How to make a Notepad in C#

By FoxLearn 10/6/2024 3:33:49 AM   7.37K
Creating a simple Notepad application in a C# Windows Forms Application is a great way to get familiar with Windows Forms and file handling.

How to make a Notepad in C#

Click New Project, then select Visual C# on the left, then Windows and then select Windows Forms Application. Name your project "Notepad" and then click OK

Drag and drop a MenuStrip onto the form.

Add the following items to the MenuStrip:

  • File
    • New
    • Open
    • Save
    • Save As
    • Exit
  • Help
    • About

Add a TextBox to the form. Set its properties:

  • Multiline: True
  • ScrollBars: Both
  • Dock: Fill (to make it fill the form)

Main Form Design

notepad

About Form Design

notepad

Double-click on the Open menu item to create the Click event handler.

private void openToolStripMenuItem_Click(object sender, EventArgs e)//Open file
{
    using (OpenFileDialog ofd = new OpenFileDialog() { Filter = "Text Documents|*.txt", ValidateNames = true, Multiselect = false })
    {
        if (ofd.ShowDialog() == DialogResult.OK)
        {
            try
            {
                using (StreamReader sr = new StreamReader(ofd.FileName))
                {
                    path = ofd.FileName;
                    Task<string> text = sr.ReadToEndAsync();//Read data from text file
                    textBox.Text = text.Result;//Set data to textbox
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }
}

Double-click on the New menu item to create the Click event handler.

private void newToolStripMenuItem_Click(object sender, EventArgs e)//New file
{
    path = string.Empty;
    textBox.Clear();//Clear data in textbox
}

Double-click on the Save menu item to create the Click event handler.

private async void saveToolStripMenuItem_Click(object sender, EventArgs e)//Save file
{
    if (string.IsNullOrEmpty(path))
    {
        using (SaveFileDialog sfd = new SaveFileDialog() { Filter = "Text Documents|*.txt", ValidateNames = true })
        {
            if (sfd.ShowDialog() == DialogResult.OK)
            {
                try
                {
                    path = sfd.FileName;
                    using (StreamWriter sw = new StreamWriter(sfd.FileName))
                    {
                        await sw.WriteLineAsync(textBox.Text);//Write data to text file
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }
    }
    else
    {
        try
        {
            using (StreamWriter sw = new StreamWriter(path))
            {
                await sw.WriteLineAsync(textBox.Text);//Write data to text file
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }
}

Double-click on the SaveAs menu item to create the Click event handler.

private async void saveAsToolStripMenuItem_Click(object sender, EventArgs e)//Save as
{
    //Open save file dialog
    using (SaveFileDialog sfd = new SaveFileDialog() { Filter = "Text Documents|*.txt", ValidateNames = true })
    {
        if (sfd.ShowDialog() == DialogResult.OK)
        {
            try
            {
                using (StreamWriter sw = new StreamWriter(sfd.FileName))
                {
                    await sw.WriteLineAsync(textBox.Text);//Write data to text file
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }
}

Double-click on the Exit menu item to create the Click event handler.

private void exitToolStripMenuItem_Click(object sender, EventArgs e)
{
    Application.Exit();//Exit your program
}

Double-click on the About menu item to create the Click event handler.

private void aboutToolStripMenuItem_Click(object sender, EventArgs e)
{
    using (frmAbout frm = new frmAbout())//Open about form
    {
        frm.ShowDialog();
    }
}

Your main form

public partial class Form1 : Form
{
    string path;
    public Form1()
    {
        InitializeComponent();
    }
}

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