Customizing My.Namespace

[kevininstructor]

The following focuses on one idea for reducing the amount of code you type, centralizing code used often in development of solutions and to expose functionality within the .NET Framework that is rarely used but when needed, is needed now.

One of the most common thing we do with users is to communicate with them using dialogs such as MsgBox which works great for most of the time yet can fall short say if you need ask a question and want the NO button as the default button which means you need the MessageBox class. The problem with the MessageBox is that by the time you are finished constructing a dialog it is a long line of code and you need to repeat it over and over again or place the code in a module and go from there.

One possible method to assist in the above is to extend My Namespace.

MSDN http://msdn.microsoft.com/en-us/library/bb531245.aspx
The My namespace in Visual Basic exposes properties and methods that enable you to easily take advantage of the power of the .NET Framework. The My namespace simplifies common programming problems, often reducing a difficult task to a single line of code. Additionally, the My namespace is fully extensible so that you can customize the behavior of My and add new services to its hierarchy to adapt to specific application needs. This topic discusses both how to customize existing members of the My namespace and how to add your own custom classes to the My namespace.

So instead of the following

If Windows.Forms.MessageBox.Show("Your question", "Question", _
                                 Windows.Forms.MessageBoxButtons.YesNo, _
                                 Windows.Forms.MessageBoxIcon.Question, _
                                 MessageBoxDefaultButton.Button2) = _
                                 Windows.Forms.DialogResult.Yes Then
End If

By extending My Namespace we could have this.

If My.Dialogs.Question("Your question", "question") Then

End If

Another tedious message to display is when an exception has to be displayed to users (personally I have a class which handles unhandled exceptions coupled with a replacement for globally handling unhandled exceptions). Take the following example which shows a personal message coupled with the text from the exception.

Try
   DirectCast(sender, ListBox).Items.Add("Ha Ha")
Catch ex As Exception
   MsgBox(String.Format("I goofed up{0}{1}", _
                        Environment.NewLine, ex.Message))
End Try

Again using an extension to My namespace we could wrap this up and also format the dialog as shown below.

Try
   DirectCast(sender, ListBox).Items.Add("Ha Ha")
Catch ex As Exception
   My.Dialogs.ExceptionDialog("I goofed up", "Oooops", ex)
End Try

Another extension included checks against a list to see if the current user is either a tester or developer. When I develop solutions I will place information on the UI but will hide the information from testers and users. A clear and simple example, the design of the solution dictates that the user is prompted Yes/No to leave the application yet I do not want to be asked so the following is used which is an extension of Windows.Forms which uses an extension to My Namespace.

<Runtime.CompilerServices.Extension()> _
Sub CloseThisForm(ByRef sender As Windows.Forms.Form)
   If My.CurrentUser.IsTester Then
      If My.Dialogs.Question("Close?") Then
         sender.Close()
      End If
   Else
      sender.Close()
   End If
End Sub

In the close button of the main form (handling the form’s control box not handled here)

Me.CloseThisForm()

Another example, you need to display the system up time.

My.Dialogs.InformationDialog(My.Computer _
                             .SystemUpTime.ToString, "System up time")
Console.WriteLine(My.Computer.SystemUpTime.ToString)
Ouputs 08:52:41.7990000

Or broken down by hour and minutes

Dim UpTime = My.Computer.SystemUpTime
Console.WriteLine("{0}:{1}", UpTime.Hours, UpTime.Minutes)
Outputs 8:54

For me an extension of My Namespace deals with my database, IBM-DB2 where I target a solution for a specific version of IBM Client Access to be pro-active and stop database access before an exception is raised. The following is not included in the attached project.

If My.iSeries.CorrectVersionInstalled Then
    Console.WriteLine("Perform data operations against DB2")
Else
    Console.WriteLine(My.iSeries.ExceptionMessage)
End If

To see if Client Access is installed

My.iSeries.AssemblyExists

What version is installed

My.iSeries.InstalledVersion

Any ways the attached project should help you with My.Dialogs for simplifying showing messages to users and also assist with creating your own partial classes and new classes under My.Namespace.

• Attached project is VS2008, code should work fine in VS2005 although I have not tested under VS2005 so it might need some tweaking.
• There are more dialogs than discussed here in the attached zip file

[kevininstructor]

Perhaps you have some functionality which seems right for My.Computer such as returning a list of installed versions of the Microsoft Framework or simple return the current user’s My Document folder. Both of these are actually easy to write code when needed but at least for me are longer than I want to type. Any ways the attached demonstration project shows demos the following.

My.Computer.Printers
Returns a list of all known printers on the current computer

My.Computer.DefaultPrinterName
Returns the default printer for the current user

My.Computer.WindowsFolder
Install folder for MS-Windows

My.Computer.MyDocumentsFolder
Current user's My Document folder

My.Computer.RuntimeVersions
List of installed Frameworks

My.Computer.InternetExplorerInstalled
Is Microsoft Internet Explorer installed on the current computer

My.Computer.InternetExplorerExecutable
Path and executable to fire up IE perhaps with a file

There are a few other properties added and all the above are demo'd.

