Winform-SetFocus到TabControl上usercontrol内的文本框

Question

Winform application Multiple tabs on the tabs are replicated Usercontrol

When clicking on a particular tab, I would like to setfocus to a textbox within the usercontrol. I would like to this if possible from within the tabControl_SelectedIndexChanged event.

ex:

textbox name = txtOne
txtOne resides within UserControlA
UserControlA resides within tabControl.SelectedTab.Text = "Tab2"

When I click Tab2 I'd like Focus to be set to txtone.

I've tried: (and many other things!) UserControlA.Controls["txtone"].SelectAll(); - returns object reference not set to an instance of an object

Thanks!

Answer 1

Because txtone is not an immediate child of UserControlA , UserControlA.Controls["txtone"] will return null.

You can either dig your way down the control hierarchy with control names ( UserControlA.Controls["fameFD"].Controls["txtone"] ) or simply expose txtone as a public field or property in your UserControl class. The latter would look something like this:

public TextBox TxtOne {
    get
    {
        return txtone;
    }
}

Then you could refer to the textbox from external code like this:

UserControlA.TxtOne.SelectAll();