c# – XDocument Root.Elements()返回null

这里是xml的一个示例：

<?xml version="1.0" encoding="UTF-8"?>
<TestRun id="2ece436d-907d-4f59-9c81-0544b2f4f7cd" name="redacted" runUser="redacted" xmlns="http://microsoft.com/scheR_113_11845@as/Visualstudio/TeamTest/2010">
  <TestSetTings name="Default Test SetTings" id="e00bb4af-1518-4b40-9905-19fa7b190f68">
    ... 
  </TestSetTings>
  <Times creation="2015-02-18T11:47:02.7188640-05:00" queuing="2015-02-18T11:47:03.1819103-05:00" start="2015-02-18T11:47:03.2819203-05:00" finish="2015-02-18T11:47:05.5571478-05:00" />
  <ResultSumMary outcome="Failed">
    <Counters @R_227_10586@l="74" executed="74" passed="73" error="0" Failed="1" timeout="0" aborted="0" inconclusive="0" passedButRunAborted="0" notRunnable="0" notExecuted="0" disconnected="0" warning="0" completed="0" inProgress="0" pending="0" />
  </ResultSumMary>

我想要检索< ResultSumMary>的结果,但是对xml.Root的所有Element()和Elements()调用都返回null.

var xml = XDocument.Load(resultFilE);
var outcome = xml.Root
    .Element("TestRun")
    .Element("ResultSumMary")
    .Attribute("outcome")
    .Value;

我尝试添加像this answer中的命名空间,但我仍然得到相同的结果：

var xml = XDocument.Load(resultFilE);
XNamespace ns = "http://microsoft.com/scheR_113_11845@as/Visualstudio/TeamTest/2010";
var outcome = xml.Root
    .Element(ns + "TestRun")
    .Element("ResultSumMary")
    .Attribute("outcome")
    .Value;

另外,我不确定Root是否应该返回< TestRun>我是否尝试过运行xml.Root.Element(“ResultSumMary”),我仍然得到null.

我该如何阅读这个xml文件？