null TextBoxes in Database Entry Form
Hello,
1. The Form has TextBoxes c1,c2,c3 receiving currency and c4 which shows the totals:
c4=c1+c2+c3
As it is now, an "Add New" Button_Click event initialize all the TextBoxes to "0.0". While this works, it places a burden on the user when entering data (he has to erase the "0.0" or might make a mistake say typing "1" without erasing "0.0" turning it into "10.0").
2. How could the c4 always show some result, starting from the initial 0.0 to c4=c1 then c4=c2 c4=c3 or c4=c1+c2 or c4=c1+c3 or c4=c1+c2+c3
Thanks,
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
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
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
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.
