How to validate UserName that should start with characters followed by underscore and then followed by characters?

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How to validate UserName that should start with characters followed by underscore and then followed by characters??

Thanks...

Posted 23-Sep-12 19:52pm

Updated 23-Sep-12 19:53pm

v2

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D-Kishore 24-Sep-12 1:55am

Kindly give me one example(output)

2 solutions

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Santhosh Kumar Jayaraman · Answer 1 · 2012-09-23T20:03:00

try this

C#

public bool IsAlphaNumericWithUnderscore(string input)
{
    return Regex.IsMatch(input, "^[a-zA-Z0-9_]+$");
}

or

C#

bool result = input.All(c=>Char.IsLetterOrDigit(c) || c=='_');

Posted 23-Sep-12 20:03pm

Updated 23-Sep-12 20:04pm

v3

Sushil Mate · Answer 2 · 2012-09-23T20:17:00

You can use the regular expression for this. something like this.

C#

var regExp = new Regex("[a-zA-Z]+_[a-zA-Z]+");
Match match = regExp.Match(UserName);
if (!match.Success)
{
  //Invalidate.
  //return
}

Posted 23-Sep-12 20:17pm

Updated 23-Sep-12 20:18pm

v2