Hello, I've been trying to create a function to calculate and return the total payment. RadioDay is a radio button with value of 7 while RadioHour is 70. Somehow I am getting InvalidCastException "Conversion from string "" to type 'Integer' is not valid." from the part where I want to convert user inputs from textbox "txtByHour" and "txtByDay" into integer value. Any help is greatly appreciated.

Function calcRate() As Integer 'calculate and return total payment for car
        Dim total, byHour, byDay As Integer

        byHour = CInt(txtByHour.Text)
        byDay = CInt(txtByDay.Text)

        If byHour > 24 Then 'making sure the user does not input more than 24 hours
            MessageBox.Show("Please put a number between 1 to 24")
        End If

        If RadioDay.Checked Then

            total = byHour * 7
        ElseIf RadioHour.Checked Then

            total = byDay * 70
        End If

        Return total

    End Function

Recommended Answers

All 4 Replies

Maybe use this:

        byHour = CInt(Val(Trim(txtByhour.Text)))
        byDay = CInt(Val(Trim(txtByday.Text)))
commented: It works +0

Thank you very much it's working perfectly now

Thank you all , I just learnt something new today =)

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, learning, and sharing knowledge.