Question

I have written three different Private Sub functions, all of which do the same thing Private Sub txt_noRooms_KeyPress and Private Sub txt_length_KeyPress ensure that the user can only type in values 1 to 9 into the referenced text fields whereas Private Sub txt_studentNo_KeyPress allows the user to type in values 0 to 9 into the referenced text field.

Is there any way I can merge these three functions and have them still support the referenced cells and maintain the same conditions? I want to do this for the purpose of making the code more efficient.

Private Sub txt_noRooms_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
' Restrict entry to txt_noRooms
Select Case KeyAscii
    Case Asc("1") To Asc("9")
    Case Asc("-")
        If InStr(1, Me.txt_noRooms.Text, "-") > 0 Or Me.txt_noRooms.SelStart > 0 Then
            KeyAscii = 0
        End If
    Case Asc(".")
        If InStr(1, Me.txt_noRooms.Text, ".") > 0 Then
            KeyAscii = 0
        End If
    Case Else
        KeyAscii = 0
End Select
End Sub


Private Sub txt_length_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)   
' Restrict entry to txt_length
Select Case KeyAscii
    Case Asc("1") To Asc("9")
    Case Asc("-")
        If InStr(1, Me.txt_length.Text, "-") > 0 Or Me.txt_length.SelStart > 0 Then
            KeyAscii = 0
        End If
    Case Asc(".")
        If InStr(1, Me.txt_length.Text, ".") > 0 Then
            KeyAscii = 0
        End If
    Case Else
        KeyAscii = 0
End Select
End Sub


Private Sub txt_studentNo_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
' Restrict entry to txt_studentNo
Select Case KeyAscii
    Case Asc("0") To Asc("9")
    Case Asc("-")
        If InStr(1, Me.txt_studentNo.Text, "-") > 0 Or Me.txt_studentNo.SelStart > 0 Then
            KeyAscii = 0
        End If
    Case Asc(".")
        If InStr(1, Me.txt_studentNo.Text, ".") > 0 Then
            KeyAscii = 0
        End If
    Case Else
        KeyAscii = 0
End Select
End Sub

Answer 1

You can set one private function and call it from each keypress:

  Private Sub txt_noRooms_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
' Restrict entry to txt_noRooms
If bclearfield(CLng(KeyAscii), Me.txt_noRooms.Text, Me.txt_noRooms.selStart,"1")  Then KeyAscii = 0
End Sub


Private Sub txt_length_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
' Restrict entry to txt_length
If bclearfield(CLng(KeyAscii), Me.txt_length.Text, Me.txt_length.selStart,"1") Then KeyAscii = 0
End Sub

Private Sub txt_studentNo_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
' Restrict entry to txt_studentNo
If bclearfield(CLng(KeyAscii), Me.txt_studentNo.Text, Me.txt_studentNo.selStart,"0") Then KeyAscii = 0
End Sub

Private Function bClearField(KeyAscii As Long, sText As String, lSelStart As Long,sLowLimit as string) As boolean

bClearField=false
Select Case KeyAscii
    Case Asc(sLowLimit ) To Asc("9")
    Case Asc("-")
        If InStr(1, sText, "-") > 0 Or lSelStart > 0 Then
            bClearField=true
        End If
    Case Asc(".")
        If InStr(1, sText, ".") > 0 Then
            bClearField=true
        End If
    Case Else
        bClearField=true
End Select

End Function