Not sure how to use IsolatedStorage - vb.net

Question

I want to create a notes app for Windows Phone 7 using Visual Basic. I have read a few tutorials but they are all suited for C# not VB. Basically, I have a main page and a page to add notes. Once the user types out a note on the add notes page, the title of that note appears on the main page. I also want the user to be able to select that title and it will display the note. I have done a bit of research and I know I will need to use isolated storage (not sure how to implement it in VB) to save the notes. I think I will also need a list box that will store the title of the notes. I am not asking for someone to just give me code, I am asking for some tutorials regarding this in VB or any pointers or general help on acheiving this. Thanks

Answer 1

All the code samples on MSDN are available in both C# and VB. See http://msdn.microsoft.com/en-us/library/ff431744(v=vs.92).aspx
The Model-View-ViewModel Sample (under Common Application Development Tasks) is probably a good place for you to start.
The link to download the VB code is http://go.microsoft.com/fwlink/?LinkId=229339

Answer 2

You are correct that you will need to use IsolatedStorage if you're wanting to write the notes to the phone (and not the cloud somewhere). Here is a link to a blog entry that has a class (in Visual Basic) that has some helper methods that will give you some similiar methods to VB.Net traditional methods (like ReadAllText, WriteAllText). It may be what you want for the file system reading/writing (but at a minimum will get you started with Isolated Storage).
http://www.blakepell.com/2012-03-07-wp7-file-helpers

Answer 3

Isolated Storages
Isolated storage is used to store local files such as text files, images, videos etc on the Windows Phone. Each app is assigned a specific isolated storage and is exclusive ONLY to that app. No other app is able to access your apps isolated storage.
A lot can be read from here All about Windows Phone Isolated Storage
Before you begin you will need to import IsolatedStorage to your project.
Imports System.IO
Imports System.IO.IsolatedStorage
Creating Folders
This creates a directory in your apps isolated storage. It will be called "NewFolder"
Dim myIsolatedStorage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
myIsolatedStorage.CreateDirectory("NewFolder")
You can create folders inside folders inside folders like so:
myIsolatedStorage.CreateDirectory("NewFolder/NewFolder1/NewFolder2/NewFolder3")
To delete a folder:
myIsolatedStorage.DeleteDirectory("NewFolder")
A good practice when creating and deleting folders is to add a Try Catch statement around the folder creation method so if there is an exception you or the user will be notified as to why it occurs e.g. the folder not existing therefore cannot be deleted or the folder existing therefore needing to be replaced etc. The example below shows a basic function in creating a folder with a Try Catch statement.
Public Sub CreateDirectory(directoryName As String)
Try
Dim myIsolatedStorage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
If Not String.IsNullOrEmpty(directoryName) AndAlso Not myIsolatedStorage.DirectoryExists(directoryName) Then
myIsolatedStorage.CreateDirectory(directoryName)
End If
' handle the exception
Catch ex As Exception
End Try
End Sub
To use it you can do:
Me.CreateDirectory("NewFolder")
For the deletion method:
Public Sub DeleteDirectory(directoryName As String)
Try
Dim myIsolatedStorage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
If Not String.IsNullOrEmpty(directoryName) AndAlso myIsolatedStorage.DirectoryExists(directoryName) Then
myIsolatedStorage.DeleteDirectory(directoryName)
End If
' handle the exception
Catch ex As Exception
End Try
End Sub
And to use it:
Me.DeleteDirectory("NewFolder")
Creating Files
You can create an empty file like this:
Dim myIsolatedStorage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
Dim writeFile As New StreamWriter(New IsolatedStorageFileStream("NewFolder\SomeFile.txt", FileMode.CreateNew, myIsolatedStorage))
To delete the file:
myIsolatedStorage.DeleteFile("NewFolder/SomeFile.txt")
Like before, a good practise when it comes to creating files is to always check if the directory you are writing to or deleting exists.
You can do something like:
Try
Dim myIsolatedStorage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
Dim writeFile As StreamWriter
If Not myIsolatedStorage.DirectoryExists("NewFolder") Then
myIsolatedStorage.CreateDirectory("NewFolder")
writeFile = New StreamWriter(New IsolatedStorageFileStream("NewFolder\SomeFile.txt", FileMode.CreateNew, myIsolatedStorage))
Else
writeFile = New StreamWriter(New IsolatedStorageFileStream("NewFolder\SomeFile.txt", FileMode.CreateNew, myIsolatedStorage))
End If
' do something with exception
Catch ex As Exception
End Try
Saving and Reading Text Files
To save a text file with your content you can do something like:
Dim myIsolatedStorage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
Using writeFile As New StreamWriter(New IsolatedStorageFileStream("myNote.txt", FileMode.Create, FileAccess.Write, myIsolatedStorage))
Dim someTextData As String = "This is some text data to be saved in a new text file in the IsolatedStorage!"
writeFile.WriteLine("note data")
writeFile.Close()
End Using
To read the contents of the Text File:
Dim myIsolatedStorage As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication()
Dim fileStream As IsolatedStorageFileStream = myIsolatedStorage.OpenFile("myFile.txt", FileMode.Open, FileAccess.Read)
Using reader As New StreamReader(fileStream)
TextBlock.Text = reader.ReadLine()
End Using
I've provided you with some of the basics of the Windows Phone Isolated Storage and how to use it but I highly suggest that you read more about it at Here