Xmldoc.load 给出的对象引用未设置为对象的实例

Question

我有一个包含 XML 的字符串。我想从中创建一个 XML 文档。我正在使用 Load 和 LoadXMl 方法，如下所示：

   Dim doc As XmlDocument
            doc.LoadXml(applicationXml)

但他们正在重新调整：

Object reference not set to an instance of an object.

我的 XML 看起来像这样：

<gate.util.persistence.GateApplication>
  <urlList class="gate.util.persistence.CollectionPersistence">
    <localList>      
      <gate.util.persistence.PersistenceManager-URLHolder>
        <urlString>$gatehome$plugins/LingPipe/</urlString>
      </gate.util.persistence.PersistenceManager-URLHolder>
      <gate.util.persistence.PersistenceManager-URLHolder>
        <urlString>$gatehome$plugins/ANNIE/</urlString>
      </gate.util.persistence.PersistenceManager-URLHolder>
      <gate.util.persistence.PersistenceManager-URLHolder>
        <urlString>$gatehome$plugins/Stemmer_Snowball/</urlString>
      </gate.util.persistence.PersistenceManager-URLHolder>     
    </localList>
    <collectionType>java.util.ArrayList</collectionType>
  </urlList>
  <application class="gate.util.persistence.SerialAnalyserControllerPersistence">
    <prList class="gate.util.persistence.CollectionPersistence">
      <localList>
        <gate.util.persistence.PRPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>setsToKeep</string>
                <null />
              </entry>
              <entry>
                <string>document</string>
                <null/>
              </entry>
              <entry>
                <string>annotationTypes</string>
                <null/>
              </entry>
              <entry>
                <string>corpus</string>
                <null/>
              </entry>
              <entry>
                <string>keepOriginalMarkupsAS</string>
                <boolean>true</boolean>
              </entry>
              <entry>
                <string>setsToRemove</string>
                <null/>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>gate.creole.annotdelete.AnnotationDeletePR</resourceType>
          <resourceName>Document Reset PR</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </initParams>
          <features class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </features>
        </gate.util.persistence.PRPersistence>
        <gate.util.persistence.LanguageAnalyserPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>annotationSetName</string>
                <null/>
              </entry>
              <entry>
                <string>document</string>
                <null/>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>gate.creole.tokeniser.DefaultTokeniser</resourceType>
          <resourceName>ANNIE English Tokeniser</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>tokeniserRulesURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/tokeniser/DefaultTokeniser.rules</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
              <entry>
                <string>transducerGrammarURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/tokeniser/postprocess.jape</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
              <entry>
                <string>encoding</string>
                <string>UTF-8</string>
              </entry>
            </localMap>
          </initParams>
          <features class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </features>
        </gate.util.persistence.LanguageAnalyserPersistence>
        <gate.util.persistence.LanguageAnalyserPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>annotationSetName</string>
                <null/>
              </entry>
              <entry>
                <string>document</string>
                <null/>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>com.ontotext.gate.gazetteer.HashGazetteer</resourceType>
          <resourceName>TCG Gazetteer</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>listsURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>http://halo.dyndns-web.com:96/tcg/GATE/Gazetteers/MasterListsDef.def</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
              <entry>
                <string>encoding</string>
                <string>UTF-8</string>
              </entry>
              <entry>
                <string>caseSensitive</string>
                <boolean>false</boolean>
              </entry>
            </localMap>
          </initParams>
          <features class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </features>
        </gate.util.persistence.LanguageAnalyserPersistence>
        <gate.util.persistence.LanguageAnalyserPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>wholeWordsOnly</string>
                <boolean>true</boolean>
              </entry>
              <entry>
                <string>document</string>
                <null/>
              </entry>
              <entry>
                <string>longestMatchOnly</string>
                <boolean>true</boolean>
              </entry>
              <entry>
                <string>annotationSetName</string>
                <null/>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>gate.creole.gazetteer.DefaultGazetteer</resourceType>
          <resourceName>ANNIE Gazetteer</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>gazetteerFeatureSeparator</string>
                <null/>
              </entry>
              <entry>
                <string>listsURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/gazetteer/lists.def</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
              <entry>
                <string>caseSensitive</string>
                <boolean>true</boolean>
              </entry>
              <entry>
                <string>encoding</string>
                <string>UTF-8</string>
              </entry>
            </localMap>
          </initParams>
          <features class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </features>
        </gate.util.persistence.LanguageAnalyserPersistence>
        <gate.util.persistence.LanguageAnalyserPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>outputASName</string>
                <null/>
              </entry>
              <entry>
                <string>document</string>
                <null/>
              </entry>
