SiteMapProvider.RootProvider Property

Definition

Namespace:

System.Web

Assembly:

System.Web.dll

Gets the root SiteMapProvider object in the current provider hierarchy.

public:
 virtual property System::Web::SiteMapProvider ^ RootProvider { System::Web::SiteMapProvider ^ get(); };

public virtual System.Web.SiteMapProvider RootProvider { get; }

member this.RootProvider : System.Web.SiteMapProvider

Public Overridable ReadOnly Property RootProvider As SiteMapProvider

Property Value

SiteMapProvider

An SiteMapProvider that is the top-level site map provider in the provider hierarchy that the current provider belongs to.

Exceptions

ProviderException

There is a circular reference to the current site map provider.

Examples

The following code example demonstrates how to implement the RootProvider property in a class that implements the abstract SiteMapProvider class. The SimpleTextSiteMapProvider uses simple logic to determine whether the current provider is part of a provider hierarchy. If the provider is part of a hierarchy, it uses the RootProvider property for the parent provider as its own. If the provider is not part of a hierarchy, the provider is its own root provider.

This code example is part of a larger example provided for the SiteMapProvider class.

// Implement the ParentProvider property.
public override SiteMapProvider ParentProvider
{
  get
  {
    return parentSiteMapProvider;
  }
  set
  {
    parentSiteMapProvider = value;
  }
}

// Implement the RootProvider property.
public override SiteMapProvider RootProvider
{
  get
  {
    // If the current instance belongs to a provider hierarchy, it
    // cannot be the RootProvider. Rely on the ParentProvider.
    if (this.ParentProvider != null)
    {
      return ParentProvider.RootProvider;
    }
    // If the current instance does not have a ParentProvider, it is
    // not a child in a hierarchy, and can be the RootProvider.
    else
    {
      return this;
    }
  }
}

' Implement the ParentProvider property.
Public Overrides Property ParentProvider() As SiteMapProvider
  Get
    Return parentSiteMapProvider
  End Get
  Set(ByVal value As SiteMapProvider)
    parentSiteMapProvider = Value
  End Set
End Property

' Implement the RootProvider property.
Public Overrides ReadOnly Property RootProvider() As SiteMapProvider
  Get
    ' If the current instance belongs to a provider hierarchy, it
    ' cannot be the RootProvider. Rely on the ParentProvider.
    If Not (Me.ParentProvider Is Nothing) Then
      Return ParentProvider.RootProvider
      ' If the current instance does not have a ParentProvider, it is
      ' not a child in a hierarchy, and can be the RootProvider.
    Else
      Return Me
    End If
  End Get
End Property

Remarks

All classes that implement the SiteMapProvider class can support the concept of a site map provider hierarchy. Any hierarchical relationships between providers are maintained outside the scope of a SiteMapProviderCollection collection by the providers themselves. For an example of a functional provider hierarchy, see XmlSiteMapProvider.

See also

• ParentProvider