[C#]Extract Integer from a Textbox

Hi all,

How can I convert the text in a textbox to an integer?

Can I use something like this?:

[COLOR=Blue]
[/COLOR][COLOR=Blue]int[/COLOR] Integer; 
Integer = Convert.ToInt32(textBox1.Text); 
Integer = [COLOR=Blue]int[/COLOR].Parse(textBox1.Text);

Code (markup):

And to menage not expected values (like char o string) is correct using try{} and catch{}?

Thanks to all

 

You can test for the length of the string and not convert if the length is 0. (A string with just char 0 is 0 length.) You could use a try/catch block, but that generates more code than just a simple length test. (The "value" of non-numeric text will be 0.)

 

With the lenght I can control if the string is empty (0) or not (<0), but I can't control which are the types of data in input (int,char) and I can't menage the error.

 

yes you can do that.

 

But you can add if statement to check the type of data and convert types by casting.

 

You can validate both Windows Forms and ASP.Net controls input values. If you just want to check if a string contains an integer value here is a MSDN How-to article:How to:

Determine Whether a String Represents a Numeric Value (C# Programming Guide):

http://msdn.microsoft.com/en-us/library/bb384043.aspx

Here is the example from the article:

int i = 0; 
  string s = "108"; 
 bool result = int.TryParse(s, out i); //i now = 108

Code (markup):

 

Try/catch is indeed the way to handle it for text values that do not fit -- what you want to intercept is formatException.

See the example on the MSDN page for toInt32:
http://msdn.microsoft.com/en-us/library/sf1aw27b.aspx

or parse:
http://msdn.microsoft.com/en-us/library/b3h1hf19.aspx

I would use toInt32 so you can dictate the result size.

try {
  int Integer;
  Integer = Convert.ToInt32(textBox1.Text);
  // do whatever it is your doing with the integer here
} catch (FormatException) {
  // resend form with error as it's got a non-integer value
}

Code (markup):