Getting Data from HTTP Request Xamarin - rest

Question

I want to get and pass data from my HTTPWebRequest to my sync page. I am new to MVVM so I don't know if I am correct but so far I can check if there is a result. I tried to watch a lots of video tutorials and forums still I can't find what I need. I was hoping you guys have a answer for me. I have been struggling with this for a week now.
The flow of my project:
- The user will login when it is correct, The user will be redirected to my sync page where it will get all the users data from my server and insert the data into SQLite Database.
My questions are:
1. How can I get the data and specific data from my HTTPWebRequest?
2. Is my HTTPWebRequest service correct?
3. Is my MVVM correct?
4. Is my navigation to my next page is correct?
My code:
LoginPage.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TBSMobileApplication.Data;
using TBSMobileApplication.ViewModel;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
namespace TBSMobileApplication.View
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class LoginPage : ContentPage
{
public LoginPageViewModel loginModel;
public LoginPage ()
{
InitializeComponent ();
BindingContext = new LoginPageViewModel();
MessagingCenter.Subscribe<LoginPageViewModel,string>(this, "Login Alert", (sender,Username) =>
{
DisplayAlert("Login Error", "Please fill-up the form", "Ok");
});
MessagingCenter.Subscribe<LoginPageViewModel, string>(this, "Connected", (sender, Username) =>
{
DisplayAlert("Connection Info", "Connected", "Ok");
});
MessagingCenter.Subscribe<LoginPageViewModel, string>(this, "Not Connected", (sender, Username) =>
{
DisplayAlert("Connection Info", "Not Connected", "Ok");
});
MessagingCenter.Subscribe<LoginPageViewModel, string>(this, "Http", (sender, Username) =>
{
DisplayAlert("Login Error", "Username or Password is incorrect", "Ok");
});
entUsername.Completed += (object sender, EventArgs e) =>
{
entPassword.Focus();
};
}
protected async Task OnAppearingAsync()
{
var db = DependencyService.Get<ISQLiteDB>();
var conn = db.GetConnection();
if (conn != null)
{
await conn.CreateTableAsync<UserTable>();
await conn.CreateTableAsync<RetailerTable>();
await conn.CreateTableAsync<ContactsTable>();
}
base.OnAppearing();
}
}
}
LoginPageViewModel.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Net;
using System.Text;
using System.Windows.Input;
using TBSMobileApplication.View;
using Xamarin.Essentials;
using Xamarin.Forms;
namespace TBSMobileApplication.ViewModel
{
public class LoginPageViewModel : INotifyPropertyChanged
{
void OnProperyChanged(string PropertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(PropertyName));
}
public string username;
public string password;
public string Username
{
get { return username; }
set
{
username = value;
OnProperyChanged(nameof(Username));
}
}
public string Password
{
get { return password; }
set
{
password = value;
OnProperyChanged(nameof(Password));
}
}
public ICommand LoginCommand { get; set; }
public LoginPageViewModel()
{
LoginCommand = new Command(OnLogin);
}
public void OnLogin()
{
if (string.IsNullOrEmpty(Username) || string.IsNullOrEmpty(Password))
{
MessagingCenter.Send(this, "Login Alert", Username);
}
else
{
var current = Connectivity.NetworkAccess;
if (current == NetworkAccess.Internet)
{
var link = "http://192.168.1.25:7777/TBS/test.php?User=" + Username + "&Password=" + Password;
var request = HttpWebRequest.Create(string.Format(#link));
request.ContentType = "application/json";
request.Method = "GET";
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
if (response.StatusCode != HttpStatusCode.OK)
{
Console.Out.WriteLine("Error fetching data. Server returned status code: {0}", response.StatusCode);
}
else
{
using (StreamReader reader = new StreamReader(response.GetResponseStream()))
{
var content = reader.ReadToEnd();
if (content.Equals("[]") || string.IsNullOrWhiteSpace(content) || string.IsNullOrEmpty(content))
{
MessagingCenter.Send(this, "Http", Username);
}
else
{
App.Current.MainPage.Navigation.PushAsync(new DatabaseSyncPage(), true);
}
}
}
}
}
else
{
MessagingCenter.Send(this, "Not Connected", Username);
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
}