I got one Array Copying Question For Y'all

J

JCreationsInc

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May 2, 2003
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Welll hello again it is I mogore the great with an array problem for you people to digest. I have searched far and wide in the ever confusing world of the VS.Net Combined Help to no avail. And it is now that I bow down to behold the true power of the dotnetforums! Anyways heres what is happening.

I have and array of type Object, and I need to make an exhact copy of it to work on without disturbing the original array (and this is where I run into a brick wall at full speed) I am using the Array.Copy function and it seems to work except when I alter the array, the origianl copy that I do not want altered gets altered. Here is my code:

Visual Basic: 
'The items array mentioned is a multi-dimensional object array 
'with each element initialized to a different class that holds 
'properties of items such as controls and images

'Copy our items array into our working array
Dim ItemsClone(Items.GetUpperBound(0)) As Object
Items.Copy(Items, ItemsClone, Items.GetUpperBound(0))

According to the help, a reference type array is being copied instead of a value type array(which is what I want) so when I alter the "ItemsClone" array it alters the original "Items" array(which is what I dont want)

Here is a portions from the help file:
"If sourceArray and destinationArray are both reference-type arrays or are both arrays of type Object, a shallow copy is performed. A shallow copy of an Array is a new Array containing references to the same elements as the original Array. The elements themselves or anything referenced by the elements are not copied. In contrast, a deep copy of an Array copies the elements and everything directly or indirectly "

So... Does anyone know how to create a "Deep" copy? or do I need to use a another Type for my array instead of Object?
 
How this thing works

I will explain the program in detail so everybody will have a better understanding of how the array that is giving me problems is set up, incase I am doing somthing wrong. Well anyways I am creating a program that will allow me or anyone who uses my applications to easily create "Skins" for my applications. It functions like a WYSIWYG editor and allows you to position and set the properties of the controls on the window to match the theme of your Skin.

So it works like this, there is a file I call it the "Master Skin File" the application reads a directory where the Master Skin Files are installed and loads the available files into a ComboBox. Then the user selects a Program(depending on the available master skin files) to create a project. Then the application proceeds to read the selected Master Skin File to determine how many dimensions will be needed for the Items Array that will eventually hold all the properties for the controls in the project.

The Items List is initialized to 2 dimensions. The first dimension contains the number of windows as stated in the master skin file. Then another function determines the type of the each control and initializes the array element within the current window dimension to the a Custom Class that will hold all the properties (such as position and color) for that control.

Visual Basic: 
'I have a couple of classes the hold properties of various items such as 
'ComboBoxes, TextBoxes and Images. 

'First I declare the Items
Dim Items() as Object

'Here is an Example of the ComboBox Properties Class:
<Serializable()> Public Class ComboBox_Properties
    ' Class declarations
    Private vBackColor As Color
    Private vForeColor As Color
    Private vType As String

    'Hold the name of the combobox for later use
    Public Property ItemType() As String
        Get
            ItemType = vType
        End Get
        Set(ByVal Value As String)
            vType = Value
        End Set
    End Property

    'Holds the backcolor of the control
    Public Property BackColor() As Color
        Get
            BackColor = vBackColor
        End Get
        Set(ByVal Value As Color)
            vBackColor = Value
        End Set
    End Property

End Class

'My Master Skin File reading routine determines which array 
'element must be assigned to which Class.
Items(Window)(ControlNum) = New ComboBox_Properties()

Now lets say the user has finished designing the window and want to test it, so he/she will invoke the routine that will create the skin file and test it within the window. In this routine I need to make an exact copy of the array to change the image filenames to something more appropiate.

This is where I hit a roadblock because the cloned array is created as a reference type array and when I change the clone array it changes the origianal array. I have tried Copy and CopyTo, and Clone functions and nothing seems to work. If anybody has any ideas they would be greatly appreciated, thanks!
 
Visual Basic: 
        Dim aray() As String ={"jon", "cindy", "nicholas", "alex", "nathan"}
        Dim newarray(5) As String
        Array.Copy(aray, newarray, 5)

        newarray(0) = "fred"

        Debug.WriteLine(newarray(0).ToString()) 'result will be fred
        Debug.WriteLine(aray(0).ToString) 'result will still be jon

This method produces a new array with the elements in the source array. Changing the elements in the new array does not affect the source arrays elements.

What you were looking for?


Jon
 
What I am having a problem with is after I copy the array and change a property of the copied array, it also changes the original array which I do not want. I think it is due to the array being an object array but I am not sure.
 
Re: How this thing works

JCreationsInc said:


Visual Basic: 
'I have a couple of classes the hold properties of various items such as 
'ComboBoxes, TextBoxes and Images. 

'First I declare the Items
Dim Items() as Object
Dim TestItems() as Object

'Here is an Example of the ComboBox Properties Class:
<Serializable()> Public Class ComboBox_Properties
    ' Class declarations
    Private vBackColor As Color
    Private vForeColor As Color
    Private vType As String

    'Hold the name of the combobox for later use
    Public Property ItemType() As String
        Get
            ItemType = vType
        End Get
        Set(ByVal Value As String)
            vType = Value
        End Set
    End Property

    'Holds the backcolor of the control
    Public Property BackColor() As Color
        Get
            BackColor = vBackColor
        End Get
        Set(ByVal Value As Color)
            vBackColor = Value
        End Set
    End Property

End Class

'My Master Skin File reading routine determines which array 
'element must be assigned to which Class.
Items(Window)(ControlNum) = New ComboBox_Properties()
Array.Copy(Items, TestItems, Items.GetUpperBound(0)) 'Now TestItems contains all the 
'elements of Items but changing the elements of TestItems will not effect the elements of Items.
' Use TestItems where you would use Items to test the skin.

B]
Click to expand...
 
May be I don't know what I am talking about. But why don't you define another array of the same type. Make it equal to your array. Won't the two array be then distinct from each other?
 
I started with one textbox (textbox1), generated two arrays obj1 and obj2, defined obj1, then made obj2's accessible role same as obj1's. Seemed to work. Obj1 was unaffected by what I did to Obj2. Is this what you are trying to do?

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim Obj1(3), obj2(3) As TextBox, i As Integer
For i = 0 To 3
Obj1(i) = New TextBox()
Obj1(i).AccessibleRole = TextBox1.AccessibleRole
Obj1(i).Left = 200 + 100 * i
Obj1(i).Top = 200
Obj1(i).Text = "testing"
Controls.Add(Obj1(i))
Obj1(i).Visible = True
Obj1(i).BackColor = Color.Green
Obj1(i).ForeColor = Color.White
Next i
For i = 0 To 3
obj2(i) = New TextBox()
obj2(i).AccessibleRole = Obj1(i).AccessibleRole
obj2(i).Left = 200 + 100 * i
obj2(i).Top = 300
obj2(i).Text = "tested"
Controls.Add(obj2(i))
obj2(i).Visible = True
obj2(i).BackColor = Color.Red
obj2(i).ForeColor = Color.White
Next i
End Sub
 
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