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A Prize Console-ation in VB 2005

  • May 22, 2006
  • By Josh Fitzgerald
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The ConsoleProgressBar Class

I created the ConsoleProgressBar class to handle the details of initializing and updating the progress bar. The constructor takes one parameter, called MaximumValue:

Public Sub New(ByVal MaximumValue As Long)
   m_length          = Console.WindowWidth - 10
   m_left            = 7
   m_right           = m_left + m_length + 1
   m_progressBarRow  = 1
   m_messageBarRow   = m_progressBarRow + 1
   m_percentPosition = 4
   m_maximumValue    = MaximumValue
   m_currentValue    = 0
   Initialize()
End Sub

I hard-coded some of the values and computed others based on the hard-coded values. I made the class simple for this article, but you could extend the constructor to take other values as parameters to make the progress bar more configurable.

After initializing all of the member variables, I call the Initialize method, which in turn calls the InitializePercentComplete, InitializeProgressBar, and InitializeMessageBar methods. These methods don't do a whole lot; they just print a percent sign, a set of brackets to denote the ends of the progress bar, and the minimum and maximum values of the progress bar.

The Progress Bar Progresses

Nothing else happens with the ConsoleProgressBar object until the Update method is invoked:

Public Sub Update(ByVal CurrentValue As Long)
   m_currentValue = CurrentValue
   m_currentBarLength = CInt((m_currentValue / m_maximumValue) _
                              * m_length)
   Refresh()
End Sub

The Update method takes one value as a parameter, which in this case will be the current file number just copied. I set the member variable m_currentValue and then computed m_currentBarLength. The result of the computation gives the number of columns the progress bar should currently cover.

Finally, I call the Refresh method, which in turn calls the UpdatePercentComplete, UpdateProgressBar, and UpdateMessageBar methods.

Because all three methods are similar in function, I will focus on the UpdateProgressBar method:

Private Sub UpdateProgressBar()
   Dim originalForegroundColor As ConsoleColor = _
      Console.ForegroundColor
   Dim originalBackgroundColor As ConsoleColor = _
      Console .BackgroundColor
   Console.ForegroundColor = ConsoleColor.Black
   Console.BackgroundColor = ConsoleColor.Green
   Console.SetCursorPosition(m_left + 1 m_progressBarRow)
   Dim progress As New String("O", m_currentBarLength)
   Console.Write(progress)
   Console.ForegroundColor =originalForegroundColor
   Console.BackgroundColor = originalBackgroundColor
End Sub

Once again, the first thing the code does is save the current foreground and background colors. It then sets the ForegroundColor property to Black and the BackgroundColor property to Green. After positioning the cursor at the left edge of the progress bar, it prints a string of Os with a length of m_currentBarLength.

Running DirCopy

After so much description, you must be eager to see the application run (see Figures 2 and 3) and check out the results (see Figure 4). I've set up a directory with a bunch of dummy files to test copying. I recommend you do the same before you use DirCopy to copy any critical files.

Figure 2: Starting DirCopy

Figure 3: DirCopy Running

Figure 4: DirCopy Finished

What Else?

The DirCopy application, while potentially useful, is not quite production ready. To make it more robust, I would need to add lots more error handling (in other words, the boring, tedious stuff). You also could improve the ConsoleProgressBar class to allow more control. The following are some more possible enhancements:

  • Allow more control of the placement and length of the bar
  • Allow the percent complete area to be placed anywhere the programmer chooses
  • Allow custom messages in the message bar
  • Add an option to choose between a horizontal or vertical progress bar

More to Explore

I hope that this article has been useful in showing you some of the cool new console application features available in VB 2005. Although the features I covered are some of my favorites, I urge you to check the numerous other new console app features to find a few favorites of your own.

Download the Code

To download the accompanying source code for DirCopy, click here.

About the Author

Josh Fitzgerald is an applications development group leader for a large medical device company in Warsaw, Indiana. Designing and developing Visual Basic .NET applications is only one of his responsibilities, but it is his favorite part of his job. You can reach Josh at josh.fitzgerald@gmail.com.





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