Validating Event VB.net

Alright, I have read and searched but I dont understand what a validating event is and how I use it for this program. Basically, I am trying to make sure that text in 3 dif textboxes is btween 0 and 100 and if its not, I need to change the forecolor to red . Can someone let me know if I am on the right track? My prob. right now is changing the forecolor.
Thanks
Jen

VB Code:

Private mblngrade As Boolean
    Private Sub CalcButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CalcButton.Click
        'declare variables
        Dim decTest1, decTest2, decTest3, decAverage As Decimal
        Dim strID, strName, strGrade As String
        Dim blnGrade As Boolean
        'assign value to variables
        decTest1 = Val(Me.Test1TextBox.Text)
        decTest2 = Val(Me.Test2TextBox.Text)
        decTest3 = Val(Me.Test3TextBox.Text)
 
        strID = Me.IDTextBox.Text
        strName = Me.StudentTextBox.Text
        mblnGrade = ValidGrade(decTest1, decTest2, decTest3)
        decAverage = (decTest1 + decTest2 + decTest3) / 3
        'display Grade
 
        If blnGrade = True Then
            Me.AverageDisplay.Text = decAverage
        Else
            MessageBox.Show("This value must be between 0 and 100.", "Average", _
            MessageBoxButtons.OK, MessageBoxIcon.Information)
        End If
    End Sub
 
    Function ValidGrade(ByRef dec1 As Decimal, ByRef dec2 As Decimal, ByRef dec3 As Decimal) As Boolean
        'delcare varaible for boolean value
        Dim blnGrade As Boolean
 
        If dec1 >= 0 And dec1 <= 100 Then
            If dec2 >= 0 And dec2 <= 100 Then
                If dec3 >= 0 And dec3 <= 100 Then
                    Return True
                Else : Return False
                End If
            End If
        End If
 
    End Function
 
 
 
 
 
    Private Sub ClearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ClearButton.Click
        'clear the textboxes
        Me.StudentTextBox.Text = ""
        Me.IDTextBox.Text = ""
        Me.Test1TextBox.Text = ""
        Me.Test2TextBox.Text = ""
        Me.Test3TextBox.Text = ""
        Me.AverageDisplay.Text = ""
        Me.GradeLabel.Text = ""
    End Sub
   
    'Validate TextBoxes and change forecolor to red if data is invalid
    Private Sub Test1TextBox_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles Test1TextBox.Validating, Test2TextBox.Validating, _
    Test3TextBox.Validating
        If mblngrade = True Then
            e.Cancel = False
        End If
    End Sub
 
    Private Sub ExitButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitButton.Click
        Me.Close()
    End Sub
End Class

Hi,

"Alright, I have read and searched but I dont understand what a validating event is and how I use it for this program"

You are already using a validating event in this post AND in your previous post.

i.e.

" If blnGrade = True Then
Me.AverageDisplay.Text = decAverage
Else
MessageBox.Show("This value must be between 0 and 100.", "Average", _
MessageBoxButtons.OK, MessageBoxIcon.Information)
End If"

You are simply checking the value of the entries made and ensuring they are between 0 and 100 - i.e. You are trying to VALIDATE those entries. (Even though you have failed to do so - see below)




In your following code

" Function ValidGrade(ByRef dec1 As Decimal, ByRef dec2 As Decimal, ByRef dec3 As Decimal) As Boolean
'delcare varaible for boolean value
Dim blnGrade As Boolean

If dec1 >= 0 And dec1 <= 100 Then
If dec2 >= 0 And dec2 <= 100 Then
If dec3 >= 0 And dec3 <= 100 Then
Return True
Else : Return False
End If
End If
End If

End Function"

You do not need to declare blnGrade as Boolean. The function returns the function result under the name of the function. In your case blnGrade (please note the possible mis-spelling in your code as you have not declared mblnGrade) will be set to the result of the function ValidGrade. You have, in fact, tried to declare blnGrade in two separate subs!!

Also, the function will only return False if dec3 is false. If either dec1 or dec2 are incorrect, the function will show them as correct.

Have a look at the following thread and let us know if it solves your problem:

http://www.vbforums.com/showthread.p...&highlight=red

Hi, thanks for the reply!

This function returns a message box stating an error for dec1, dec2, and dec 3 (any of them) That part works fine.

VB Code:

Function ValidGrade(ByRef dec1 As Decimal, ByRef dec2 As Decimal, ByRef dec3 As Decimal) As Boolean
        If dec1 >= 0 And dec1 <= 100 Then
            If dec2 >= 0 And dec2 <= 100 Then
                If dec3 >= 0 And dec3 <= 100 Then
                    Return True
                Else : Return False
                End If
            End If
        End If

What I dont understand is ... the validating event.... and changing the forecolor to red when the function returns a false value to the click event sub procedure.
Thanks
Jen

Hi,

"This function returns a message box stating an error for dec1, dec2, and dec 3 (any of them) That part works fine."


When dec1 is less than 0, the function code you posted exits on the line

If dec1 >= 0 And dec1 <= 100 Then

with the result that Return False does NOT get executed. OIf you are getting a False result for dec1 or dec2, then your other code must be producing it.

If you want to use that code then try

VB Code:

Function ValidGrade(ByRef dec1 As Decimal, ByRef dec2 As Decimal, ByRef dec3 As Decimal) As Boolean
     ValidGrade=False
        If dec1 >= 0 And dec1 <= 100 Then
            If dec2 >= 0 And dec2 <= 100 Then
                If dec3 >= 0 And dec3 <= 100 Then
                    Return True
                 End If
            End If
        End If
 
    End Function

Now, unless all three are OK the function will return False.


