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Validate Textbox

vishnu vardhan

Hello,

Validate text box that accept only Digits, Letters and First charecter should be Capital P only and the Maximum length of Textbox should be 6 charecters.

i know the code to accept digits and letters and Max length but i don't know how to set First charecter of Text box to capital P. pls some one provide me code ..

Thanks

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
The easiest way is to use a regular expression:

using System.Text.RegularExpressions;

// ....

string regExp = "^P[a-zA-Z0-9]{5}$";

if (!Regex.IsMatch(textBox1.Text, regExp))
{
MessageBox.Show("Invalid input. Please amend");
textBox1.Focus();
return;
}

The above assumes the text will be exactly 6 characters long.
If it could be between 2 and 6 characters, then use instead:

string regExp = "^P[a-zA-Z0-9]{1,5}$";