避免<item type>节点在C#中创建JSON到XML转换器

Question

我们试图使用以下C#代码将JSON转换为XML：

Object httpConn = Dts.Connections["HTTP"].AcquireConnection(null);
            HttpClientConnection myConnection = new HttpClientConnection(httpConn);
            myConnection.ServerURL = string.Format(("http://xxxx.com/jjjj"),"userid","password");
            byte[] webdata = myConnection.DownloadData();

            String result_data = Convert.ToBase64String(webdata);
            XmlDocument xd = new XmlDocument();
            XmlDictionaryReader xr = JsonReaderWriterFactory.CreateJsonReader(webdata, XmlDictionaryReaderQuotas.Max);

            xr.Read();
            xd.LoadXml(xr.ReadOuterXml());
            xd.Save("\\Server\\ZZZZ\\Downloads\\Data.xml"); 

样本json是：

[
{
        "id" : 21953,
        "mainReqIdentity" : "xxxx",
        "itemName" : "xxxx",
        "kanbanPhase" : "xxxx",
        "kanbanStatus" : "xxxx",
        "backlogItemType" : "xxxx",
        "identityDomain" : "xxxx",
        "fromDatetime" : "2016-08-05 17:52:34",
        "teams" : [],
        "releases" : [{
                "id" : 1229,
                "release_name" : "xxxx",
                "release_connection_type" : "xxxx"
            }
        ],
        "fpReleases" : [],
        "sources" : [{
                "sourceName" : "xxxx",
                "sourceRecordUrl" : "xxxx",
                "sourceRecordIdentity" : "xxxx"
            }
        ],
        "productNumbers" : [],
        "tags" : [],
        "productComponents" : [],
        "ranPlatforms" : [],
        "subReleases" : [],
        "requirementAreaId" : "xxxx",
        "requirementArea" : "xxxx",
        "toBeHandledAtxxxx" : "xxxx"
    }, {
        "id" : 22014,
        "mainReqIdentity" : "xxxx",
        "itemName" : "xxxx",
        "kanbanPhase" : "xxxx",
        "kanbanStatus" : "xxxx",
        "backlogItemType" : "xxxx",
        "identityDomain" : "xxxx",
        "fromDatetime" : "2016-08-05 17:52:34",
        "teams" : [],
        "releases" : [{
                "id" : "xxxx",
                "release_name" : "xxxx",
                "release_connection_type" : "xxxx"
            }
        ],
        "fpReleases" : [],
        "sources" : [{
                "sourceName" : "xxxx",
                "sourceRecordUrl" : "xxxx",
                "sourceRecordIdentity" : "xxxx"
            }
        ],
        "productNumbers" : [],
        "tags" : [],
        "productComponents" : [],
        "ranPlatforms" : [],
        "subReleases" : [],
        "requirementAreaId" : "xxxx",
        "requirementArea" : "xxxx",
        "f0Date" : "2015-10-01",
        "f1Date" : "2015-10-01",
        "f2Date" : "2016-02-01",
        "f4Date" : "2016-03-31",
        "fgDate" : "2016-04-29",
        "toBeHandledAtxxxx" : "xxxx"
    }
    ]

