Xamarin 如何向服务器发送请求？

编写rest服务。当您按键时，需要调用用户注册方法。我想在请求正文中指定电话号码。告诉我如何正确调用书面方法？谢谢

public class RestService
{

    private HttpClient client;
    private object responseString;

    public RestService()
    {
        client = new HttpClient();
    }
    public void UserRegistration()
    {
        var webUrl = "http://mysite/WebAPI/Register?app=CxTaxiWebAPI&phone=";
        HttpRequestMessage request = new HttpRequestMessage();
        request.RequestUri = new Uri(webUrl);
        request.Method = HttpMethod.Get;
        request.Content = new StringContent("+375293972740", Encoding.UTF8, "application/json");
    }
}


public partial class MainPage : ContentPage
{
    RestService _restService = new RestService();
    public MainPage()
    {
        InitializeComponent();
    }
    private void EnterButton_Clicked(object sender, EventArgs e)
    {  
        _restService.UserRegistration();
    }
}

---

你能试试这样的吗

                using (var client = new HttpClient())
                {
                    client.BaseAddress = new Uri("http://mysite/WebAPI/");

                    client.DefaultRequestHeaders.Accept.Clear();

                    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                    var responseTask = client.PostAsync(String.Format("Register?app=CxTaxiWebAPI&phone={0}", "+375293972740"), new StringContent(json, Encoding.UTF8, "application/json"));

                    var response = responseTask.Result;

                    return response;
                }

---

谢谢这个选项对我有效：var responseTask=client.GetAsync（String.Format（“Register？app=CxTaxiWebAPI&phone={0}”，“%2B375297740”，Encoding.UTF8））；