更改TextBox专注于更改文本？

Question

I have been searching for hours and still can't find a solution, so how do I change the input from one text box, to another, after text has been entered. Much like a 'passcode' system, so that the user only has to enter 4 numbers and then it will move onto something else.

This is my failed attempt so far:

txtPasscode1.BecomeFirstResponder();

txtPasscode1.ValueChanged += (object sender, EventArgs e) => 
{
    txtPasscode2.BecomeFirstResponder();
};

All I need it to do, is to switch the focus from one text box to another, when text is entered. And of course vice versa when the user hits backspace. Or alternatively, any ideas as to how else this could be achieved would also be appreciated

Answer 1

why not use the TextBox.TextChanged event?

private void TextBox1_TextChanged(object sender, EventArgs e)
    {
        if (TextBox1.Text.Trim().Length == 4)
        {
            TextBox2.Focus();
        }
    }

Answer 2

This is how I managed to fix the problem, for anyone who comes across this in the future:

NSNotoficationCenter.DefaultCenter.AddObxerver(UITextField.TextFieldTextDidChangeNotification, (notification) => 
{
    //Do whatever needs to be done when the text is changed here
    if (txtFirstInput.IsFirstResponder)
    {
        txtSecondInput.BecomeFirstResponder();
    }
};

This is where I found a solution