              <entry>
                <string>inputASName</string>
                <null/>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>gate.creole.splitter.SentenceSplitter</resourceType>
          <resourceName>ANNIE Sentence Splitter</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>encoding</string>
                <string>UTF-8</string>
              </entry>
              <entry>
                <string>gazetteerListsURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/sentenceSplitter/gazetteer/lists.def</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
              <entry>
                <string>transducerURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/sentenceSplitter/grammar/main.jape</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
            </localMap>
          </initParams>
          <features class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </features>
        </gate.util.persistence.LanguageAnalyserPersistence>
        <gate.util.persistence.LanguageAnalyserPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>document</string>
                <null/>
              </entry>
              <entry>
                <string>corpus</string>
                <null/>
              </entry>
              <entry>
                <string>outputAnnotationType</string>
                <string>Token</string>
              </entry>
              <entry>
                <string>inputASName</string>
                <null/>
              </entry>
              <entry>
                <string>failOnMissingInputAnnotations</string>
                <boolean>true</boolean>
              </entry>
              <entry>
                <string>outputASName</string>
                <null/>
              </entry>
              <entry>
                <string>baseSentenceAnnotationType</string>
                <string>Sentence</string>
              </entry>
              <entry>
                <string>baseTokenAnnotationType</string>
                <string>Token</string>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>gate.creole.POSTagger</resourceType>
          <resourceName>ANNIE POS Tagger</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>encoding</string>
                <null/>
              </entry>
              <entry>
                <string>rulesURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/heptag/ruleset</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
              <entry>
                <string>lexiconURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/heptag/lexicon</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
            </localMap>
          </initParams>
          <features class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </features>
        </gate.util.persistence.LanguageAnalyserPersistence>
        <gate.util.persistence.LanguageAnalyserPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>outputASName</string>
                <null/>
              </entry>
              <entry>
                <string>document</string>
                <null />
              </entry>
              <entry>
                <string>inputASName</string>
                <null/>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>gate.creole.ANNIETransducer</resourceType>
          <resourceName>ANNIE NE Transducer</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>encoding</string>
                <string>UTF-8</string>
              </entry>
              <entry>
                <string>annotationAccessors</string>
                <null/>
              </entry>
              <entry>
                <string>operators</string>
                <null/>
              </entry>
              <entry>
                <string>grammarURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/NE/main.jape</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
            </localMap>
          </initParams>
          <features class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap/>
          </features>
        </gate.util.persistence.LanguageAnalyserPersistence>
        <gate.util.persistence.LanguageAnalyserPersistence>
          <runtimeParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>annotationSetName</string>
                <null/>
              </entry>
              <entry>
                <string>document</string>
                <null/>
              </entry>
              <entry>
                <string>annotationTypes</string>
                <gate.util.persistence.CollectionPersistence>
                  <localList>
                    <string>Organization</string>
                    <string>Person</string>
                    <string>Location</string>
                    <string>Date</string>
                  </localList>
                  <collectionType>java.util.ArrayList</collectionType>
                </gate.util.persistence.CollectionPersistence>
              </entry>
            </localMap>
          </runtimeParams>
          <resourceType>gate.creole.orthomatcher.OrthoMatcher</resourceType>
          <resourceName>ANNIE OrthoMatcher</resourceName>
          <initParams class="gate.util.persistence.MapPersistence">
            <mapType>gate.util.SimpleFeatureMapImpl</mapType>
            <localMap>
              <entry>
                <string>definitionFileURL</string>
                <gate.util.persistence.PersistenceManager-URLHolder>
                  <urlString>$gatehome$plugins/ANNIE/resources/othomatcher/listsNM.def</urlString>
                </gate.util.persistence.PersistenceManager-URLHolder>
              </entry>
              <entry>
                <string>minimumNicknameLikelihood</string>
                <double>0.5</double>
              </entry>
              <entry>
                <string>extLists</string>
                <boolean>true</boolean>
              </entry>
              <entry>
                <string>encoding</string>
                <string>UTF-8</string>
              </entry>
              <entry>

    

Answer 1

似乎您需要使用New关键字，因为它XmlDocument是一种引用类型：

  Dim doc as XmlDocument = new XmlDocument()

有关更多详细信息，请参阅http://msdn.microsoft.com/en-us/library/system.xml.xmldocument.loadxml.aspx#Y0。