AddTaskPage.xaml.cs

using System;
using System.Collections.Generic;
using MyDailyTaskManger.Models;
using Xamarin.Forms;
using Newtonsoft.Json;
using System.IO;

namespace MyDailyTaskManger
{
    public partial class AddTaskPage : ContentPage
    {
        private String FileName;

        public AddTaskPage()
        {
            InitializeComponent();
            FileName = null;
        }

        public async void HandleForm(object sender, EventArgs eventArgs)
        {
            var task = new Task();
            task.title = this.title.Text;
            task.detail = this.details.Text;
            task.dateCreated = DateTime.Now.ToString();
            

            if (null != this.FileName)
            {
                string FullFileName = Path.Combine(App.FolderPath, this.FileName);
                task.fileName = FullFileName;
                string json = JsonConvert.SerializeObject(task);
                File.WriteAllText(FullFileName, json);

                bool ok = await DisplayAlert(
                "Success",
                $"{this.FileName} File updated",
                "Done",
                "Contine update"
                );

                if (ok == true)
                {
                    ViewTaskPage page = new ViewTaskPage(task);
                    // page.BindingContext = task;

                    await Navigation.PushAsync(page);
                }
                

            } else
            {
                this.FileName = $"{Path.GetRandomFileName()}.task.txt";
                string FullFileName = Path.Combine(App.FolderPath, this.FileName);
                task.fileName = FullFileName;
                string json = JsonConvert.SerializeObject(task);
                File.WriteAllText(FullFileName, json);

                bool ok = await DisplayAlert(
                "Success",
                $"{this.FileName} File Created",
                "Done",
                "Contine update"
                );
                if (ok == true)
                {
                    ViewTaskPage page = new ViewTaskPage(task);
                    // page.BindingContext = task;

                    await Navigation.PushAsync(page);
                }
            }



        }
    }
}