Max Char in TextBox C#?

Solution 1:

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.

Solution 2:

The other answers seems to assume WinForms development.

If the case that you are doing ASP.NET development, please be aware that the MaxLength property of the System.Web.UI.WebControls.TextBox class is ignored when TextMode = Multiline. The reason is simple: the <textarea> HTML element does not provide any way to restrict the length of its contents.

You will need to do some client scripting in order to enforce a max length on a textarea.