转换后的XML如下所示：

    <root type="array">
    <id type="number">21286</id>
    <mainReqIdentity type="string">xxxxxx</mainReqIdentity>
    <itemName type="string">xxxxxx</itemName>
    <kanbanPhase type="string">xxxxxx</kanbanPhase>
    <kanbanStatus type="string">xxxxxx</kanbanStatus>
    <kanbanNote type="string">xxxxxx</kanbanNote>
    <backlogItemType type="string">xxxxxx</backlogItemType>
    <identityDomain type="string">xxxxxx</identityDomain>
    <fromDatetime type="string">2016-08-23 17:01:52</fromDatetime>
    <teams type="array">
      <item type="object">
        <team_name type="string">xxxxxx</team_name>
        <preliminary type="boolean">xxxxxx</preliminary>
      </item>
    </teams>
    <releases type="array">
      <item type="object">
        <id type="number">xxxxxx</id>
        <release_name type="string">xxxxxx</release_name>
        <release_connection_type type="string">xxxxxx</release_connection_type>
      </item>
    </releases>
    <fpReleases type="array">
    </fpReleases>
    <sources type="array">
      <item type="object">
        <sourceName type="string">xxxxxx</sourceName>
        <sourceRecordUrl type="string">xxxxxx</sourceRecordUrl>
      </item>
    </sources>
    <productNumbers type="array">
    </productNumbers>
    <tags type="array">
    </tags>
    <productComponents type="array">
    </productComponents>
    <ranPlatforms type="array">
    </ranPlatforms>
    <subReleases type="array">
    </subReleases>
    <requirementAreaId type="number">xxxxxx</requirementAreaId>
    <requirementArea type="string">xxxxxx</requirementArea>
    <itemContact type="string">xxxxxx</itemContact>
    <toBeHandledAtxxx type="string">xxxxxx</toBeHandledAtxxx>
  </item>
    <item type="object">
    <id type="number">xxxxxx</id>
    <mainReqIdentity type="string">xxxxxx</mainReqIdentity>
    <itemName type="string">xxxxxx</itemName>
    <kanbanPhase type="string">xxxxxx</kanbanPhase>
    <kanbanStatus type="string">xxxxxx</kanbanStatus>
    <kanbanNote type="string">xxxxxx</kanbanNote>
    <backlogItemType type="string">xxxxxx</backlogItemType>
    <identityDomain type="string">xxxxxx</identityDomain>
    <fromDatetime type="string">2016-08-23 17:01:52</fromDatetime>
    <teams type="array">
      <item type="object">
        <team_name type="string">xxxxxx</team_name>
        <preliminary type="boolean">xxxxxx</preliminary>
      </item>
    </teams>
    <releases type="array">
      <item type="object">
        <id type="number">xxxxxx</id>
        <release_name type="string">xxxxxx</release_name>
        <release_connection_type type="string">xxxxxx</release_connection_type>
      </item>
    </releases>
    <fpReleases type="array">
    </fpReleases>
    <sources type="array">
      <item type="object">
        <sourceName type="string">xxxxxx</sourceName>
        <sourceRecordUrl type="string">xxxxxx</sourceRecordUrl>
      </item>
    </sources>
    <productNumbers type="array">
    </productNumbers>
    <tags type="array">
    </tags>
    <productComponents type="array">
    </productComponents>
    <ranPlatforms type="array">
    </ranPlatforms>
    <subReleases type="array">
    </subReleases>
    <requirementAreaId type="number">xxxxxx</requirementAreaId>
    <requirementArea type="string">xxxxxx</requirementArea>
    <oaResultReference type="string">xxxxxx</oaResultReference>
    <itemContact type="string">xxxxxx</itemContact>
    <f0Date type="string">2014-10-17</f0Date>
    <f1Date type="string">2015-01-16</f1Date>
    <f2Date type="string">2015-02-13</f2Date>
    <f4Date type="string">2015-06-12</f4Date>
    <faDate type="string">2015-06-12</faDate>
    <fgDate type="string">2015-06-12</fgDate>
    <toBeHandledAtxxx type="string">xxxxxx</toBeHandledAtxxx>
  </item>
 </root>

如果在每个节点之前进行观察，则创建一个项类型。我的问题是如何避免在C#类中创建它们。

Answer 1

JsonReaderWriterFactory使用的XML和JSON之间的对应关系用JSON与XML之间的映射描述。特别是：

• 由于XML没有数组原语的概念，所以JSON数组映射到两个XML级别，其中内部元素的本地名称将是"item“。
• 每个元素都添加了一个属性"type"。如文档中所述，此属性用于在映射的XML中保留JSON类型(字符串、数字、布尔值、对象、数组或null)。

如果此映射不能满足您的需要，则可以在存储XML之前使用一些适当的API (例如XSLT变换或LINQ到XML修改)来自定义生成的XML。

例如，LINQ到XML (取代.Net 3.5中的XML )允许在内存中轻松地修改XML。首先，将JSON加载到XDocument中，如下所示：

XDocument xd;
using (var xr = JsonReaderWriterFactory.CreateJsonReader(webdata, XmlDictionaryReaderQuotas.Max))
{
    xd = XDocument.Load(xr);
}

