// Delete the specified security element if the current time is past
// the time stored in the destroytime tag.
private static SecurityElement DestroyTree(SecurityElement xmlElement)
{
SecurityElement localXmlElement = xmlElement;
SecurityElement destroyElement =
localXmlElement.SearchForChildByTag("destroytime");
// Verify that a destroytime tag exists.
//<Snippet17>
if (localXmlElement.SearchForChildByTag("destroytime") != null)
//</Snippet17>
{
// Retrieve the destroytime text to get the time
// the tree can be destroyed.
//<Snippet18>
string storedDestroyTime =
localXmlElement.SearchForTextOfTag("destroytime");
//</Snippet18>
DateTime destroyTime = DateTime.Parse(storedDestroyTime);
if (DateTime.Now > destroyTime)
{
localXmlElement = null;
Console.WriteLine("The XML security tree has been deleted.");
}
}
// Verify that xmlElement is of type SecurityElement.
//<Snippet21>
if (xmlElement.GetType().Equals(
typeof(System.Security.SecurityElement)))
//</Snippet21>
{
// Determine whether the localXmlElement object
// differs from xmlElement.
//<Snippet20>
if (xmlElement.Equals(localXmlElement))
//</Snippet20>
{
// Verify that the tags, attributes and children of the
// two security elements are identical.
//<Snippet22>
if (xmlElement.Equal(localXmlElement))
//</Snippet22>
{
// Return the original security element.
return(xmlElement);
}
}
}
// Return the modified security element.
return(localXmlElement);
}
