How do I code a LinkedList in VB.Net?

[The Thing]

Hello everybody,

I am new to all things .Net, but have several years experience of OOP in Java from my college days.

I have recently written a sliding block/tile type puzzle game in Java and I would now like to rewrite it in VB.Net. The programming construct I used to manage the logic behind the game was a LinkedList - each element of the list represented one block/tile.

Basically speaking In Java I coded the following:

LinkedList tileManager = new LinkedList();

Then after populating my list like so:

//The int[] tileLayout was used to hold the colour values
//of the tiles - 0 for black, 1 for white.
public void populateLinkedList(int[] tileLayout)
{
	
	for(int i = 0; i < tileLayout.length; i++)
	{
			
		tileManager.add((Integer)tileLayout[i]);
			
	}	
				
}

I could move the tiles in the list in the following manner.

//Note that the boolean variable direction used below was initialised 
//earlier in the code depending on the users actions.
if(direction==true)
{
	//Move the tiles clockwise in the list.	
	tileManager.addFirst(tileManager.removeLast());
			
}
else if(direction==false)
{
	
	//Move the tiles anti-clockwise in the list.	
	tileManager.addLast(tileManager.removeFirst());
			
}

How then would I go about coding the same functionality in VB.Net?

Thank you for your help.

Regards,

The Thing.

[jmcilhinney]

.NET 2.0 has a LinkedList class. That code would be almost exactly the same in C# as it is in Java. There are links to C# -> VB.NET converters in my signature. Have a ball.

[SeanGrebey]

I mean, you could right your own really easily. On the fly untested something like:

Public Class clsTile
    Public value As Int16
    Public NextT As clsTile
    Public PrevT As clsTile
End Class
 
Public Class MyLinkedList
    Private First As clsTile
    Private Last As clsTile
 
    Public Sub AddFirst(ByVal oTile As clsTile)
 
        If First Is Nothing Then
            oTile = First
            oTile = Last
            oTile.NextT = Nothing
            oTile.PrevT = Nothing
        Else
            First.PrevT = oTile
            oTile.NextT = First
            oTile.PrevT = Nothing
            First = oTile
        End If
    End Sub
 
    Public Sub AddLast(ByVal oTile As clsTile)
        If Last Is Nothing Then
            oTile = First
            oTile = Last
            oTile.NextT = Nothing
            oTile.PrevT = Nothing
        Else
            Last.NextT = oTile
            oTile.PrevT = Last
            oTile.NextT = Nothing
            Last = oTile
        End If
    End Sub
 
    Public Function RemoveFirst(ByVal oTile As clsTile) As clsTile
        Dim oReturn As clsTile
 
        oReturn = First
 
        If oReturn.NextT Is Nothing = False Then
            First = oReturn.NextT
            oReturn.PrevT = Nothing
        Else
            First = Nothing
            Last = Nothing
        End If
 
        oReturn.NextT = Nothing
        oReturn.PrevT = Nothing
 
        Return oReturn
    End Function
 
    Public Function RemoveLast(ByVal oTile As clsTile) As clsTile
        Dim oReturn As clsTile
 
        oReturn = Last
 
        If oReturn.PrevT Is Nothing = False Then
            Last = oReturn.PrevT
            oReturn.NextT = Nothing
        Else
            First = Nothing
            Last = Nothing
        End If
 
        oReturn.NextT = Nothing
        oReturn.PrevT = Nothing
 
        Return oReturn
    End Function
End Class

[The Thing]

Hi folks, thanks for your help.

Really the only reason I used a linked list was for convenience - the ease in which I could shift the tiles left or right in the list using a single line of code:

tileManager.addFirst(tileManager.removeLast());

I had two classes - one to handle the display, and another to handle the logic behind the game. The class handling the display used an int[] to store the colour values (0 or 1) of the tiles so perhaps a simple sub-routine/function which takes, manipulates, and returns an int[] is the way to go.

Thanks again.

The Thing.

[Shaggy Hiker]

I would stick with the class concept, though you might alter the functionality somewhat. Returning an array would be possible, but it seems like an ugly solution. Better to have the array wrapped in a class, with the function as a memeber that manipulates it.