form validation

[dky1e]

Hi,

I have a set of text boxes and I want to test for the type of the input, whether it's a string, decimal or integer.

If any of those do not match I want to display an error message.

How to check the strings in text boxes if they satisfy the format?

How to display an alert window?

Thank you for your help!

[vszilard]

1) There is a MessageBox Class in .net which provide you an alert window as customisable as you want.

ex.
MessageBox.Show("You must enter a name.", "Name Entry Error",
MessageBoxButtons.OK, MessageBoxIcon.Exclamation);

Check the sdk documentation for mor information...

2) There is a Type Class in .net which provide you all the method you need to get a type to check a type...

GetType method..

Check the sdk documentation for mor information...

[dky1e]

The problem with get type is that input to text boxes are strings.

[V. Lorenzo]

Hi:

For doing validation stuff you may include the System.Text.RegularExpression namespace to your project and use the classes on it.

Take a look at http://windows.oreilly.com/news/csharp_0101.html.

You may also take a look at http://regexlib.com/Default.aspx., you will find there a lot of regular expressions.

VictorL

[Arild Fines]

You could always just try converting them to your desired format:

try
{
   myDecimal = Decimal.Parse( myTextBox.Text );
}
catch( FormatException ex )
{
   MessageBox.Show( "You entered a bad number,  stupid!", "Bleh!" );
}