[RESOLVED] XSD, DataSet and a XML file.

[abhijit]

My requirement is to create a XML file based on an XSD.
The source data for this file will be coming from a database. For the purposes of this test, I am trying to manually assign the values.

I followed these steps:

1) Used the XSD.exe to create a VB Class.

xsd /d /l:VB emprec.xsd /n:XSDSchema.EmpCollection 

2) Added the VB Class in my project.
3) If I try to compile my code, I get an error.

Here's the code I wrote:

Private Sub cmdXML_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdXML.Click
        Dim emp As New EMPLOYEE_COLLECTION
        Dim empDataTable As New EMPLOYEE_COLLECTION.EMPLOYEE_RECORDDataTable
        Dim empDataRow As New EMPLOYEE_COLLECTION.EMPLOYEE_RECORDRow
 
        Dim empDataReader As DataTableReader = empDataTable.CreateDataReader()
 
        Dim x As Integer
 
        For x = 1 To 5
            empDataRow.EMPLOYEE_NO = "AISGM"
            empDataRow.FIRSTNAME = "Abhijit"
            empDataRow.LASTNAME = "IsGettingMad"
            empDataRow.NTID = "DONTGETMAD"
            empDataTable.AddEMPLOYEE_RECORDRow(empDataRow)
            empDataRow.ClearErrors()
        Next x

The error I get is

Error    1    First statement of this 'Sub New' must be a call to 'MyBase.New' or 'MyClass.New' because base class 'System.Data.DataRow' of 'writeXMLbasedonXSD.XSDSchema.EmpCollection.EMPLOYEE_COLLECTION.EMPLOYEE_RECORDRow' does not have an accessible 'Sub New' that can be called with no arguments.    D:\Visual Studio 2010\Projects\writeXMLbasedonXSD\writeXMLbasedonXSD\emprec.vb    598    17    writeXMLbasedonXSD 

This is the code from the class that was generated using XSD utility.

Partial Public Class EMPLOYEE_RECORDRow
            Inherits Global.System.Data.DataRow
 
            Private tableEMPLOYEE_RECORD As EMPLOYEE_RECORDDataTable
 
            <Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), _
             Global.System.CodeDom.Compiler.GeneratedCodeAttribute("System.Data.Design.TypedDataSetGenerator", "4.0.0.0")> _
            Friend Sub New(ByVal rb As Global.System.Data.DataRowBuilder)
                MyBase.New(rb)
                Me.tableEMPLOYEE_RECORD = CType(Me.Table, EMPLOYEE_RECORDDataTable)
            End Sub
 
            Sub New()
                ' TODO: Complete member initialization 
 
                'I AM UNABLE TO ADD ANY CODE HERE.
            End Sub
 
            <Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), _
             Global.System.CodeDom.Compiler.GeneratedCodeAttribute("System.Data.Design.TypedDataSetGenerator", "4.0.0.0")> _
            Public Property EMPLOYEE_NO() As String
                Get
                    Return CType(Me(Me.tableEMPLOYEE_RECORD.EMPLOYEE_NOColumn), String)
                End Get
                Set(ByVal value As String)
                    Me(Me.tableEMPLOYEE_RECORD.EMPLOYEE_NOColumn) = value
                End Set
            End Property
 
            <Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), _
             Global.System.CodeDom.Compiler.GeneratedCodeAttribute("System.Data.Design.TypedDataSetGenerator", "4.0.0.0")> _
            Public Property FIRSTNAME() As String
                Get
                    Return CType(Me(Me.tableEMPLOYEE_RECORD.FIRSTNAMEColumn), String)
                End Get
                Set(ByVal value As String)
                    Me(Me.tableEMPLOYEE_RECORD.FIRSTNAMEColumn) = value
                End Set
            End Property
 
            <Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), _
             Global.System.CodeDom.Compiler.GeneratedCodeAttribute("System.Data.Design.TypedDataSetGenerator", "4.0.0.0")> _
            Public Property LASTNAME() As String
                Get
                    Return CType(Me(Me.tableEMPLOYEE_RECORD.LASTNAMEColumn), String)
                End Get
                Set(ByVal value As String)
                    Me(Me.tableEMPLOYEE_RECORD.LASTNAMEColumn) = value
                End Set
            End Property
 
            <Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), _
             Global.System.CodeDom.Compiler.GeneratedCodeAttribute("System.Data.Design.TypedDataSetGenerator", "4.0.0.0")> _
            Public Property NTID() As String
                Get
                    Return CType(Me(Me.tableEMPLOYEE_RECORD.NTIDColumn), String)
                End Get
                Set(ByVal value As String)
                    Me(Me.tableEMPLOYEE_RECORD.NTIDColumn) = value
                End Set
            End Property
        End Class

How do I resolve this? I am unable to add any code in the 'TODO section for this generated class. What am I missing?

[techgnome]

I don't know why you "can't" but all you need in your New() constructor is "MyBase.New" ... because the class is inherited, you have to make sure you call the appropriate constructor of the inherited class.

-tg

[abhijit]

I don't know why you "can't" but all you need in your New() constructor is "MyBase.New" ... because the class is inherited, you have to make sure you call the appropriate constructor of the inherited class.

-tg

I tried to use MyBase.New() in the class, but it threw this error.

Error    1    Argument not specified for parameter 'builder' of 'Protected Friend Sub New(builder As System.Data.DataRowBuilder)'.    C:\\Projects\\writeXMLbasedonXSD\\writeXMLbasedonXSD\\emprec.vb    596    17    writeXMLbasedonXSD 

So I tried to correct it using this code
MyBase.New(builder as Global.System.Data.DataRowBuilder)
That throws up an error as well.

It seems I cannot use an object that has not been created yet.

[techgnome]

wait... does the class you are inheriting from even have a parameterless constructor?

Also, of course you can't use an object you haven't created... you can't drive a car that hasn't been built, can you? What you need to do is CREATE the instance of the object and pass it in.

But if the class you are inheriting from doesn't even have a parameterless constructor, then you can actually remove yours, and it should be OK.

-tg

[abhijit]

This is the code that works:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        Try
            Dim myEmpDS As New EMPLOYEE_COLLECTION.EMPLOYEE_RECORDDataTable
            Dim myempDsRow As EMPLOYEE_COLLECTION.EMPLOYEE_RECORDRow
'If I wish to loop, this is the place to do it.
            myempDsRow = myEmpDS.NewRow()
            myempDsRow.EMPLOYEE_NO = "ABHIJIT"
            myempDsRow.FIRSTNAME = "ABHIJIT"
            myempDsRow.LASTNAME = "ABHIJIT"
            myempDsRow.NTID = "ABHIJIT"
            myEmpDS.AddEMPLOYEE_RECORDRow(myempDsRow)
            myEmpDS.WriteXml("hello.xml")
        Catch ex As Exception
            MsgBox(ex.InnerException)
        End Try
    End Sub

[abhijit]

How do I serialize this?