Determine if an input key is a number, letter or special character

  • Thread starter Thread starter moondaddy
  • Start date Start date
M

moondaddy

Is there a simple way to determine if an input key is a number, letter or
special character? in other words, was the user inputting data and not
typing a backspace, shift, etc.

Thanks.
 
Is there a simple way to determine if an input key is a number, letter
or special character? in other words, was the user inputting data and
not typing a backspace, shift, etc.
Click to expand...

In what context?
 
Hi moondaddy,

You aren't telling is what kind of input you are talking about, but the Char
class has a set of static methods for determining what type a given character
is. For instance System.Char.IsDigit(), ...IsLetter(), ...IsControl().

If you mean input keys as in KeyEvent... there is no way to determine if a
given Key is a digit, letter or special character. You have to set up a list
of keys for each type, like D0-D9 + NumPad0-NumPad9 would mean digit input.

To ignore invalid entries in a TextBox, handle the OnKeyPress event and
check the Char value. If not valid, set KeyPressEventArgs.Cancel to true.
 
Thanks Morten,

I was referring to the keys input as in what did the user type. Sorry for
being unclear and your response was helpful.

--
(e-mail address removed)

Morten Wennevik said:
Hi moondaddy,

You aren't telling is what kind of input you are talking about, but the
Char
class has a set of static methods for determining what type a given
character
is. For instance System.Char.IsDigit(), ...IsLetter(), ...IsControl().

If you mean input keys as in KeyEvent... there is no way to determine if a
given Key is a digit, letter or special character. You have to set up a
list
of keys for each type, like D0-D9 + NumPad0-NumPad9 would mean digit
input.

To ignore invalid entries in a TextBox, handle the OnKeyPress event and
check the Char value. If not valid, set KeyPressEventArgs.Cancel to true.

--
Happy Coding!
Morten Wennevik [C# MVP]


moondaddy said:
Is there a simple way to determine if an input key is a number, letter or
special character? in other words, was the user inputting data and not
typing a backspace, shift, etc.

Thanks.
Click to expand...
Click to expand...
 
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