Using an If statement when comparing two variables

[ABOU]

I am trying to assign validation to a text box, SexTextBox

I wish to allow only M or F to be inserted, if the user inserts anything else i want it to throw up an error provider.

So far i have come up with:

If Me.SexTextBox.Text <> "M" Then
            Me.ErrorProvider1.SetError(SexTextBox, "Enter M or F only!")
            Me.SexTextBox.Text = ""
            Me.SexTextBox.Focus()
        Else
            Me.ErrorProvider1.SetError(SexTextBox, "")

        End If

This will work to prevent all but M being entered.

I thought that if i wanted to allow M and F creating the following code would work:

If Me.SexTextBox.Text = "M" Then
            Me.ErrorProvider1.SetError(SexTextBox, "")


        ElseIf Me.SexTextBox.Text = "F" Then
            Me.ErrorProvider1.SetError(SexTextBox, "")

        Else

            Me.ErrorProvider1.SetError(SexTextBox, "Enter M or F only!")
            Me.SexTextBox.Text = ""
            Me.SexTextBox.Focus()

        End If

It appears to prevent incorrect entry but no error provider is displayed.


Found this forum post seems to explain it:

http://www.developerfusion.co.uk/forums/p/36104/149689/#149689

 

[jshultz]

Why don't you just prevent them from being able to enter anything but "M" or "F"? See this thread:
http://www.vbdotnetforums.com/showthread.php?t=26015

 

[JuggaloBrotha]

This sounds like a web form, but I could be wrong.

Why don't you use a ComboBox. Let them select the word "Male" or "Female" with "Male" having a value of "M" and "Female" has a value of "F".

But this code here should do the trick for ya:

        If Me.SexTextBox.Text <> "M" AndAlso Me.SexTextBox.Text <> "F" Then
            Me.ErrorProvider1.SetError(SexTextBox, "Enter M or F only!")
            Me.SexTextBox.Text = ""
            Me.SexTextBox.Focus()
        Else
            Me.ErrorProvider1.SetError(SexTextBox, "")
        End If

 

[ABOU]

IT hadnt occured to me to use a combo box, as it is for an assignemnt i wanted to make use of as many components as i can.

I have never come across the

AndAlso

expression, was racking my brains over that today.

 

[JuggaloBrotha]

AndAlso is new to VB .Net and is actually better to use in the sense that AndAlso doesn't evaluate both cases all the time, if the first case fails VB never bothers with the second (third, fourth, etc) because the whole thing will be false if any one of them are false.

This speeds things up quite a bit, especially in the middle of loops.

 

[InertiaM]

I know it may be obvious, but I'll state it anyway - there's also "OrElse"

 

[JuggaloBrotha]

I know it may be obvious, but I'll state it anyway - there's also "OrElse"

Yes there is