Loading from a .dat file into a listbox

[Lanc1988]

I am working on building a web browser for my program and I have been trying to add a way for the user to add their own favorites. So I have a place where they click Add to Favorites and they are asked for the url of the site they want to add, then it is added to a .dat file, here is the code used for saving the favorites:

 

      'Saves favorites url to file
       Dim sw As System.IO.StreamWriter = _
   New System.IO.StreamWriter(Application.StartupPath & "\Sidekick Files\Settings\Favorites.dat", True)
       Try
           sw.WriteLine(MyFavoritesURL & vbTab & MyFavoritesURL)
           sw.Flush()
       Catch ex As Exception
           MsgBox(ex.ToString, MsgBoxStyle.Exclamation, "Error saving new favorites URL. Please contact developer.")
       Finally
           sw.Close()
           sw = Nothing
       End Try

       MessageBox.Show("My Favorites URL Successfully Saved!")

 

and here is the code that I have to load the favorites into a listbox:

 

       'Loads Favorites into listbox
       Dim MyFavoritesURL As String
       Dim sr As System.IO.StreamReader = _
   New System.IO.StreamReader(Application.StartupPath & "\Sidekick Files\Settings\Favorites.dat")
       Dim line, vals() As String
       Do
           line = sr.ReadLine
           If line Is Nothing Then Exit Do
           vals = line.Split(vbTab)
           If vals(0) = MyFavoritesURL Then
               lbFavorites.Items.Add(vals(1))
           End If
       Loop

       sr.Close()
       sr = Nothing

 

Now the problem is that its not loading anything into the listbox.. anyone see a problem with any of that code?

 

Thanks

[Mothra]

In your code...

       'Loads Favorites into listbox
       Dim MyFavoritesURL As String
       Dim sr As System.IO.StreamReader = _
   New System.IO.StreamReader(Application.StartupPath & "\Sidekick Files\Settings\Favorites.dat")
       Dim line, vals() As String
       Do
           line = sr.ReadLine
           If line Is Nothing Then Exit Do
           vals = line.Split(vbTab)
           If vals(0) = MyFavoritesURL Then
               lbFavorites.Items.Add(vals(1))
           End If
       Loop

       sr.Close()
       sr = Nothing

 

...where are you setting the value of MyFavoritesURL? I ran the following code (giving MyFavoritesURL a value) and it worked fine.

 

Dim MyFavoritesURL As String = "Test 1"
	Dim sr As System.IO.StreamReader = _
   New System.IO.StreamReader(Application.StartupPath & "\Favorites.dat")
	Dim line, vals() As String
	Do
		line = sr.ReadLine
		If line Is Nothing Then Exit Do
		vals = line.Split(CType(vbTab, Char))
		If vals(0) = MyFavoritesURL Then
			ListBox1.Items.Add(vals(1))
		End If
	Loop

	sr.Close()
	sr = Nothing

You may just need to make sure that the varible is being set correctly.

[Lanc1988]

yes, it works fine now, thanks

 

I also would like to know if anyone knows how I can remove certain lines from the .dat file, in other words remove favorites?

[Denaes]

yes, it works fine now, thanks

 

I also would like to know if anyone knows how I can remove certain lines from the .dat file, in other words remove favorites?

 

your ".dat" is just a fancy word for plain text file it looks like.

 

If you want real capabilities for manipulating data without recreating the wheel, look into XML files. You'd just load your Favorites up like a database and delete a row if you didn't want it.

 

But to effectively delete a row from a plain text file, you need to write over the existing data - without that line of data.

 

If you read into a String Array, you have to write the file again, but without that index you don't want.

 

Easier to do with a Collection or HashTable.

 

Dim FavoritesHash as new HashTable

FavoritesHash.add(key, object)

 

so to add:

 

FavoritesHash.add(FavoriteName, FavoriteAddress)

 

to delete:

 

FavoritesHash.delete(FavoriteName)

 

then to write you do this:

 

dim favorite as string
ForEach favorite in FavoritesHash
'code to write line... something like:
Write(favorite.key & " " & favorite.Value) 
'Remember that .key is the name and .value is the object holding the html address
End For

 

many more ways to skin a cat :D

[Lanc1988]

k, thanks everything working perfectly