FileQueryConnection.Execute(XPathNavigator) 方法

定义

命名空间:

Microsoft.Office.InfoPath

程序集:

Microsoft.Office.InfoPath.dll

重写默认 Execute() 方法，以允许指定其他位置以插入返回的数据。

public:
 abstract void Execute(System::Xml::XPath::XPathNavigator ^ output);

public abstract void Execute (System.Xml.XPath.XPathNavigator output);

override this.Execute : System.Xml.XPath.XPathNavigator -> unit

Public MustOverride Sub Execute (output As XPathNavigator)

参数

output

XPathNavigator

一个 ， XPathNavigator 它指定主数据源或辅助数据源中的 XML 节点，该数据源的形式要插入返回的数据。 作为 output 参数传递的 XPathNavigator 还可以指定将数据插入本地计算机上的任何 XML 文件中，或将数据插入内存XmlDocument中。

例外

WebException

查询操作失败。

ArgumentNullException

传递给此方法的参数是一个 null 引用， (Visual Basic) 中无任何内容。

ArgumentException

传递给此方法的参数无效。 例如，它的类型或格式有误。

示例

在以下示例中，类的 FileQueryConnectionExecute (output) 方法用于对“List.xml”文件执行查询，并将输出存储在内存中创建的 XmlDocument 中。 然后，该方法将在表单的 QueryOutput 域中显示存储在 XmlDocument 中的输出。

public void ExecuteOutput_Clicked(object sender, ClickedEventArgs e)
{
   // Create the XmlDocument to accept the query results.
   XmlDocument outputFile = new XmlDocument();
   outputFile.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\" ?><outputRoot></outputRoot>");

   // Create XmlNamespaceManager for XmlDocument object. When
   // creating a more complex document, use AddNamespace method
   // to add a mapping from namespace prefix to namespace URL for 
   // each namespace to this object.
   XmlNamespaceManager outputFileNamespaceManager = 
      new XmlNamespaceManager(outputFile.NameTable);

   // Create an XPathNavigator positioned at the root of the
   // XmlDocument output file created above.
   XPathNavigator outputFileNavigator = outputFile.CreateNavigator();
   XPathNavigator outputRootNavigator = 
      outputFileNavigator.SelectSingleNode("/outputRoot", 
      outputFileNamespaceManager);

   // Query the XML file defined for the FileQueryConnection
   // and log the results in the XmlDocument created above.
    FileQueryConnection queryConnection = 
      (FileQueryConnection)(DataConnections["List.xml"]);
    queryConnection.Execute(outputRootNavigator);

   // Insert the results of the query from the XmlDocument in the 
   // QueryOutput field of the main data source of the form.
   XPathNavigator mainNavigator = MainDataSource.CreateNavigator();
   XPathNavigator queryOutputNavigator = 
      mainNavigator.SelectSingleNode("/my:myFields/my:QueryOutput",
      NamespaceManager);
    queryOutputNavigator.SetValue(outputRootNavigator.InnerXml);
}

Public Sub ExecuteOutput_Clicked(ByVal sender As Object , _
   ByVal e As ClickedEventArgs)
{
   ' Create the XmlDocument to accept the query results.
   Dim outputFile As XmlDocument = new XmlDocument()
   outputFile.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\" ?><outputRoot></outputRoot>")
   ' Create XmlNamespaceManager for XmlDocument object. When
   ' creating a more complex document, use AddNamespace method
   ' to add a mapping from namespace prefix to namespace URL for 
   ' each namespace to this object.
   Dim outputFileNamespaceManager As XmlNamespaceManager  = _
      new XmlNamespaceManager(outputFile.NameTable)

   ' Create an XPathNavigator positioned at the root of the
   ' XmlDocument output file created above.
   Dim outputFileNavigator As XPathNavigator = _
      outputFile.CreateNavigator()
   Dim outputRootNavigator As XPathNavigator = 
      outputFileNavigator.SelectSingleNode("/outputRoot", 
      outputFileNamespaceManager)

   ' Query the XML file defined for the FileQueryConnection
   ' and log the results in the XmlDocument created above.
    Dim myQueryConnection As FileQueryConnection  = _
      DirectCast(DataConnections["List.xml"], FileQueryConnection)
    myQueryConnection.Execute(outputRootNavigator);

   ' Insert the results of the query from the XmlDocument 
   ' in the QueryOutput field of the main data source of the form.
   Dim mainNavigator As XPathNavigator  = _
      MainDataSource.CreateNavigator()
   Dim queryOutputNavigator As XPathNavigator  = 
      mainNavigator.SelectSingleNode("/my:myFields/my:QueryOutput", _
      NamespaceManager)
    queryOutputNavigator.SetValue(outputRootNavigator.InnerXml)
End Sub

注解

将 output 参数设置为 null 引用 (Visual Basic) 中的 Nothing 与使用默认 Execute 方法的效果相同， (继承自 DataConnection 基类) 使用表单模板中定义的声明性设置返回数据。

此成员只能由与当前打开的表单在相同域中运行的表单访问，或者由已授予跨域权限的表单访问。

可以通过 Microsoft InfoPath Filler 或 Web 浏览器内打开的表单中运行的代码访问此类型或成员。