Error while creating XML Document : XML document must have a top level element

Question

I'm trying to serialize the object below and get the following error when creating the xml file.
XML document must have a top level element. Error processing resource

It works when there is just one instance in the collection. Can anyone help me with this?

[Serializable]
    public class Processes
    {
        string pvtProcessesName = "";

List<ProcessAttribute> pvtPros = new List<ProcessAttribute>(0);

        public Processes()
        {

        }

        public string ProcessesName
        {
            get { return pvtProcessesName; }
            set { pvtProcessesName = value; }
        }

        public List<ProcessAttribute> All_Processes
        {
            get { return pvtPros; }
            set { pvtPros = value; }
        }

        public void Add(ProcessAttribute pAtt)
        {
            pvtPros.Add(pAtt);
        }

    }

The above object has a collection of the below object

[Serializable]
    public class ProcessAttribute
    {
        string pvtName = "";

List<NodeAttributes> pvtNodes = new List<NodeAttributes>(0);

        public ProcessAttribute()
        {

        }

        public string ProcessName
        {
            get { return pvtName; }
            set { pvtName = value; }
        }

        public List<NodeAttributes> Nodes
        {
            get { return pvtNodes; }
            set { pvtNodes = value; }
        }

        public void Add(NodeAttributes nd)
        {
            pvtNodes.Add(nd);
        }

}

NodeAttributes is a class with variables with get and set methods.
How can I solve the problem

Jan Montano · Answer

How are you populating the actual objects? This is what I've got so far. No errors yet private void button5_Click(object sender EventArgs e) { XmlDocument xmlDocument = new XmlDocument(); XmlSerializer serializer = new XmlSerializer(typeof(Processes)); XmlTextWriter xmlWriter = new XmlTextWriter(@G:\Temp	emp1.xmlEncoding.ASCII); Processes processes = new Processes(); NodeAttributes nodeAttributes1 = new NodeAttributes(); NodeAttributes nodeAttributes2 = new NodeAttributes(); ProcessAttribute processAttribute1 = new ProcessAttribute(); ProcessAttribute processAttribute2 = new ProcessAttribute(); processAttribute1.Add(nodeAttributes1); processAttribute1.Add(nodeAttributes2); processAttribute2.Add(nodeAttributes1); processAttribute2.Add(nodeAttributes2); processes.Add(processAttribute1); processes.Add(processAttribute2); serializer.Serialize(xmlWriterprocesses); }

