how to substract value if criteria mets?

Question

hello to all,

can any one help me for this

i have a five text boxes in visual basic 2010 form

code to fill textbox1:

 Private Sub txtcatgen_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtcatgen.TextChanged
        If txtcatgen.Text = "GENERALMALE" Then
            txtba1fees.Text = "510"
        End If
        If txtcatgen.Text = "GENERALFEMALE" Then
            txtba1fees.Text = "495"
        End If
        If txtcatgen.Text = "OBCMALE" Then
            txtba1fees.Text = "510"
        End If
        If txtcatgen.Text = "OBCFEMALE" Then
            txtba1fees.Text = "495"
        End If
        If txtcatgen.Text = "SCMALE" Then
            txtba1fees.Text = "0"
        End If
        If txtcatgen.Text = "SCFEMALE" Then
            txtba1fees.Text = "0"
        End If
        If txtcatgen.Text = "STMALE" Then
            txtba1fees.Text = "0"
        End If
        If txtcatgen.Text = "STFEMALE" Then
            txtba1fees.Text = "0"
        End If
    End Sub

in the textbox2 change the code are:

Private Sub txtba1fees_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtba1fees.TextChanged

        If txtcatgen.Text = "GENERALMALE" Then
            txtba1fees1.Text = txtba1fees.Text - "495"
        ElseIf txtcatgen.Text = "GENERALFEMALE" Then
            txtba1fees1.Text = txtba1fees.Text - "495"
        ElseIf txtcatgen.Text = "OBCMALE" Then
            txtba1fees1.Text = txtba1fees.Text - "495"
        ElseIf txtcatgen.Text = "OBCFEMALE" Then
            txtba1fees1.Text = txtba1fees.Text - "495"[Conversion from string "" to type 'Double' is not valid.]
        ElseIf txtcatgen.Text = "SCMALE" Then
            txtba1fees1.Text = "0"
        ElseIf txtcatgen.Text = "SCFEMALE" Then
            txtba1fees1.Text = "0"
        ElseIf txtcatgen.Text = "STMALE" Then
            txtba1fees1.Text = "0"
        ElseIf txtcatgen.Text = "STFEMALE" Then
            txtba1fees1.Text = "0"
        End If
    End Sub

in the textbox3 change the code are:

Private Sub txtba1fees1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtba1fees1.TextChanged
        If txtcatgen.Text = "GENERALMALE" Then
            txtba1fees2.Text = txtba1fees.Text - txtba1fees1.Text - "485"
        End If
        If txtcatgen.Text = "GENERALFEMALE" Then
            txtba1fees2.Text = txtba1fees.Text - "485"
        End If
        If txtcatgen.Text = "OBCMALE" Then
            txtba1fees2.Text = txtba1fees.Text - txtba1fees1.Text - "485"
        End If
        If txtcatgen.Text = "OBCFEMALE" Then
            txtba1fees2.Text = txtba1fees.Text - "485"
        End If
        If txtcatgen.Text = "SCMALE" Then
            txtba1fees2.Text = "0"
        End If
        If txtcatgen.Text = "SCFEMALE" Then
            txtba1fees2.Text = "0"
        End If
        If txtcatgen.Text = "STMALE" Then
            txtba1fees2.Text = "0"
        End If
        If txtcatgen.Text = "STFEMALE" Then
            txtba1fees2.Text = "0"
        End If
    End Sub

in this code the error showing in mention line

please help me it urgent

if is there any other way for achieve this task.

kindly help me.("_")

Answer 1

Hi Sunny,

Welcome to the MSDN forum.

I've tested your codes and got this exception if value of txtba1fees is nothing. For your issue, I suggest you validate its value before the calculate. 

You can add the following codes in txtba1fees_TextChanged method:

        Dim result As Double
        If Double.TryParse(txtba1fees.Text, result) = False Then
            txtba1fees.Text = 0
        End If

I hope this will be helpful.

Best regards,

---

Shanks Zen
MSDN Community Support | Feedback to us

Answer 2

hello Zen,

thanks for solving my problem.

u are great.

thanks again

if u have time please solve this problem because i am trying this from last one week.

how to generate unique ID based on combobox selection?

thanks again