Regular Expression Asp.Net MVC

Question

I was trying to get a user name validations where the following texts are valid,

• Test
• Test2
• Tes2
• Test123
• 123Test
• 1234
• Test_56
• test-6ty

But not the following

• Tes (Min Length)
• Test@123 (Special char)

I added following annotations in Model, though does't seem to be working for the correct texts too. Keep getting the error message.

[RegularExpression(@"^[a-zA-Z0-9\-_]$", ErrorMessage = "Only alphanumeric, hyphen and underscores are allowed for User name.")]
[StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 4)]

Answer 1

From your examples it looks like this regex can be suitable for you:

@"^[a-zA-Z0-9_-]{4,10}$"

{4,10} sets minimum length of input to 4 and max length to 10. Change it whatever limits you want to keep.