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Using Settings

Using Settings, How to use settings to preserve information between runs.

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AdamSpeight2008
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19 Nov, 2008 - 03:29 PM

Post #1

Example: How many times has the user run this application.

Defining a Setting

Project -> Properties -> Settings

Now in the grid where is says Setting
Rename it to NumberOfTimesRun
This is the name of the setting. We'll be using this like it is variable later
Change the type to Long
This determines the type for this particular setting. More on this later.
Change the scope to User
Application - Specific to the application regardless of which user and are READ ONLY
User - Allow applies to the current user.

Set value to 0
This is the default value the setting will have.

CODE

Run it, see what happens.

Saving Them
Saving them isn't automatic

CODE

Resetting Them

CODE

Module Module1

    Sub Main()
        Console.WriteLine("Number of times run  {0} ", My.Settings.NumberOfTimesRun)
        My.Settings.NumberOfTimesRun += 1
        Console.WriteLine("Number of times run  {0} ", My.Settings.NumberOfTimesRun)
        ' Save the settings
        My.Settings.Save()
        Console.WriteLine("Reset to original (Y/N)")

        Select Case Console.ReadKey.KeyChar
            Case "Y", "y"
                'Reset them back to default values
                My.Settings.Reset()

        End Select

    End Sub

End Module

Advance Settings
Now you can save simple setting, I hear some of you say, "but what if I want store a list of things in the setting?"

Saving a List
Project -> Properties -> Settings
Add a setting call MyList
Type -> Browse -> System.Collections.ArrayList

CODE

Module Module1
       Sub Main()
        ' We need to check that the Settings.MyList is not Nothing, ie it is Empty
        If My.Settings.MyList Is Nothing Then
            ' If it is Nothing then create a new instance
            My.Settings.MyList = New ArrayList
        End If

        Console.WriteLine("MyLIst contains {0} items ", My.Settings.MyList.Count)
        My.Settings.MyList.Add("Dream In Code")
        Console.WriteLine("MyLIst contains {0} items ", My.Settings.MyList.Count)
        ' Save the settings
        My.Settings.Save()
        Console.WriteLine("Reset to original (Y/N)")
        Select Case Console.ReadKey.KeyChar
            Case "Y", "y"
                'Reset them back to default values
                My.Settings.Reset()
        End Select

    End Sub

End Module

Note: That we need to check that the Setting isn't Nothing

Now you're Settings using Code Ninja

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Rickster090

18 Dec, 2008 - 06:12 AM

Post #2

Nice 've been wondering about those settings...thanks for this cool Tut

AdamSpeight2008
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30 Dec, 2008 - 02:15 PM

Post #3

Additional Info

Be aware of this complication to using settings.

Premise of example: Checking to see if the application as been run more than once.

My.Settings.FirstRun = True.
You run the program.
A Conditional in the code tests to see if My.Settings.FirstRun equates to true.
It does and sets and saves My.Settings.FirstRun as False
You run the program again.
The conditional equate to false.

Anyone spot the problem?

Nope. The problem is that the setting persists between runs. So now if copy the exe it thinks it still been run more than once.
So a quick solution to is this

CODE

#Const DEBUG_KeepFirstRunAsTrue = True
#Const DEBUG_ResetSetting = True
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
#If DEBUG_KeepFirstRunAsTrue Then
  If My.Settings.FirstRun Then
   My.Settings.FirstRun = False
   My.Settings.Save()
   Beep()
  End If
#End If
#If DEBUG_ResetSetting Then
  My.Settings.Reset()
  My.Settings.Save()
#End If

By toggling the constants you can test the code and importantly reset the setting.

This post has been edited by AdamSpeight2008: 30 Dec, 2008 - 02:18 PM