null TextBoxes in Database Entry Form

null TextBoxes in Database Entry Form

• Al33327

  Hi Spotty,

  Thanks for your time. The EntryForm is the front-end to a Database and a somewhat more complicated that it was posted originally. (It has other TextBoxes like Date, ID number and Location, UnitPrice).

  As it is now, the "AddNewRecord" Button loads a fresh EntryForm. This event also initialize 2 set of 3 TextBoxes with "0.0" .  

  Three calculations are performed. Ctotal=C1+C2+C3,   D1=C1*UnitPrice,   Etotal=D1+D2+D3.  All of them are declared as Single.

  The user Tabs through the TextBoxes and enters data. Ctotal_OnFocus on the final performs C1+C2+C3 and Etotal_OnFocus  D1+D2+D3.

  So far so good. But what if, the user made a mistake and goes back to any of the TextBoxes. Well, the cursor stucks in the field unless the user type a number. For this reason, every TextBox have a TextBox_MouseEnter event which rewrites "0.0" into the field of concern.

  To do:  As it is now, the fields Etotal or Ctotal would no update on the fly, initilazation is ugly ( C1TextBox.Text = "0.0",... C3TextBox.Text = "0.0"; D1TextBoxText="0.0" )ad nauseam. Neither are the variable declarations are charming.

  I hope hearing from you,

  P.S. --- Thanks again. This sub() thing looks good. It is new for this newbie - so I have to sleep over it.

    

  
  
  

• polymorphicx

  Hi,

  Set the textboxes to be blank.

  Then the sum is>>

  Dim result As Double

  If c1.text="" then

  c1.text="0.0"

  EndIf

  If c2.text="" then

  c2.text="0.0"

  EndIf

  If c3.text="" then

  c3.text="0.0"

  EndIf

  result=CDBL(c1.text + c2.text + c3.text)

  c4.text=CSTR(result)

  That should do it. :-)

  Regards,

  S_DS

  
  
  

• totty3478

  Here's an example - basically, the getfocus and lostfocus events are used to wipe out the textbox, and restore the 0.0 in case nothing is entered. A try/catch is used in case the value in the textbox isn't convertible to a decimal, and the textchanged event is used to update the results in the other textbox:

  Public Class Form1

  Private Sub TextBox1_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.GotFocus
  If TextBox1.Text = "0.0" Then TextBox1.Text = ""
  End Sub

  Private Sub TextBox1_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.LostFocus
  If TextBox1.Text = "" Then TextBox1.Text = "0.0"
  End Sub

  Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
  Try
  TextBox2.Text = CDec(TextBox1.Text) + CDec(TextBox1.Text)
  Catch ex As Exception
  End Try

  End Sub

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
  TextBox1.Text = "0.0"
  End Sub
  End Class

  
  
  

• Al-Arabi

  You could do this prior to calculation

  
  Public Class Form1

  Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
          resetdefaultvalues()
      End Sub

  
      Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
          resetdefaultvalues() '//Reset Default value for textboxes

          Dim sglAnswer As Single = 0
          For Each t As Control In Me.Controls
              If TypeOf (t) Is TextBox And t.Name.StartsWith("TextBox") Then
                  sglAnswer = sglAnswer & CType(t.Text, Single)
              End If
          Next

          Me.txtAnswer.Text = sglAnswer.ToString
      End Sub

      Sub resetdefaultvalues()
          For Each t As Control In Me.Controls
              If TypeOf (t) Is TextBox And t.Name.StartsWith("TextBox") Then
                  If t.Text.Length = 0 Then t.Text = "0.0"
              End If
          Next
      End Sub
  End Class

   

   

  Or do it when the textbox loses focus

  
  
  Public Class Form1
      Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
          Recalc()
      End Sub

      Private Sub TextBox1_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.LostFocus, TextBox2.LostFocus
          If CType(sender, TextBox).Text.Length = 0 Then
              CType(sender, TextBox).Text = "0.0"
          End If
          Recalc()
      End Sub

  
      Sub Recalc()
          For Each t As Control In Me.Controls
              If TypeOf (t) Is TextBox And t.Name.StartsWith("TextBox") Then
                  If t.Text.Length = 0 Then t.Text = "0.0"
              End If
          Next

  
          Dim sglAnswer As Single = 0
          For Each t As Control In Me.Controls
              If TypeOf (t) Is TextBox And t.Name.StartsWith("TextBox") Then
                  sglAnswer = sglAnswer & CType(t.Text, Single)
              End If
          Next

          Me.txtAnswer.Text = sglAnswer.ToString
      End Sub

      Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
          Recalc()
      End Sub
  End Class

  
   

  
  
   

  
  
• null TextBoxes in Database Entry Form