Msdn docs only tell you how to databind using the designer. I too had a bit of a hard time learning this simple thing a few years earlier :)
You're manually loading data & binding - here's an example of manually binding to a textbox placed within a repeater
Assuming TextBox name is TextBox1, DataTable's name is questions, Repeater's name is DataRepeater1 & columns in your table like "Column1", "Column2" etc
TextBox1.DataBindings.Add("Text", questions, "Column1");
DataRepeater.DataSource=questions;
"Text" is the property of the control you're binding to - you can bind to other properties like "Tag", "Visible" etc. Hope you get the idea.
Here's another checkbox binding example
CheckBox1.DataBindings.Add("Checked",questions","Column2");
Add a repeater & a textbox within it & run this code to test if you want
DataTable dt = new DataTable()
dt.Columns.Add("c1");
dt.Rows.Add("1");
dt.Rows.Add("2");
dt.Rows.Add("3");
dt.Rows.Add("4");
dt.Rows.Add("5");
TextBox1.DataBindings.Add("Text", dt, "c1");
DataRepeater1.DataSource = dt;