHandling = PreserveReferencesHandling.None });
                }
                else
                {
                    return default(T);
                }
            }
        }
        else
        {
            Acr.UserDialogs.UserDialogs.Instance.Toast("Please check your internet connection");
            return default(T);
        }
    }
    catch (Exception Ex)
    {
        Logging.ErrorLog(Ex, "GetResultAsync");
        return default(T);
    }
}

并使用此方法

var结果=等待APIService.GetResultAsync>（$“ {ApiEndpoints} / {” Paramters1“} / {pageNo}”）;

Answer 3

如上面curiousBoy所说，您只能从UI线程（主线程）修改UI元素。

因此您可以尝试将<Button title="Add User" onPress={() => this.props.navigation.navigate('AddNewUser')} />放在labelTxt.Text = result;方法中。

Device.BeginInvokeOnMainThread

无法显示来自响应主体HttpClient的数据获取请求

3 个答案: