Arithmetic Operations in a Userform - vba

Question

I have made the userform so I will use that to describe my problem.
I want to take four user inputs (cost of product, number of units sold, number of units returned, and cost of fix per unit) and calculate 6 things from it such as total earnings (cost of product x number of units sold) and total returned cost (cost of product x number of units returned).
How would I go about writing the code?
Userform image here: http://imgur.com/a/qc3Kk

Answer 1

So, here is my take on this solution. It isn't a very complicated program to create. Overall, it is one UserForm, following the design of yours in the image with one section of code doing the calculations and one section of code that ensures the values input in the textboxes are numeric. The interface is a combination of labels and textboxes:
There is a code for each textbox that evaluates whether the value entered is numerica and alerts you if it is not. Each routine uses the IsNumeric function for the purpose and also sees if there is a value in the textbox at all. The AfterUpdate event ensures that the routine only runs after you input something. You have the option of either having a routine for each textbox separately, or write a more integrated routine in a module that each textbox references. For the sake of the example:
Private Sub txtCost_AfterUpdate()
With UserForm1
With .txtCost
If Not IsNumeric(.Value) Or .Value = "" Then
MsgBox "Please enter a numeric value only!"
End If
End With
End With
End Sub
Private Sub txtReturned_AfterUpdate()
With UserForm1
With .txtReturned
If Not IsNumeric(.Value) Or .Value = "" Then
MsgBox "Please ensure you enter only numeric values"
End If
End With
End With
End Sub
Private Sub txtTotalFix_AfterUpdate()
With UserForm1
With .txtTotalFix
If Not IsNumeric(.Value) Or .Value = "" Then
MsgBox "Please ensure you enter only numeric values"
End If
End With
End With
End Sub
Private Sub txtUnits_AfterUpdate()
With UserForm1
With .txtUnits
If Not IsNumeric(.Value) Or .Value = "" Then
MsgBox "Please ensure you enter only numeric values"
End If
End With
End With
End Sub
The meat and potatoes of the routine are also not complicated. I've directly used the values of each textbox to spit out the values of the computations. Alternatively, you might choose to use variables (I've decalred x As Double, because you could be dealing with quite large numbers, but it isn't used in this example). The routine lives in Module1 and checks that all the values are numbers with the same IsNumeric function and runs through the formulas, alerting you if any of them are empty or not a number. I wasn't positive of how you calculated savings or your criteria of YES or NO, so you may have to adjust that.
Sub QA_prog()
Dim x As Double
With UserForm1
If IsNumeric(.txtCost.Value) And IsNumeric(.txtUnits.Value) _
And IsNumeric(.txtReturned.Value) And IsNumeric(.txtTotalFix.Value) Then
.lblEarn.Caption = .txtCost.Value * .txtUnits.Value
.lblTRC.Caption = .txtCost * .txtTotalFix
.lblProfit = .lblEarn.Caption - .lblTRC.Caption
.lblCostFix = .txtReturned * .txtTotalFix
.lblTE.Caption = .lblProfit - .lblCostFix
.lblSave.Caption = .lblTRC + .lblCostFix
If .lblSave.Caption > 5000 Then
.txtYorN.Text = "NO"
Else
.txtYorN.Text = "YES"
End If
Else
MsgBox "Double check your values!"
End If
End With
End Sub
Finally, the buttons. Exit button closes the program using Unload:
Private Sub cmdExit_Click()
Unload UserForm1
End Sub
Calculate button calls the QA Sub routine:
Private Sub cmdCalc_Click()
Module1.QA_prog
End Sub
To trigger the program, you just need to add a button to the spreadsheet and type "UserForm1.show" in its code window to activate the program.