thavs · Answer

Here is the NodeAattributes class. I'm using it to store properties of a flowchart node. trying to create an xml file of the flowchart. public class NodeAttributes { // private members string pvt_strProcessName = Process Name ; string pvt_strName = Node Name ; string pvt_Level = Level ; string pvt_Group = Group ; string pvt_Location = Location ; string pvt_strUserAlloc = User1 ; string pvt_Form = Form1 ; string pvt_ActionReq = Action ; string pvt_strOption = Option1 ; string pvt_strReminder = 0 ; string pvt_strMaximum = 0 ; bool pvt_strEscalate = true ; bool pvt_strLogStats = true ; Node pvtNode = null ; // public accessors [ CategoryAttribute ( Description ) DefaultValueAttribute ( Process ) ReadOnly ( true )] public string ProcessName{ get { return pvt_strProcessName; } set { pvt_strProcessName = value ; } } [ CategoryAttribute ( Description ) DefaultValueAttribute ( Node Name )] public string Name{ get { return pvt_strName; } set { pvt_strName = value ; }} [ CategoryAttribute ( Task Allocation ) TypeConverter ( typeof (Levels))] public string Level{ get { return pvt_Level; } set { pvt_Level = value ; }} [ CategoryAttribute ( Task Allocation ) TypeConverter ( typeof (Groups))] public string Group{ get { return pvt_Group; } set { pvt_Group = value ; }} [ CategoryAttribute ( Task Allocation ) TypeConverter ( typeof (Locations))] public string Location{ get { return pvt_Location; } set { pvt_Location = value ; }} [ CategoryAttribute ( Allocation Type ) DefaultValueAttribute ( First User )] public string UserAlloc{ get { return pvt_strUserAlloc; } set { pvt_strUserAlloc = value ; }} [ CategoryAttribute ( Visual Options ) TypeConverter ( typeof (Forms))] public string Form{ get { return pvt_Form; } set { pvt_Form = value ; }} [ CategoryAttribute ( Visual Options ) TypeConverter ( typeof (Actions ))] public string ActionReq{ get { return pvt_ActionReq; } set { pvt_ActionReq = value ; }} [ CategoryAttribute ( Visual Options ) TypeConverter ( typeof (Options))] public string Option{ get { return pvt_strOption; } set { pvt_strOption = value ; }} [ CategoryAttribute ( Non-Action ) DefaultValueAttribute ( Reminder )] public string Reminder{ get { return pvt_strReminder; } set { pvt_strReminder = value ; }} [ CategoryAttribute ( Non-Action ) DefaultValueAttribute ( Maximum )] public string Maximum{ get { return pvt_strMaximum; } set { pvt_strMaximum = value ; }} public bool Escalate{ get { return pvt_strEscalate; } set { pvt_strEscalate = value ; }} public bool LogStats{ get { return pvt_strLogStats; } set { pvt_strLogStats = value ; }} public Node PNode{ get { return pvtNode; } set { pvtNode = value ; }} public class Groups : StringConverter { private static ArrayList groups = new ArrayList (); private string [] gps = new string [10]; public void GetGroups() { SqlConnection conn = new SqlConnection ( ConfigurationSettings .AppSettings[ Connection ].ToString()); SqlCommand cmd = new SqlCommand ( Select * from Groups  conn); SqlDataReader rd = null ; conn.Open(); groups.Clear(); rd = cmd.ExecuteReader(); int i = 0; int gID = 0; string gDesc =  ; while (rd.Read()) { gID = Convert .ToInt32(rd.GetValue(0)); gDesc = Convert .ToString(rd.GetValue(1)); Data d = new Data (gID gDesc); groups.Add(d); gps[i] = gDesc; i += 1; } rd.Close(); conn.Close(); } public override bool GetStandardValuesSupported( ITypeDescriptorContext context) { return true ; } public override StandardValuesCollection GetStandardValues( ITypeDescriptorContext context) { GetGroups(); return new StandardValuesCollection (gps); } public override bool GetStandardValuesExclusive( ITypeDescriptorContext context) { return false ; } } public class Levels : StringConverter { private static ArrayList levels = new ArrayList (); private string [] ls = new string [10]; public void GetLevels() { SqlConnection conn = new SqlConnection ( ConfigurationSettings .AppSettings[ Connection ].ToString()); SqlCommand cmd = new SqlCommand ( Select * from Levels  conn); SqlDataReader rd = null ; conn.Open(); rd = cmd.ExecuteReader(); levels.Clear(); int i = 0; int ID = 0; string Desc =  ; while (rd.Read()) { ID = Convert .ToInt32(rd.GetValue(0)); Desc = Convert .ToString(rd.GetValue(1)); Data d = new Data ( Convert .ToInt32(rd.GetValue(0)) Convert .ToString(rd.GetValue(1))); levels.Add(d); ls[i] = Desc; i += 1; } rd.Close(); conn.Close(); } public override bool GetStandardValuesSupported( ITypeDescriptorContext context) { return true ; } public override StandardValuesCollection GetStandardValues( ITypeDescriptorContext context) { GetLevels(); return new StandardValuesCollection (ls); } public override bool GetStandardValuesExclusive( ITypeDescriptorContext