Only numeric value in textbox

  • Thread starter Thread starter Guest
  • Start date Start date
If you are only going to do this in one place then you can do something like
this:

private void textBox1_KeyPress(object sender,
System.Windows.Forms.KeyPressEventArgs e)

{

e.Handled = !char.IsDigit(e.KeyChar);

}


Keep in mind the above code doesn't acct. for BackSpace, ., -, +, e

--
Thanks
Wayne Sepega
Jacksonville, Fl

Enterprise Library Configuration Console Module Generator
http://workspaces.gotdotnet.com/elccmg

"When a man sits with a pretty girl for an hour, it seems like a minute. But
let him sit on a hot stove for a minute and it's longer than any hour.
That's relativity." - Albert Einstein
 
The following code cam be used to validate the Text that has been input.
try
{
float myNumber = Float.Parse(txtBox1.text);
//Mynumber will have the value
}
catch
{
MessageBox.show("Invalid Number");
}
 
ZS said:
The following code cam be used to validate the Text that has been input.
try
{
float myNumber = Float.Parse(txtBox1.text);
//Mynumber will have the value
}
catch
{
MessageBox.show("Invalid Number");
}
Click to expand...

IMO, it's better GUI design to not let the user input the invalid data in
the first place. Their ability to input invalid data could introduce
confusion.

This should work:

void tb_KeyPress(object sender, KeyPressEventArgs e)
{
e.Handled = !Char.IsDigit(e.KeyChar) && e.KeyChar != '\b';
}
 
I don't know if this helps, but I found a pertinent article on the Web (don't
remember where) which had the following two methods in it. I've implemented
them and they work great!


// Tests whether the input string is a whole number - ie. 0, 1, 2, ...
public static bool IsWholeNumber(string txt)
{
if (txt == null)
txt = "";

Regex objNotWholePattern=new Regex("[^0-9]");
return !objNotWholePattern.IsMatch(txt);
}


// Will return 'txt' as is if it's a number; otherwise will return a
null string
public static string NumericOnly(string txt)
{
if (IsWholeNumber(txt))
return txt;
else
return "";
}
 
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