R – Silverlight Textbox

Two options:

1. Use a NumericUpDown instead. NumericUpDown does the filtering for you, which is nice. Of course it also gives your users the ability to hit the up and down arrows on the keyboard to increment and decrement the current value.

2. Handle the appropriate keyboard events to prevent anything but numeric input. I've had success with this two event handlers on a standard TextBox:

   private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
   {
       if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) &&
           (e.KeyChar != '.'))
       {
               e.Handled = true;
       }
   
       // only allow one decimal point
       if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1))
       {
           e.Handled = true;
       }
   }
   

You can remove the check for '.' (and the subsequent check for more than one '.') if your TextBox shouldn't allow decimal places. You could also add a check for '-' if your TextBox should allow negative values.

If you want to limit the user for number of digit, use: textBox1.MaxLength = 2; // this will allow the user to enter only 2 digits

If you just want to prevent the 'enter' key from creating a newline, you can use preventDefault to block it.

$("textarea").keypress(function (event) {
    if (event.which == '13') {
        event.preventDefault();
    }
});

fiddle

If you really want enter pressed anywhere in the input to go to the end of the input, you can also reset the value which will always put the cursor at the end of the input:

$("textarea").keypress(function (event) {
    if (event.which == '13') {
        var val = $(this).val();       
        $(this).val('');
        $(this).val(val);
        event.preventDefault();
    }
});