In this little tutorial, you will learn to make a tab system like Notepad++, Charny NotePad, Firefox, etc.

First of all, I'll explain what we will do. We will make a notepad application with a tab system.

1) Open your IDE and start a new windows forms application project.

2) Add these controls to the form :

Control
 Name
 Properties
TabControl
 tabControl
 Set 'Dock' to 'Fill'
MenuStrip
 menuStrip
 Don't change anything

Now, you will add two ToolStripMenuItem to menuStrip, 'File' and 'Edit'.

Screenshot0.png



After, add one ToolStripMenuItem in 'File', his text will be 'New' and his name will be menuNew.

Screenshot1.png


Add four ToolStripMenuItem and a ToolStripSeparator to the 'Edit' menu :

Text
 Name
Cut
 menuCut
Copy
 menuCopy
Paste
 menuPaste

 toolStripSeparator1
Select All
 menuSelectAll

Screenshot2.png


3) Add a Click event handler to menuNew :

private void menuNew_Click(object sender, EventArgs e)
{
TabPage tp = new TabPage("New Document");
RichTextBox rtb = new RichTextBox();
rtb.Dock = DockStyle.Fill;
tp.Controls.Add(rtb);
tabControl.TabPages.Add(tp);
}

You can try the program now. When you press on 'New' it creates a new TabPage with a RichTextBox in tabControl. It works, but if you have many tab pages, how could you execute actions to the selected RichTextBox?

4) Add this method in your code :

private RichTextBox GetActiveEditor()
{
TabPage tp = tabControl.SelectedTab;
RichTextBox rtb = null;
if (tp != null)
{
rtb = tp.Controls[0] as RichTextBox;
}
return rtb;
}

So, this method retreives the first control of the selected tab. The first control is the RichTextBox.

5) Now, we will add a Click event handler on each ToolStripMenuItem of the 'Edit' menu.

menuCut:

private void menuCut_Click(object sender, EventArgs e)
{
GetActiveEditor().Cut();
}

menuCopy:

private void menuCopy_Click(object sender, EventArgs e)
{
GetActiveEditor().Copy();
}

menuPaste:

private void menuPaste_Click(object sender, EventArgs e)
{
GetActiveEditor().Paste();
}

menuSelectAll:

private void menuSelectAll_Click(object sender, EventArgs e)
{
GetActiveEditor().SelectAll();
}