Temperature Conversion with Multiple Base in VB6

In the earlier posting you have learnt several simple VB programming tips how to convert temperature with basis Celcius, Fahrenheit, Rheamur and Kelvin. In this posting you will learn how to make a simple application to convert temperature with multiple basis with VB6 programming. You can select the temperature basis when the program's running.

The scenario of this simple application is as follow:

You can select the temperature basis when the program's running

Once you select a temperature basis the conversion process will occur when a value of temperature is not empty (contains a number)

Also when you typing a temperature on the temperature text box conversion process will automatically occurs

When you typing a number in temperature box, if the basis is empty, it will be automatically set to "Celcius" as default

Now, how to built your simple application? Let's go on to the simple VB programming tips.
First, you have to create a screen design likes below image:



How to create the screen design? Follow step by step of below instructions:

Open your VB program, create a project (Project1) and a standard form (Form1)

Create 7 label controls

Change the label captions into Temperature Conversion, Temperature, Celcius, Fahrenheit, Rheamur, Kelvin, and Basis

Create 5 text box controls

Clear the text of each text box

Rename the text box 1,2,3,4 and 5 into TxtTem, TxtCel, TxtFah, TxtRhe, and TxtKel

Create a combo box

Clear the combo box text

Rename the combo box into cboBasis
Ok, the screen design already finished. Now, what's the program coding like?

Here it is the program coding. Follow the next simple VB programming tips.

Double-click anywhere in form1 area to create Sub Procedure Form_Load()

Write down below program coding in Sub Procedure Form_Load() area

    'to add items in combo box
    cboBasis.AddItem "Celcius"
    cboBasis.AddItem "Fahrenheit"
    cboBasis.AddItem "Rheamur"
    cboBasis.AddItem "Kelvin"

Double-click TxtTemp text box to create a Sub TxtTemp_Change()

Write down below program coding in the Sub TxtTemp_Change() area

    'call procedure ConvPro
    ConvPro

Double-click cboBasis object

In the program editor window select "Click" event from drop-down list to create Sub cboBasis_Click()

Write down below program code in the Sub cboBasis_Click() area

    'call procedure ConvPro
    ConvPro

In the program editor window click General from drop-down list

Write down below program code in (General) - (Declarations) area to create a Sub ConvPro()

   Private Sub ConvPro()
     If TxtTemp.Text = "" Then
        'clear the text of text boxes
        TxtCel.Text = ""
        TxtFah.Text = ""
        TxtRhe.Text = ""
        TxtKel.Text = ""
        Exit Sub
     End If

     'if Basis is blank then fill in with "Celcius" as default
     If cboBasis.Text = "" Then
        cboBasis.Text = "Celcius"
     End If
     Select Case cboBasis.Text
       Case "Celcius"
          GoTo ConvCel
       Case "Fahrenheit"
          GoTo ConvFah
       Case "Rheamur"
          GoTo ConvRhe
       Case Else
          GoTo ConvKel
     End Select

   'conversion for celcius basis
   ConvCel:
      TxtCel.Text = Val(TxtTemp.Text)
      TxtFah.Text = Val(TxtTemp.Text) * 1.8 + 32
      TxtRhe.Text = Val(TxtTemp.Text) * 0.8
      TxtKel.Text = Val(TxtTemp.Text) + 273.15
      Exit Sub

   'conversion for fahrenheit basis
   ConvFah:
      TxtFah.Text = Val(TxtTemp.Text)
      TxtCel.Text = (Val(TxtTemp.Text) - 32) / 1.8
      TxtRhe.Text = ((Val(TxtTemp.Text) - 32) / 1.8) * 0.8
      TxtKel.Text = ((Val(TxtTemp.Text) - 32) / 1.8) + 273.15
      Exit Sub

   'conversion for rheamur basis
   ConvRhe:
      TxtRhe.Text = Val(TxtTemp.Text)
      TxtCel.Text = Val(TxtTemp.Text) / 0.8
      TxtFah.Text = ((Val(TxtTemp.Text) / 0.8) * 1.8) + 32
      TxtKel.Text = (Val(TxtTemp.Text) / 0.8) + 273.15
      Exit Sub

   'conversion for kelvin basis
   ConvKel:
      TxtKel.Text = Val(TxtTemp.Text)
      TxtCel.Text = Val(TxtTemp.Text) - 273.15
      TxtRhe.Text = (Val(TxtTemp.Text) - 273.15) * 0.8
      TxtFah.Text = ((Val(TxtTemp.Text) - 273.15) * 1.8) + 32
   End Sub

So your program will look like below listing:

   Private Sub ConvPro()
      If TxtTemp.Text = "" Then
         'clear text of text boxex
         TxtCel.Text = ""
         TxtFah.Text = ""
         TxtRhe.Text = ""
         TxtKel.Text = ""
         Exit Sub
      End If
      'if Basis is blank then fill in with "Celcius"
      If cboBasis.Text = "" Then
         cboBasis.Text = "Celcius"
      End If
      Select Case cboBasis.Text
         Case "Celcius"
            GoTo ConvCel
         Case "Fahrenheit"
            GoTo ConvFah
         Case "Rheamur"
            GoTo ConvRhe
         Case Else
            GoTo ConvKel
      End Select

   'conversion for celcius basis
   ConvCel:
         TxtCel.Text = Val(TxtTemp.Text)
         TxtFah.Text = Val(TxtTemp.Text) * 1.8 + 32
         TxtRhe.Text = Val(TxtTemp.Text) * 0.8
         TxtKel.Text = Val(TxtTemp.Text) + 273.15
         Exit Sub

   'conversion for fahrenheit basis
   ConvFah:
         TxtFah.Text = Val(TxtTemp.Text)
         TxtCel.Text = (Val(TxtTemp.Text) - 32) / 1.8
         TxtRhe.Text = ((Val(TxtTemp.Text) - 32) / 1.8) * 0.8
         TxtKel.Text = ((Val(TxtTemp.Text) - 32) / 1.8) + 273.15
         Exit Sub

   'conversion for rheamur basis
   ConvRhe:
         TxtRhe.Text = Val(TxtTemp.Text)
         TxtCel.Text = Val(TxtTemp.Text) / 0.8
         TxtFah.Text = ((Val(TxtTemp.Text) / 0.8) * 1.8) + 32
         TxtKel.Text = (Val(TxtTemp.Text) / 0.8) + 273.15
         Exit Sub

   'conversion for kelvin basis
   ConvKel:
         TxtKel.Text = Val(TxtTemp.Text)
         TxtCel.Text = Val(TxtTemp.Text) - 273.15
         TxtRhe.Text = (Val(TxtTemp.Text) - 273.15) * 0.8
         TxtFah.Text = ((Val(TxtTemp.Text) - 273.15) * 1.8) + 32

   End Sub



   Private Sub cboBasis_Click()
      'call procedure ConvPro
      ConvPro
   End Sub


   Private Sub Form_Load()
      'to add items in combo box
      cboBasis.AddItem "Celcius"
      cboBasis.AddItem "Fahrenheit"
      cboBasis.AddItem "Rheamur"
      cboBasis.AddItem "Kelvin"
   End Sub


   Private Sub TxtTemp_Change()
      'call procedure ConvPro
      ConvPro
   End Sub

Run your program by clicking Start button on your VB Toolbar

Type a number in the text box with label Temperature

Select and click different Base from the list on the combo box
What happen? The conversion should automatically occurs, so the results appear on the each text box. Look at below image for your illustration. Your program should look like it.

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