Text editor in C#

Below is a basic example of a text editor using TextBox for text input and output and SaveFileDialog and OpenFileDialog for file operations. Copy and paste this code into a C# file (e.g., TextEditor.cs) and run it.

using System;
using System.IO;
using System.Windows.Forms;

class TextEditor : Form
{
    private TextBox textBox;
    private OpenFileDialog openFileDialog;
    private SaveFileDialog saveFileDialog;

    public TextEditor()
    {
        Text = "Text Editor";
        Size = new System.Drawing.Size(800, 600);
        FormBorderStyle = FormBorderStyle.FixedSingle;
        MaximizeBox = false;

        textBox = new TextBox();
        textBox.Multiline = true;
        textBox.Dock = DockStyle.Fill;
        Controls.Add(textBox);

        MenuStrip menuStrip = new MenuStrip();
        Controls.Add(menuStrip);

        ToolStripMenuItem fileMenu = new ToolStripMenuItem("File");
        menuStrip.Items.Add(fileMenu);

        ToolStripMenuItem openItem = new ToolStripMenuItem("Open");
        ToolStripMenuItem saveItem = new ToolStripMenuItem("Save");
        ToolStripMenuItem exitItem = new ToolStripMenuItem("Exit");

        fileMenu.DropDownItems.Add(openItem);
        fileMenu.DropDownItems.Add(saveItem);
        fileMenu.DropDownItems.Add(exitItem);

        openFileDialog = new OpenFileDialog();
        saveFileDialog = new SaveFileDialog();

        openItem.Click += (sender, e) => OpenFile();
        saveItem.Click += (sender, e) => SaveFile();
        exitItem.Click += (sender, e) => Close();
    }

    private void OpenFile()
    {
        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            try
            {
                string content = File.ReadAllText(openFileDialog.FileName);
                textBox.Text = content;
            }
            catch (IOException)
            {
                MessageBox.Show("Error reading the file", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }

    private void SaveFile()
    {
        if (saveFileDialog.ShowDialog() == DialogResult.OK)
        {
            try
            {
                File.WriteAllText(saveFileDialog.FileName, textBox.Text);
            }
            catch (IOException)
            {
                MessageBox.Show("Error writing to the file", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new TextEditor());
    }
}