现在，如果您想从其外部容器元素中“取消”数组项，您可以这样做--除非是根元素。如果XML文档的根元素对应于JSON数组，则不能将其项冒泡出来，因为这样做违反了每个精确一个根元素文档必须具有精确一个根元素的规则。话虽如此，以下几点应能奏效：

foreach (var arrayElement in xd.Root.Descendants().Where(e => (string)e.Attribute("type") == "array").ToList())
{
    // Get all child nodes of the array container node.
    var nodes = arrayElement.Nodes().ToList();
    bool anyChildren = false;
    // Change names of child elements from <item> to the name of the container node, <releases> or whatever.
    foreach (var element in nodes.OfType<XElement>())
    {
        anyChildren = true;
        element.Name = arrayElement.Name;
    }
    if (anyChildren)
    {
        // Remove all its child nodes.
        nodes.Remove();
        // Add formerly child nodes right after the container node.
        arrayElement.AddAfterSelf(nodes);
        // Remove the container node itself.
        arrayElement.Remove();
    }
}

(这段代码可能需要为嵌套的JSON数组进一步定制。)

接下来，如果希望删除"type"属性，可以使用以下代码：

foreach (var element in xd.Descendants().Where(e => e.Attribute("type") != null))
    element.Attributes("type").Remove();

最后，要保存文档，请执行以下操作：

xd.Save("\\Server\\ZZZZ\\Downloads\\Data.xml");

将这两个转换链接在一起的结果是：

<root>
  <item>
    <id>21953</id>
    <mainReqIdentity>xxxx</mainReqIdentity>
    <itemName>xxxx</itemName>
    <kanbanPhase>xxxx</kanbanPhase>
    <kanbanStatus>xxxx</kanbanStatus>
    <backlogItemType>xxxx</backlogItemType>
    <identityDomain>xxxx</identityDomain>
    <fromDatetime>2016-08-05 17:52:34</fromDatetime>
    <teams></teams>
    <releases>
      <id>1229</id>
      <release_name>xxxx</release_name>
      <release_connection_type>xxxx</release_connection_type>
    </releases>
    <fpReleases></fpReleases>
    <sources>
      <sourceName>xxxx</sourceName>
      <sourceRecordUrl>xxxx</sourceRecordUrl>
      <sourceRecordIdentity>xxxx</sourceRecordIdentity>
    </sources>
    <productNumbers></productNumbers>
    <tags></tags>
    <productComponents></productComponents>
    <ranPlatforms></ranPlatforms>
    <subReleases></subReleases>
    <requirementAreaId>xxxx</requirementAreaId>
    <requirementArea>xxxx</requirementArea>
    <toBeHandledAtxxxx>xxxx</toBeHandledAtxxxx>
  </item>
  <item>
    <id>22014</id>
    <mainReqIdentity>xxxx</mainReqIdentity>
    <itemName>xxxx</itemName>
    <kanbanPhase>xxxx</kanbanPhase>
    <kanbanStatus>xxxx</kanbanStatus>
    <backlogItemType>xxxx</backlogItemType>
    <identityDomain>xxxx</identityDomain>
    <fromDatetime>2016-08-05 17:52:34</fromDatetime>
    <teams></teams>
    <releases>
      <id>xxxx</id>
      <release_name>xxxx</release_name>
      <release_connection_type>xxxx</release_connection_type>
    </releases>
    <fpReleases></fpReleases>
    <sources>
      <sourceName>xxxx</sourceName>
      <sourceRecordUrl>xxxx</sourceRecordUrl>
      <sourceRecordIdentity>xxxx</sourceRecordIdentity>
    </sources>
    <productNumbers></productNumbers>
    <tags></tags>
    <productComponents></productComponents>
    <ranPlatforms></ranPlatforms>
    <subReleases></subReleases>
    <requirementAreaId>xxxx</requirementAreaId>
    <requirementArea>xxxx</requirementArea>
    <f0Date>2015-10-01</f0Date>
    <f1Date>2015-10-01</f1Date>
    <f2Date>2016-02-01</f2Date>
    <f4Date>2016-03-31</f4Date>
    <fgDate>2016-04-29</fgDate>
    <toBeHandledAtxxxx>xxxx</toBeHandledAtxxxx>
  </item>
</root>