Read and write Open XML files (MS Office 2007)

using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Reflection;
using System.Windows;
using Microsoft.Win32;
using XlsxReadWrite.Properties;

namespace XlsxReadWrite
{
    public partial class MainWindow : Window
    {
        private readonly DataTable data = new DataTable(Settings.Default.DataTableName, Settings.Default.DataTableNamespace);
        private readonly string tempDir = Settings.Default.TemporaryDirectory;
        private readonly string templateFile = Settings.Default.TempateFilePath;

        public MainWindow()
        {
            InitializeComponent();

            try
            {
                this.data.ReadXmlSchema(Settings.Default.DataTableXmlSchemaFileName);
            }
            catch
            {
                using (var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("XlsxReadWrite.Resources.XlsxReadWriteTable.xsd"))
                    this.data.ReadXmlSchema(stream);
            }

            this.dataGrid.ItemsSource = this.data.AsDataView();
        }

        private void ShowOpenFileDialog(object sender, RoutedEventArgs e)
        {
            var openFileDialog = new OpenFileDialog()
            {
                FileName = Settings.Default.InputFileName,
                DefaultExt = "*.xlsx",
                Filter = "Excel Workbook (.xlsx)|*.xlsx"
            };

            if (openFileDialog.ShowDialog(this) == true)
                Settings.Default.InputFileName = openFileDialog.FileName;
        }

        private void ShowSaveFileDialog(object sender, RoutedEventArgs e)
        {
            var saveFileDialog = new SaveFileDialog()
            {
                FileName = Settings.Default.OutputFileName,
                DefaultExt = "*.xlsx",
                Filter = "Excel Workbook (.xlsx)|*.xlsx"
            };

            if (saveFileDialog.ShowDialog(this) == true)
                Settings.Default.OutputFileName = saveFileDialog.FileName;
        }

        private void ReadInput(object sender, RoutedEventArgs e)
        {
            // Get the input file name from the text box.
            var fileName = this.inputTextBox.Text;

            // Delete contents of the temporary directory.
            XlsxRW.DeleteDirectoryContents(tempDir);

            // Unzip input XLSX file to the temporary directory.
            XlsxRW.UnzipFile(fileName, tempDir);

            IList<string> stringTable;
            // Open XML file with table of all unique strings used in the workbook..
            using (var stream = new FileStream(Path.Combine(tempDir, @"xl\sharedStrings.xml"),
                FileMode.Open, FileAccess.Read))
                // ..and call helper method that parses that XML and returns an array of strings.
                stringTable = XlsxRW.ReadStringTable(stream);

            // Open XML file with worksheet data..
            using (var stream = new FileStream(Path.Combine(tempDir, @"xl\worksheets\sheet1.xml"),
                FileMode.Open, FileAccess.Read))
                // ..and call helper method that parses that XML and fills DataTable with values.
                XlsxRW.ReadWorksheet(stream, stringTable, this.data);
        }

        private void WriteOutput(object sender, RoutedEventArgs e)
        {
            // Get the output file name from the text box.
            string fileName = this.outputTextBox.Text;

            // Delete contents of the temporary directory.
            XlsxRW.DeleteDirectoryContents(tempDir);

            // Unzip template XLSX file to the temporary directory.
            XlsxRW.UnzipFile(templateFile, tempDir);

            // We will need two string tables; a lookup IDictionary<string, int> for fast searching and 
            // an ordinary IList<string> where items are sorted by their index.
            IDictionary<string, int> lookupTable;

            // Call helper methods which creates both tables from input data.
            var stringTable = XlsxRW.CreateStringTables(this.data, out lookupTable);

            // Create XML file..
            using (var stream = new FileStream(Path.Combine(tempDir, @"xl\sharedStrings.xml"),
                FileMode.Create))
                // ..and fill it with unique strings used in the workbook
                XlsxRW.WriteStringTable(stream, stringTable);

            // Create XML file..
            using (var stream = new FileStream(Path.Combine(tempDir, @"xl\worksheets\sheet1.xml"),
                FileMode.Create))
                // ..and fill it with rows and columns of the DataTable.
                XlsxRW.WriteWorksheet(stream, this.data, lookupTable);

            // ZIP temporary directory to the XLSX file.
            XlsxRW.ZipDirectory(tempDir, fileName);

            // If checkbox is checked, show XLSX file in Microsoft Excel.
            if (this.openFileCheckBox.IsChecked == true)
                System.Diagnostics.Process.Start(fileName);
        }
    }
}