deserialize streamReader as Observablecollection

Question

Hope someone can help me resolve below error.

<The thread '<No Name>' (0x1d2c) has exited with code 0 (0x0).

A first chance exception of type 'System.InvalidOperationException' occurred in System.Xml.dll

Step into: Stepping over non-user code 'MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen>

This error occurs when I try to deserialize streamReader as Observablecollection. See code below:

class InstrumentListViewModel
    {
        private ObservableCollection<Instrument> _InstrumentList = new ObservableCollection<Instrument>();
        
        
        public ObservableCollection<Instrument> InstrumentList
        {
            get { return _InstrumentList; }
            set {_InstrumentList = value;}
        }
                
        public InstrumentListViewModel()
        {
            XmlSerializer xs = new XmlSerializer(typeof(ObservableCollection<Instrument>));
            
            using (StreamReader sr = new StreamReader(@"C:\Instruments.xml"))
            {
                InstrumentList = xs.Deserialize(sr) as ObservableCollection<Instrument>;
            }
        }
    }

<?xml version="1.0" encoding="utf-8"?>
<Instruments>
  <Instrument>
    <Alias>Source1"</Alias>
    <Type>Source</Type>
    <InterfaceID>0</InterfaceID>
    <IterfaceType>GPIB</IterfaceType>
    <Address>9</Address>
    <Slot></Slot>
    <SerialNumber></SerialNumber>
    <CalibrationDate></CalibrationDate>
  </Instrument>
  <Instrument>
    <Alias>Load1"</Alias>  
    <Type>Load</Type>
    <InterfaceID>0</InterfaceID>
      <IterfaceType>GPIB</IterfaceType>
      <Address>10</Address>
      <Slot></Slot>
      <SerialNumber>1234</SerialNumber>
      <CalibrationDate></CalibrationDate>
   </Instrument>
</Instruments>		

public class Instrument //: ObservableObject, IComparable<Instrument>  
    {
        public enum InstrumentType { Source, Load, Oscilloscope, TemperatureChamber, PowerMeter, DVM,DataAcqSwitchUnit, DACCard, Thermometer,FunctionGenerator, LCRMeter}
        public enum InstrumentInterface { GPIB,USB,ASRL}
        
        // The following properties are wrapping an array of strings
        [Category("Common")]
        [DisplayName("Type")]
        public InstrumentType Type {get; set;}
        [Category("Common")]
        [DisplayName("Alias")]
        public string Alias { get; set; }
        [Category("Interface")]
        [DisplayName("Interface Type")]
        public InstrumentInterface IterfaceType { get; set; }
        [Category("Interface")]
        [DisplayName("Interface ID")]
        [Description("Numerical value of 0 through 30.")]
        public int InterfaceID { get; set; }
        [Category("Interface")]
        [DisplayName("Address")]
        [Description("Enter Instrument Address")]
        public string Address { get; set; }
        [Category("Interface")]
        [DisplayName("Slot")]
        [Description("Enter appropriate Channel, Bay, or slot position.")]
        public int Slot { get; set; }
        [Category("Other")]
        [DisplayName("Serial Number")]
        public string SerialNumber { get; set; }
        [Category("Other")]
        [DisplayName("Calibration Date")]
        public string CalibrationDate { get; set; }
}

Thanks,

Wes

---

wesley

Answer 1

Figured it out. Made changes to xml file.

In root node, changed <Instruments> to <ArrayOfInstrument> and all child nodes must contain a value.

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfInstrument>
  <Instrument>
    <Alias>Source1"</Alias>
    <Type>Source</Type>
    <InterfaceID>0</InterfaceID>
    <IterfaceType>GPIB</IterfaceType>
    <Address>9</Address>
    <Slot>0</Slot>
    <SerialNumber>0</SerialNumber>
    <CalibrationDate>0</CalibrationDate>
  </Instrument>
  <Instrument>
    <Alias>Load1"</Alias>
    <Type>Load</Type>
    <InterfaceID>0</InterfaceID>
    <IterfaceType>GPIB</IterfaceType>
    <Address>10</Address>
    <Slot>0</Slot>
    <SerialNumber>1234</SerialNumber>
    <CalibrationDate>0</CalibrationDate>
  </Instrument>
</ArrayOfInstrument>

Answer 2

Good

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NEU_ShieldEdge

Answer 3

Is it possible not to use ArrayOf?

---

wesley