context) { return false ; } } public class Locations : StringConverter { private static ArrayList locations = new ArrayList (); private string [] locs = new string [10]; public void GetLocations() { SqlConnection conn = new SqlConnection ( ConfigurationSettings .AppSettings[ Connection ].ToString()); SqlCommand cmd = new SqlCommand ( SELECT LocationIDDescription FROM Locations  conn); SqlDataReader rd = null ; conn.Open(); rd = cmd.ExecuteReader(); locations.Clear(); int i = 0; int ID = 0; string Desc =  ; while (rd.Read()) { ID = Convert .ToInt32(rd.GetValue(0)); Desc = Convert .ToString(rd.GetValue(1)); Data d = new Data ( Convert .ToInt32(rd.GetValue(0)) Convert .ToString(rd.GetValue(1))); locations.Add(d); locs[i] = Desc; i += 1; } rd.Close(); conn.Close(); } public override bool GetStandardValuesSupported( ITypeDescriptorContext context) { return true ; } public override StandardValuesCollection GetStandardValues( ITypeDescriptorContext context) { GetLocations(); return new StandardValuesCollection (locs); } public override bool GetStandardValuesExclusive( ITypeDescriptorContext context) { return false ; } } public class Forms : StringConverter { private static ArrayList forms = new ArrayList (); private string [] frms = new string [10]; public void GetForms() { SqlConnection conn = new SqlConnection ( ConfigurationSettings .AppSettings[ Connection ].ToString()); SqlCommand cmd = new SqlCommand ( Select * from GetForms  conn); SqlDataReader rd = null ; conn.Open(); rd = cmd.ExecuteReader(); forms.Clear(); int i = 0; int ID = 0; string Desc =  ; while (rd.Read()) { ID = Convert .ToInt32(rd.GetValue(0)); Desc = Convert .ToString(rd.GetValue(1)); Data d = new Data ( Convert .ToInt32(rd.GetValue(0)) Convert .ToString(rd.GetValue(1))); forms.Add(d); frms[i] = Desc; i += 1; } rd.Close(); conn.Close(); } public override bool GetStandardValuesSupported( ITypeDescriptorContext context) { return true ; } public override StandardValuesCollection GetStandardValues( ITypeDescriptorContext context) { GetForms(); return new StandardValuesCollection (frms); } public override bool GetStandardValuesExclusive( ITypeDescriptorContext context) { return false ; } } public class Actions : StringConverter { private static ArrayList actions = new ArrayList (); private string [] acts = new string [10]; public void GetActions() { SqlConnection conn = new SqlConnection ( ConfigurationSettings .AppSettings[ Connection ].ToString()); SqlCommand cmd = new SqlCommand ( Select * from GetActions where REQ=1  conn); SqlDataReader rd = null ; conn.Open(); rd = cmd.ExecuteReader(); actions.Clear(); int i = 0; int ID = 0; string Desc =  ; while (rd.Read()) { ID = Convert .ToInt32(rd.GetValue(0)); Desc = Convert .ToString(rd.GetValue(1)); Data d = new Data ( Convert .ToInt32(rd.GetValue(0)) Convert .ToString(rd.GetValue(1))); actions.Add(d); acts[i] = Desc; i += 1; } rd.Close(); conn.Close(); } public override bool GetStandardValuesSupported( ITypeDescriptorContext context) { return true ; } public override StandardValuesCollection GetStandardValues( ITypeDescriptorContext context) { GetActions(); return new StandardValuesCollection (acts); } public override bool GetStandardValuesExclusive( ITypeDescriptorContext context) { return false ; } } public class Options : StringConverter { private static ArrayList options = new ArrayList (); private string [] opts = new string [10]; public void GetOptions() { SqlConnection conn = new SqlConnection ( ConfigurationSettings .AppSettings[ Connection ].ToString()); SqlCommand cmd = new SqlCommand ( Select * from GetOptionGroups  conn); SqlDataReader rd = null ; conn.Open(); rd = cmd.ExecuteReader(); options.Clear(); int i = 0; int ID = 0; string Desc =  ; while (rd.Read()) { ID = Convert .ToInt32(rd.GetValue(0)); Desc = Convert .ToString(rd.GetValue(1)); Data d = new Data ( Convert .ToInt32(rd.GetValue(0)) Convert .ToString(rd.GetValue(1))); options.Add(d); opts[i] = Desc; i += 1; } rd.Close(); conn.Close(); } public override bool GetStandardValuesSupported( ITypeDescriptorContext context) { return true ; } public override StandardValuesCollection GetStandardValues( ITypeDescriptorContext context) { GetOptions(); return new StandardValuesCollection (opts); } public override bool GetStandardValuesExclusive( ITypeDescriptorContext context) { return false ; } } public class Data { private int id = 0; private string decription =  ; public Data( int i string d) { id = i; decription = d; } public int ID { get { return id; } set { id = value ; } } public string Description { get { return decription; } set { decription = value ; } } }

Jan Montano · Answer

Can we see your NodeAttributes class?