Look at the MaxLength
property of the TextBox
– it stores the maximum number of characters the control can take; as per the documentation, it is changeable. Usually the default is big enough, though. (Although I imagine that since you’re asing the question, it may not be!)
From the docs, you can see that the maximum value for MaxLength
is 2147483646. This is, of course, limited by the memory of the target machine.