Object Reference is Not Set to an Instance of an O

blackinwhite · January 26th, 2005, 02:48 AM

Dear all,

I am trying to write and better my skills coding some small junk of codes.

With the example codes from MSDN I have managed to write the below code in order to edit some selected node from an xml file.

But the below code gives me an error unexpectedly. :(

It says Object Reference is Not Set to an Instance of an Object at the line highlighted below.

I think root or id returns null.

can anyone help me about this.

Code:

 

Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        'Try
            'Send updates to xml file
        Dim xDoc As XmlDocument = New XmlDocument()
        Dim root As XmlNode = xDoc.DocumentElement
        Dim id As XmlNode
        Dim i As Integer
        'root = xDoc.DocumentElement

            For i = 0 To root.ChildNodes.Count - 1
                id = root.ChildNodes(i).Attributes("CustomerID")
                If (id.InnerText = txtUniqueID.Text) Then
                    xDoc.DocumentElement("CustomerID").Value = txtUniqueID.Text
                    xDoc.DocumentElement("CompanyName").Value = txtCoName.Text
                    xDoc.DocumentElement("ContactName").Value = txtContact.Text
                    xDoc.DocumentElement("ContactTitle").Value = txtTitle.Text
                    xDoc.DocumentElement("Address1").Value = txtAddress.Text
                    xDoc.DocumentElement("Phone1").Value = txtPhone1.Text
                    xDoc.DocumentElement("Phone2").Value = txtPhone2.Text
                    xDoc.DocumentElement("reason").Value = txtservice.Text
                End If
            Next i
        xDoc.Save(m_connCustomers)

        'Reset and begin again
        LoadDataSet()
        MsgBox("Record has been updated.")
        'Attempt to update the datasource.
        Me.LoadDataSet()
        'Catch eUpdate As System.Exception
        '    'Add your error handling code here.
        '    'Display error message, if any.
        '    System.Windows.Forms.MessageBox.Show(eUpdate.Message)
        'End Try
        Me.dsCust_PositionChanged()
    End Sub

Best,

Santhi · January 27th, 2005, 02:34 PM

You havent loaded the XML Document in the function.

blackinwhite · February 1st, 2005, 03:52 AM

how can i do it?

can you point me an example?

best,

Santhi · February 1st, 2005, 05:01 AM

Dim xDoc As XmlDocument = New XmlDocument()
xDoc.Load("XmlFileName")

blackinwhite · February 1st, 2005, 05:42 AM

thanks a million.
best,