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The Color Changer Application
 

Introduction

In this application, we will use three scroll bars to change the background color of a panel.

  1. Start Microsoft Visual Basic and create a Standard EXE application
  2. Save the application in a new folder named Color Changer
  3. Save the form as frmMain and save the project as ColorChanger
  4. Design it as follows
     
    Control Properties
    Form Name: frmMain
    Border Style: 3 - FixedDialog
    Caption: Color Changer
    PictureBox Name: pctPreview
    VScrollBar Name: scrRed
    Max: 255
    VScrollBar Name: scrGreen
    Max: 255
    VScrollBar Name: scrBlue
    Max: 255
    CommandButton Name: cmdClose
    Caption: Close
    Label Name: lblRed
    Alignment: 2 - Center
    Caption: 000
    Label Name: lblGreen
    Alignment: 2 - Center
    Caption: 000
    Label Name: lblBlue
    Alignment: 2 - Center
    Caption: 000
  5. Double-click an unoccupied area on the form and implement its OnLoad event as follows:
      
    Private Sub Form_Load()
    pctPreview.BackColor = RGB(128, 128, 128)
    scrRed.Value = 127
    scrGreen.Value = 127
    scrBlue.Value = 127
End Sub
  6. Double-click the Close button and implement its OnClick event as follows:
      
    Private Sub cmdClose_Click()
    End
End Sub
  7. Double-click the left ScrollBar control on the form to access its OnChange event
  8. In the same way, double-click the middle and the right scroll bars
  9. In the code editor, when the caret is positioned in the OnChange event of a scroll bar, in the Procedure combo box, select the Change event
  10. Implement the events as follows:
      
    Option Explicit

Private Sub cmdClose_Click()
    End
End Sub

Private Sub Form_Load()
    pctPreview.BackColor = RGB(128, 128, 128)
    scrRed.Value = 127
    scrGreen.Value = 127
    scrBlue.Value = 127
End Sub

Private Sub scrBlue_Change()
    Dim ValueRed As Integer
    Dim ValueGreen As Integer
    Dim ValueBlue As Integer
    
    ValueRed = 255 - scrRed.Value
    ValueGreen = 255 - scrGreen.Value
    ValueBlue = 255 - scrBlue.Value
    
    pctPreview.BackColor = RGB(ValueRed, ValueGreen, ValueBlue)
    lblRed.Caption = CStr(ValueRed)
    lblGreen.Caption = CStr(ValueGreen)
    lblBlue.Caption = CStr(ValueBlue)
End Sub

Private Sub scrBlue_Scroll()
    scrBlue_Change
End Sub

Private Sub scrGreen_Change()
    Dim ValueRed As Integer
    Dim ValueGreen As Integer
    Dim ValueBlue As Integer
    
    ValueRed = 255 - scrRed.Value
    ValueGreen = 255 - scrGreen.Value
    ValueBlue = 255 - scrBlue.Value
    
    pctPreview.BackColor = RGB(ValueRed, ValueGreen, ValueBlue)
    lblRed.Caption = CStr(ValueRed)
    lblGreen.Caption = CStr(ValueGreen)
    lblBlue.Caption = CStr(ValueBlue)
End Sub

Private Sub scrGreen_Scroll()
    scrGreen_Change
End Sub

Private Sub scrRed_Change()
    Dim ValueRed As Integer
    Dim ValueGreen As Integer
    Dim ValueBlue As Integer
    
    ValueRed = 255 - scrRed.Value
    ValueGreen = 255 - scrGreen.Value
    ValueBlue = 255 - scrBlue.Value
    
    pctPreview.BackColor = RGB(ValueRed, ValueGreen, ValueBlue)
    lblRed.Caption = CStr(ValueRed)
    lblGreen.Caption = CStr(ValueGreen)
    lblBlue.Caption = CStr(ValueBlue)
End Sub

Private Sub scrRed_Scroll()
    scrRed_Change
End Sub
  11. Test the application
 
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