using System;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using Windows.Storage;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

// 空白ページの項目テンプレートについては、https://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x411 を参照してください

namespace App2
{
    /// <summary>
    /// それ自体で使用できる空白ページまたはフレーム内に移動できる空白ページ。
    /// </summary>
    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
        }
        private const string OutFile = @"sample.txt";

        private async void SaveFile_Click(object sender, RoutedEventArgs e)
        {
            SaveFile.IsEnabled = false;
            await AddTextToFile();
            SaveFile.IsEnabled = true;
            SaveFile.Content = "Created!!";
        }

        public async Task AddTextToFile()
        {
            StorageFolder folder = Windows.Storage.ApplicationData.Current.LocalFolder;
            StorageFile samplefile = await folder.CreateFileAsync(OutFile, CreationCollisionOption.ReplaceExisting);
            string text =
@"Line 01
Line 02
";
            await FileIO.WriteTextAsync(samplefile, text);
            await FileIO.AppendTextAsync(samplefile, text);

            var lines = await FileIO.ReadLinesAsync(samplefile);
            foreach (var l in lines)
                System.Diagnostics.Debug.WriteLine(l);

            await FileIO.WriteTextAsync(samplefile, text);
            var lines2 = await FileIO.ReadLinesAsync(samplefile);
            foreach (var l in lines2)
                System.Diagnostics.Debug.WriteLine(l);
        }
    }
}