"What I dont understand is ... the validating event.... and changing the forecolor to red when the function returns a false value to the click event sub procedure."

I covered this fully. Which part of my response did you not understand?

Should my Function Procedure send the value back to the CalcButton Click event procedure or should I send it somewhere else?

I am very new at this and this program is obviously way beyond my skill level.. but I am just trying to learn as much as I can.
This is my revised code.. not that its any better

jen

VB Code:

'declare form level variables
    Private mdecTest1, mdecTest2, mdecTest3, mdecAverage As Decimal
    Private mstrID, mstrName, mstrGrade As String
    Private mblnGrade, mblnGrade2, mblnGrade3 As Boolean
 
    Private Sub CalcButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CalcButton.Click
        'assign value to variables
        mdecTest1 = Val(Me.Test1TextBox.Text)
        mdecTest2 = Val(Me.Test2TextBox.Text)
        mdecTest3 = Val(Me.Test3TextBox.Text)
        mstrID = Me.IDTextBox.Text
        mstrName = Me.StudentTextBox.Text
        mblnGrade = ValidGrade(mdecTest1)
        mblnGrade2 = ValidGrade2(mdecTest2)
        mblnGrade3 = ValidGrade3(mdecTest3)
        mdecAverage = (mdecTest1 + mdecTest2 + mdecTest3) / 3
 
        'display Grade
        If mblnGrade = True Then
            Me.AverageDisplay.Text = mdecAverage
            Test1TextBox.ForeColor = Color.Black
        Else
            Test1TextBox.ForeColor = Color.Red
            Me.AverageDisplay.Text = ""
        End If
 
        If mblnGrade2 = True Then
            Me.AverageDisplay.Text = mdecAverage
            Test2TextBox.ForeColor = Color.Black
        Else
            Test2TextBox.ForeColor = Color.Red
            Me.AverageDisplay.Text = ""
        End If
 
        If mblnGrade3 = True Then
            Me.AverageDisplay.Text = mdecAverage
            Test3TextBox.ForeColor = Color.Black
        Else
            Test3TextBox.ForeColor = Color.Red()
            Me.AverageDisplay.Text = ""
        End If
 
    End Sub
 
    Function ValidGrade(ByRef dec1 As Decimal) As Boolean
        If dec1 >= 0 And dec1 <= 100 Then
            Return True
        Else
            Return False
        End If
    End Function
 
    Function ValidGrade2(ByRef dec2 As Decimal) As Boolean
        If dec2 >= 0 And dec2 <= 100 Then
            Return True
        Else
            Return False
        End If
    End Function
 
    Function ValidGrade3(ByRef dec3 As Decimal) As Boolean
        If dec3 >= 0 And dec3 <= 100 Then
            Return True
        Else
            Return False
        End If
    End Function
 
    'clear the textboxes and send the focus to studenttextbox
    Private Sub ClearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ClearButton.Click
        Me.StudentTextBox.Text = ""
        Me.IDTextBox.Text = ""
        Me.Test1TextBox.Text = ""
        Me.Test2TextBox.Text = ""
        Me.Test3TextBox.Text = ""
        Me.AverageDisplay.Text = ""
        Me.GradeLabel.Text = ""
        Me.StudentTextBox.Focus()
    End Sub
 
    'code the exit button
    Private Sub ExitButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitButton.Click
        Me.Close()
    End Sub

Hi,

From your posts, you seem to be ignoring my replies/questions.
The thread I quoted covers exactly the same problem as you are raising. Have you looked at it? If you have, you should be using something like:

VB Code:

Private Sub Test_Text_Validity(objTXT as TextBox)
   if val(objTXT.Text)<=0 then objTXT.Forecolor=Color.Red
end sub
 
Private Sub Test1TextBox_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt1.LostFocus
    Test_Text_Validity(Test1TextBox)
 End Sub
 
Private Sub Test2TextBox_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt1.LostFocus
    Test_Text_Validity(Test2TextBox)
 End Sub
 
Private Sub Test3TextBox_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt1.LostFocus
    Test_Text_Validity(Test3TextBox)
 End Sub
 
(When you learn about Overloading,  you can do away with two of the above Subs)
 
 
    Private Sub CalcButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim strMessage as String="Invalid Value in "
        select case true
            case val(Test1TextBox.text)<=0
                strMessage=strMessage & "Test1TextBox"
            case val(Test2TextBox.text)<=0
                strMessage=strMessage & "Test2TextBox"
            case val(Test3TextBox.text)<=0
                strMessage=strMessage & "Test3TextBox"
            case else
                mstrName = Me.StudentTextBox.Text
 AverageDisplay.Text=Str(= (val(Test1TextBox.text) +val(Test2TextBox.text)+ val(Test1TextBox.text)) / 3)
 
                Exit Sub
         End select
         Messagebox.show(strMessage)
        End Sub
 
Private Sub ClearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ClearButton.Click
        StudentTextBox.Text = ""
        IDTextBox.Text = ""
        Test1TextBox.Text = ""
        Test1TextBox.ForeColor=Color.Black
        Test2TextBox.Text = ""
        Test2TextBox.ForeColor=Color.Black
        Test3TextBox.Text = ""
        Test3TextBox.ForeColor=Color.Black
        AverageDisplay.Text = ""
        GradeLabel.Text = ""
        StudentTextBox.Focus()
    End Sub

I have not checked this for bugs.

I have NOT ignored your posts. I am not looking for someone to write the code for me, I just wanted some help understanding the whole concept. Thanks for your help, but nevermind, I will just figure it out myself.

Thanks

Jennifer

Hi jenbug,

I did not intend to offend. Please accept my apologies. I was just trying to determine exactly what it was that you did not understand.