User created control not working in form

[borri Craig]

I created a user control with a label and 2 combo boxes, and a public property called ControlDataSour ce that accepts a dataset - which it populates the combo boxes with. I added the reference to the VB project I want to use it on and to the toolbox. I was able to draw it on the form with no problem and use it. However, after changing the backcolor on the control and recompiling it, it is no longer seen by the form. When I bring up the form it's used on, I get a white screen with a bunch of xml. The problem seems to be in the designer, and I get an "object reference not set to an instance of an object" error. Here is the code from the designer:

        '
        'UcDx1
        '
        Me.UcDx1.AutoSize = True
        Me.UcDx1.AutoSizeMode = System.Windows.Forms.AutoSizeMode.GrowAndShrink
        Me.UcDx1.BackColor = System.Drawing.Color.Transparent
        Me.UcDx1.ControlDataSource = Nothing
        Me.UcDx1.LabelText = "Diag 1"
        Me.UcDx1.Location = New System.Drawing.Point(1, 259)
        Me.UcDx1.Margin = New System.Windows.Forms.Padding(0)
        Me.UcDx1.Name = "UcDx1"
        Me.UcDx1.SelectectedItemValue = ""
        Me.UcDx1.Size = New System.Drawing.Size(289, 29)
        Me.UcDx1.TabIndex = 3

The reference error is pointing to the line:

Me.UcDx1.ControlDataSource = Nothing

Here's the wierd part. If I hover the cursor over that property, it correctly identifies it as a dataset. So it does know what it is, but it can't seem to use it.

Any ideas would be appreciated.

[David Gluth]

Please post the ControlDataSour ce Property code block.

[borri Craig]

Here is the property control block:

    Private dTable As DataTable


    '<Description("Gets/Sets the dataset used by the dropdowns.")> _
    Public Property ControlCBODataSource() As DataSet
        Get
            ControlCBODataSource = dsSet
        End Get
        Set(ByVal value As DataSet)

            dsSet = value.Copy
            With cmbDX1
                .DataSource = dsSet.Tables(0)
                .DisplayMember = "DX"
                .ValueMember = "Description"
            End With

            With cmbDX1Desc
                .DataSource = dsSet.Tables(0)
                .DisplayMember = "Description"
                .ValueMember = "DX"
            End With
        End Set
    End Property

[David Gluth]

I played around with the info you gave and don’t see the problem, but then my implementation of your control is not producing the line me.UCDx1.Contro lDataSoruce = nothing. Obviously I am missing some of your code. Did you implement daSet as New Dataset?

Hope you get it figured out.