mosessaur

//used when create new document to add a number to the document name like
//"myDoc0.txt", so when you create another one it will be "myDoc1.txt"
private int m_intDocNumber = 0;

//Hold the file name that created or choosed
//for the Save action, not "Save As..."
private string m_strFileName = "";

//Hold the DialogResult enum result
//Ok or Cancel
private DialogResult dlgResult;

//Stream to write to the file
private StreamWriter m_sw;

//Check if the file is modified or not
private bool m_bModified = false;

//The TextChanged Event for the txtBody Control
private void txtBody_TextChanged(object sender, System.EventArgs e)
{
    m_bModified = true; //Document has been modified.
}

//This Method check if the Text has beed modified or not
//if yes display a message asking if the user wants to save his work or not
private void CheckChanged(object sender, System.EventArgs e)
{
    if(m_bModified)
    {
        dlgResult = MessageBox.Show("Do you want to 
save?","Note",MessageBoxButtons.YesNo,MessageBoxIcon.Exclamation);
        if(dlgResult == DialogResult.Yes)
        {
            //Calling the menuItemSave_Click Mthod
                        // to save the current work document
            menuItemSave_Click(sender,e);
        }
    }
}

private void menuItemNew_Click(object sender, System.EventArgs e)
{
        // Check if the current work document is not 
        // completely saved.

        CheckChanged(sender,e);    
        // cleare the file name so when click on Save menu Item 
        // it will not overwrite an old document

        m_strFileName = "";     

        // cleare the editor area.
        txtBody.Clear(); 
    
        // new document means not modified yet.    
        m_bModified = false; 
        
        /*

        do not replace the m_bModified position in this method
    beacuse Clear() Method invoke the TextChanged event
    */

}

//Save As...
private void menuItemSaveAs_Click(object sender, System.EventArgs e)
{
    //dlgSaveFile is a SaveFileDialog object created from the toolbox
        //like mydoc0.txt
    dlgSaveFile.FileName = "mydoc" + m_intDocNumber.ToString() + ".txt"; 
    dlgResult = dlgSaveFile.ShowDialog();

    if(dlgResult == DialogResult.Cancel)
        return;

    try
    {
                // Saving our file name for Quick Save
        m_strFileName = dlgSaveFile.FileName; 
                //Create new StreamWriter to write the text to it
        m_sw = new StreamWriter(m_strFileName); 
        m_sw.Write (txtBody.Text);
                // don't forget to close your resources after finishing 
                // using them
        m_sw.Close(); 
        menuItemSave.Enabled = true;
                
                //increasing document number;
        m_intDocNumber++; 
        m_bModified = false; //document is saved
        this.Text = "C# Simple Notepad: " + m_strFileName;
    }
    catch(Exception err)
    {
        MessageBox.Show(err.Message,"Error",
                               MessageBoxButtons.OK,MessageBoxIcon.Error);
    }
}

private void menuItemSave_Click(object sender, System.EventArgs e)
{
    //Check if for the file name to save on the current working document or 
create new one
    if(m_strFileName == "")
    {
        //Create new one
        menuItemSaveAs_Click(sender,e);
        return;
    }
    else
    {
        //Save on the current document
        m_sw = new StreamWriter(m_strFileName);
        m_sw.Write (txtBody.Text);
        m_sw.Close();
    }
    m_bModified = false;
}

private void menuItemOpen_Click(object sender, System.EventArgs e)
{
    //Check if the current document is modified to save it
    CheckChanged(sender,e);

    // dlgOpenFile is an OpenFileDialog object
    dlgResult = dlgOpenFile.ShowDialog();
    if(dlgResult == DialogResult.Cancel)
        return;

    try
    {
                // get the file name
        m_strFileName = dlgOpenFile.FileName; 
                // open to read that file
        StreamReader sr = new StreamReader(m_strFileName); 
                //read the whole file
        txtBody.Text = sr.ReadToEnd();
        sr.Close();
        m_bModified = false;
    }
    catch(Exception err)
    {
        MessageBox.Show(err.Message,"Error",
                         MessageBoxButtons.OK,MessageBoxIcon.Error);
    }
}

Now we want to change the font and its size & style:
private void menuItemFont_Click(object sender, System.EventArgs e)
{
    //dlgFont is an FontDialog object
    dlgResult = dlgFont.ShowDialog();
    if(dlgResult == DialogResult.Cancel)
        return;

        // this property will return FontFamily selected from
        // the FontDialog
    FontFamily fmFontName = dlgFont.Font.FontFamily; 
    // this property will return float 
    // Font-size selected from the FontDialog
    float fFontSize = dlgFont.Font.Size; 
    // this property will return 
    // FontStyle selected from the FontDialog
    FontStyle fsStyle = dlgFont.Font.Style; 
    Font font;
    try
    {
        //create new font and apply it to the text in txtBody
        font = new Font(fmFontName,fFontSize,
                                    txtBody.Font.Style ^ fsStyle);
        txtBody.Font = font;
    }
    catch(ArgumentException)
    {
        return;
    }
}