Any ways let's say this is food for thought.

[vb_ftw]

this is really nice...framework versions is great
nice job...keep it up

[kevininstructor]

There are times when a developer wants to change the button labels of a MsgBox or MessageBox regardless of whether this is not the best method to go since the better method is to create a form and adorn it with buttons which set the dialog result. The attached project has three functions callable under a custom My Namespace My.Dialogs. The code to change the button text is from another developer, his name and location of the original code is within the code.

Display an exceptions style dialog with Ooooops as the single button text

      Try
         DirectCast(sender, ListBox).SelectedIndex = 0
      Catch ex As Exception
         Dim Message As String = String.Format("Encountered the following{0}{1}", _
                                               Environment.NewLine, ex.Message)
         My.Dialogs.ExceptionDialog(Message, "Error", "Ooooops")
      End Try

Setting button text on the fly for asking a question which returns a Boolean. The text for the buttons is obtained from two TextBoxs. In the function Question there is a check to see if the button text length is greater than 10 and if so truncated which can easily be taken out.

      If My.Dialogs.Question("Your Question", "My Title", txtYes.Text, txtNo.Text) Then
         ActiveControl = txtYes
      Else
         ActiveControl = txtNo
      End If

Ask the user if they want to close a form, with a tad bit of humor.

   Private Sub frmMainForm_FormClosing( _
      ByVal sender As Object, _
      ByVal e As System.Windows _
         .Forms.FormClosingEventArgs) Handles Me.FormClosing

      e.Cancel = Not _
      My.Dialogs.RedNeckQuestion("Do ja wantta leave dis program", "Da Question")

   End Sub

[kevininstructor]

The following provides a new addition for current culture. Feel free to add or remove functions to this class.

I focused more on date/time but added other elements in too.

See attached VS2010 project for full source and demo

Current function list

AbbreviatedDayNames
Returns a string array of day names abbreviated

AbbreviatedMonthNames
Returns a string array of month names abbreviated

CurrentDayName
Returns the name of the current day

CurrencySymbol
Returns the char for the currency symbol

CultureList
Returns a list suitable for finding specific cultures

DateSeparator
Returns the char used to work with date parts

DayNames
Returns a string array of fulll day names

TimeSepartor
Returns the char used to work with time

MonthNames
Returns a string array of full month names

Source

Namespace My
    <Global.System.ComponentModel.EditorBrowsable(Global.System.ComponentModel.EditorBrowsableState.Never)> _
    Partial Friend Class _Culture
        Public Function DateSeparator() As String
            Return System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.DateSeparator
        End Function
        ''' <summary>
        ''' Return the Time Separator for current culture
        ''' </summary>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public Function TimeSepartor() As String
            Return System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.TimeSeparator
        End Function
        ''' <summary>
        ''' Return CurrencySymbol for current culture
        ''' </summary>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public Function CurrencySymbol() As String
            Return System.Globalization.CultureInfo.CurrentCulture.NumberFormat.CurrencySymbol
        End Function
        ''' <summary>
        ''' Return a string array of Abbreviated Day Names for current culture
        ''' </summary>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public Function AbbreviatedDayNames() As String()
            Return System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.AbbreviatedDayNames
        End Function
        Public Function AbbreviatedMonthNames() As String()
            Return System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.AbbreviatedMonthNames
        End Function
        ''' <summary>
        ''' Returns a string array of day names for the current culture
        ''' </summary>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public Function DayNames() As String()
            Return System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.DayNames
        End Function
        ''' <summary>
        ''' Returns a string array of month names for the current culture
        ''' </summary>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public Function MonthNames() As String()
            Return (From M In System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.MonthNames Where Not String.IsNullOrEmpty(M)).ToArray
        End Function
        ''' <summary>
        ''' Returns the current month long name for the current culture
        ''' </summary>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public Function CurrentMonthName() As String
            Return System.Text.RegularExpressions.Regex.Replace(Now.ToString("y"), "[^A-Za-z\.]", "")
        End Function
        Public Function CultureList() As Globalization.CultureInfo()
            Return (From T In Globalization.CultureInfo.GetCultures(Globalization.CultureTypes.SpecificCultures) Order By T.EnglishName).ToArray
        End Function
        ''' <summary>
        ''' Returns the current long day name for the current culture
        ''' </summary>
        ''' <returns></returns>
        ''' <remarks></remarks>
        Public Function CurrentDayName() As String
            Return Now.DayOfWeek.ToString
        End Function
    End Class
    <Global.Microsoft.VisualBasic.HideModuleName()> _
    Friend Module KSG_Culture
        Private instance As New ThreadSafeObjectProvider(Of _Culture)
        ReadOnly Property Culture() As _Culture
            Get
                Return instance.GetInstance()
            End Get
        End Property
    End Module
End Namespace