How to generate random number with String + integer value? [duplicate]

This question already has an answer here:

• How can I generate random alphanumeric strings in C#? 23 answers

Random random = new Random();
            textBox1.Text = "" + random.Next(0, 9) + random.Next(0, 9) + random.Next(0, 9) + random.Next(0, 9)+ "-" + random.Next(0, 9) + random.Next(0, 9) + random.Next(0, 9) + random.Next(0, 9);

This is generating random number with integer. but I want to generate random number with String value also.