c# - Assigning event TextChanged to all textboxes in Form

Question

Hello I was wondering how can I keep an eye on all textboxes in Form whether in any of them was changed value. I saw some code here

private void Form1_Load(object sender, EventArgs e)
{
    foreach (Control ctrl in this.Controls)
    {
        if (ctrl is TextBox)
        {
            TextBox tb = (TextBox)ctrl;
            tb.TextChanged += new EventHandler(tb_TextChanged);
        }
    }
}

void tb_TextChanged(object sender, EventArgs e)
{
    TextBox tb = (TextBox)sender;
    tb.Tag = "CHANGED"; // or whatever
}

And a guy who wrote this code says that "it can't be assigned to textboxes in Panels and Grouboxes".

So my question is as I have almost every textbox in groubox or panel, how can I see whether change was made for textboxes in panels or groupbox?

Answer 1

You can make your method recursive:

private void Form1_Load(object sender, EventArgs e)
{
    Assign(this);
}

void Assign(Control control)
{
    foreach (Control ctrl in control.Controls)
    {
        if (ctrl is TextBox)
        {
            TextBox tb = (TextBox)ctrl;
            tb.TextChanged += new EventHandler(tb_TextChanged);
        }
        else
        {
            Assign(ctrl);
        }
    }
}

void tb_TextChanged(object sender, EventArgs e)
{
    TextBox tb = (TextBox)sender;
    tb.Tag = "CHANGED"; // or whatever
}

Just find a better name for the method instead of Assign.