Answer to Question #200542 in C# for sana

Question

Design a notepad application in WPF.

Answer 1

MainWindow.xaml

<Window x:Class="Notepad.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Notepad" Height="350" Width="525">
    
    <Grid>
        
        <TextBox Height="262" HorizontalAlignment="Left" Margin="12,29,0,0" Name="txtText" VerticalAlignment="Top" Width="479" />
        <Menu Height="23" HorizontalAlignment="Left" Name="menu1" VerticalAlignment="Top" Width="491" >
            <MenuItem Header="_File" >
                <MenuItem Header="_New" Click="mnuNew_Click" />
                <MenuItem Header="_Open" Click="mnuOpen_Click" />
                <MenuItem Header="_Save" Click="mnuSave_Click"/>
                <Separator />
                <MenuItem Header="_Exit" Click="mnuExit_Click"/>
            </MenuItem>
        </Menu>
    </Grid>
</Window>

App.xaml

<Application x:Class="Notepad.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
         
    </Application.Resources>
</Application>

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Microsoft.Win32;
using System.IO;


namespace Notepad
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private string fileName;
        private const string FILE_FILTER = "Text|*.txt|All|*.*";
        public MainWindow()
        {
            InitializeComponent();
        }


 
        /// <summary>
        ///New  menu item
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void mnuNew_Click(object sender, RoutedEventArgs e)
        {
            txtText.Text = "";
            fileName = "";
        }


        /// <summary>
        /// Open menu item
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void mnuOpen_Click(object sender, RoutedEventArgs e)
        {
            // Create OpenFileDialog
            OpenFileDialog openFileDlg = new OpenFileDialog();
            openFileDlg.Filter =FILE_FILTER;
            if (openFileDlg.ShowDialog() == true)
            {
                fileName = openFileDlg.FileName;
                txtText.Text = System.IO.File.ReadAllText(openFileDlg.FileName);
            }
            
        }
        /// <summary>
        /// Save menu item
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void mnuSave_Click(object sender, RoutedEventArgs e)
        {
            if (fileName == "")
            {
                SaveFileDialog saveFileDialog = new SaveFileDialog();
                saveFileDialog.Filter = FILE_FILTER;
                if (saveFileDialog.ShowDialog() == true)
                {
                    fileName = saveFileDialog.FileName;
                }
            }
            File.WriteAllText(fileName, txtText.Text);
            
        }
        /// <summary>
        /// Exit menu item
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void mnuExit_Click(object sender, RoutedEventArgs e)
        {
            this.Close();
        }
    }
}

Example