C＃WPF无法写入XML文件

Question

我是WPF的新手，正在尝试将子节点写入XML文件。这是文件...

<?xml version="1.0" encoding="utf-8"?>

<Sequences>

  <LastSavedSequence name="Last Saved Sequence">    

     <Test name="Measure Battery Current(Stim)" testNumber="5" Vbat="3.7" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>

     <Test name="Measure Batther Current(No Stim)" testNumber="6" Vbat="2.9" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>

  </LastSavedSequence>  

  <ScottTestSequence name="Scott Test Sequence">    

     <Test name="VMO Status" testNumber="4" Vbat="3.7" Frequency="20" PulseWidth="1000" Amplitude="6" Resistance="3000" Anode="1" Cathode="2" ActiveDischarge=""/>

     <Test name="Measure Battery Current(Stim)" testNumber="5" Vbat="3.7" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>

     <Test name="Measure Batther Current(No Stim)" testNumber="6" Vbat="2.9" Frequency="20" PulseWidth="500" Amplitude="1" Resistance="1600" Anode="1" Cathode="2" ActiveDischarge=""/>

  </ScottTestSequence>  

</Sequences>

我正在尝试创建要放入其中的XML子块。我使用了stringBuilder，然后尝试做一个附加子项，然后是一个.save。XMLData2是一个全局列表，包含每个子元素的子元素。这是我的代码...

public static List<System.Xml.XmlNode> xmlData2 = new List<System.Xml.XmlNode>();

XmlDocument xmlFromOutSideSequenceFile = new XmlDocument();

                    xmlFromOutSideSequenceFile.Load("c:\\Users/StarkS02/Documents/SavedSequenceFile.xml");

StringBuilder exampleNode = new StringBuilder();

                        exampleNode.Append("<");

我在.appendChild语句上收到编译器错误，无法将stringBuilder转换为XML节点。这很有道理，但我不确定如何解决。有任何想法吗？