As I saw right there is no such event like mouseclick/click for a
groupbox.
Here's a LITERAL answer to your problem.
In the Load()
event of your Form, cast the GroupBox back to the generic Control class so you can wire up the Click() event (or a similar event from the ones available):
private void Form1_Load(object sender, EventArgs e)
{
((Control)groupBox1).Click += Ctl_Click;
}
private void Ctl_Click(object sender, EventArgs e)
{
textBox1.Focus();
}
Or with an anonymous delegate so you don't need the separate helper method:
private void Form1_Load(object sender, EventArgs e)
{
((Control)groupBox1).Click += (s2, e2) => { textBox1.Focus(); };
}