Question

I’m trying to do something, that may be extremely simple so please bear with me, I just want to get ‘DisplayName’ from an XML file into a string in my C# code. here’s what I have:

THIS IS C#2.0 in VS2005

XML:

<MonitorScope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" id="System" xmlns="http://tempuri.org/XMLSchema.xsd">
    <PersonalSafety>    
<MonitorResponseRecord Enabled="false" DisplayName="ValveFailureAtCentralPosition">
<ExpressionMonitor>
<postAlarm>
<AlarmName>Valve_Position_Fault</AlarmName>
<Parameter1> Sensor Position = {X}</Parameter1>
<Parameter2> Sensor Position = {X}</Parameter2>
<Parameter3> Sensor Position = {X}</Parameter3>
</postAlarm>
</ExpressionMonitor>
</MonitorResponseRecord>
<MonitorResponseRecord ...  ... ...>
... ...
... ... and so on about 1600 times.

In my C# code I’ve attempted the following but to No Avail:
C#:

public class AlarmRecord
{
    /// <remarks/>
    public string PmAlarm;

    /// <remarks/>
    public string Parameter1;

    /// <remarks/>
    public string Parameter2;

    /// <remarks/>
    public string Parameter3;

    /// <remarks/>
    public string DisplayName;
}

    protected void OnPostAlarm(PostAlarm postAlarm)
    {
        try 
        {
            AlarmRecord alarmRecord = new AlarmRecord(); 
            alarmRecord.PmAlarm    = postAlarm.AlarmName;
            alarmRecord.Parameter1 = postAlarm.Parameter1;
            alarmRecord.Parameter2 = postAlarm.Parameter2;
            alarmRecord.Parameter3 = postAlarm.Parameter3;
            
            string fileName = "UMSM.009.8Root.xml";
            string fullPath;
            fullPath = Path.GetFullPath(fileName);

            XmlTextReader reader = new XmlTextReader(new StringReader(fullPath));
            System.Xml.XPath.XPathDocument docNav = new System.Xml.XPath.XPathDocument(reader);

            System.Xml.XPath.XPathNavigator Q = docNav.CreateNavigator();
            System.Xml.XPath.XPathExpression EXE = Q.Compile("MonitorResponseRecord/@DisplayName");
            alarmRecord.DisplayName = Convert.ToString(Q.Evaluate(EXE));
             alarms.Enqueue( alarmRecord ); 
        }
        catch (Exception e)
        {
            Log.Write(e);
            OnUnknownResponse(postAlarm);
        }
    }

basically my current issue is that durring Debug the issue that I’m noticing is in the line where ‘reader’ is initialized… the program usually throws an exception here

Answer 1

You could use an XmlReader:

    protected void OnPostAlarm(PostAlarm postAlarm) 
    {
       AlarmRecord record = null;
       List<AlarmRecord> recordList = new List<AlarmRecord>();

        using(XmlReader reader = XmlReader.Create("Xml/bin/UMSM.009.8Root.xml"))
        {

            while (reader.Read())
            {
                if (reader.NodeType == XmlNodeType.Element)
                {
                    switch (reader.Name)
                    {
                        case "MonitorResponseRecord":
                            record = new AlarmRecord();
                            recordList.Add(record);
                            reader.MoveToAttribute("DisplayName");
                            record.DisplayName = reader.Value;
                            break;

                        case "AlarmName":
                            record.PmAlarm = reader.ReadString();
                            break;

                        case "Parameter1":
                            record.Parameter1 = reader.ReadString();
                            break;

                        case "Parameter2":
                            record.Parameter2 = reader.ReadString();
                            break;

                        case "Parameter3":
                            record.Parameter3 = reader.ReadString();
                            break;
                    }
                }
            }
        }