powershell - Limiting text box entry to numbers or numpad only - no special characters -

i have small program accepts integer , converts datetime. however, try use keycode allow numbers both keyboard , numpad, , eliminate special characters , letters. code allowing shift+num enter special characters. how eliminate them being entered?

$fromdatetext.add_keydown({keydown}) $todatetext.add_keydown({keydown})  #textbox  function keydown() {     if ($fromdatetext.focused -eq $true -or $todatetext.focused -eq $true)     {         if ($_.keycode -gt 47 -and $_.keycode -lt 58 -or $_.keycode -gt 95 -and             $_.keycode -lt 106 -or $_.keycode -eq 8)         {             $_.suppresskeypress = $false          }         else         {             $_.suppresskeypress = $true           }     } } 

instead of intercepting keydown event, i'd remove non-digit character textbox every time textchanged event raised:

$todatetext.add_textchanged({     # check if text contains non-digits     if($tbox.text -match '\d'){         # if so, remove them         $tbox.text = $tbox.text -replace '\d'         # if text still has value, move cursor end of number         if($tbox.text.length -gt 0){             $tbox.focus()             $tbox.selectionstart = $tbox.text.length         }     } }) 

way easier trying infer input value key event args