View.GetContextNodes Method (XPathNavigator, String)

Artículo
07/24/2014

Gets a reference to an XPathNodeIterator for iterating over the returned XML nodes in the current selection within the control bound to the specified control.

Namespace: Microsoft.Office.InfoPath
Assembly: Microsoft.Office.InfoPath (in Microsoft.Office.InfoPath.dll)

Syntax

'Declaration
Public MustOverride Function GetContextNodes ( _
    xmlNode As XPathNavigator, _
    controlId As String _
) As XPathNodeIterator
'Usage
Dim instance As View
Dim xmlNode As XPathNavigator
Dim controlId As String
Dim returnValue As XPathNodeIterator

returnValue = instance.GetContextNodes(xmlNode, _
    controlId)

public abstract XPathNodeIterator GetContextNodes(
    XPathNavigator xmlNode,
    string controlId
)

Parameters

xmlNode
Type: System.Xml.XPath.XPathNavigator

An object that specifies the node to get.

controlId
Type: System.String

The ViewContext identifier of the control that contains the currently selected XML nodes to return.

Return Value

Type: System.Xml.XPath.XPathNodeIterator
An XPathNodeIterator that is populated with the nodes in the current selection.

Exceptions

Exception	Condition
InvalidOperationException	The GetContextNodes method was called from an event handler for the Loading event.
ArgumentNullException	The parameters passed to this method are a null reference (Nothing in Visual Basic).
ArgumentException	The parameters passed to this method are not valid. For example, they are of the wrong type or format.

Remarks

You can determine the ViewContext identifier for a control or group by opening the form template in Design mode, displaying the control's Properties dialog box, and then clicking the Advanced tab.

When the ViewContext identifier is specified, all of the XML nodes that have been specified to be selected must be within that context.

The XML nodes returned by the GetContextNodes method consists of a sequence of nodes that are mapped from the view, corresponding to the current XSL Transformation (XSLT) node, starting at the current selection and walking up through the view ancestors to the BODY tag.

Note

The GetContextNodes method will not return nodes based on the current selection if used in the event handler for the Clicked event of a button in the view, because the focus is lost from the control that is intended to be in context. To avoid this behavior, use GetContextNodes from a custom task pane, menu, or toolbar.

This member can be accessed only by forms running in the same domain as the currently open form, or by forms that have been granted cross-domain permissions.

This type or member can be accessed only from code running in forms opened in Microsoft InfoPath Filler.

Examples

In the following example, the SelectNodes(XPathNavigator, XPathNavigator, String) method is used to select the nodes in the first row of a Repeating Table control bound to group2. The GetContextNodes method is then used to return a collection of context nodes based on the current selection and the specified node. Finally, the code loops through the collection of context nodes and displays the name, inner XML, and value of each node.

// Create XPathNavigator and specify XPath for nodes.
XPathNavigator repeatingTableRow1 = 
   MainDataSource.CreateNavigator().SelectSingleNode(
   "/my:myFields/my:group1/my:group2[1]", NamespaceManager);

// Select nodes in specified XPathNavigator.
CurrentView.SelectNodes(repeatingTableRow1,repeatingTableRow1,"CTRL5");

// Get context nodes in selection.
XPathNodeIterator contextNodes = 
   CurrentView.GetContextNodes(repeatingTableRow1,"CTRL5");

// Loop through collection and display information.
foreach (XPathNavigator contextNode in contextNodes)
{
   MessageBox.Show(contextNode.Name);
   MessageBox.Show(contextNode.InnerXml);
   MessageBox.Show(contextNode.Value);
}

' Create XPathNavigator and specify XPath for nodes.
Dim repeatingTableRow1 As XPathNavigator  = _
   CreateNavigator().SelectSingleNode( _
   "/my:myFields/my:group1/my:group2[1]", NamespaceManager)

' Select nodes in specified XPathNavigator.
CurrentView.SelectNodes(repeatingTableRow1,repeatingTableRow1,"CTRL5")

' Get context nodes in selection.
Dim contextNodes As XPathNodeIterator = _
   CurrentView.GetContextNodes(repeatingTableRow1)

' Loop through collection and display information.
Dim contextNode As XPathNavigator
For Each contextNode In contextNodes
   MessageBox.Show(contextNode.Name)
   MessageBox.Show(contextNode.InnerXml)
   MessageBox.Show(contextNode.Value)
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