NavigationContext Class
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Represents the state of a navigation operation.
Inheritance Hierarchy
System.Object
System.Windows.Navigation.NavigationContext
Namespace: System.Windows.Navigation
Assembly: System.Windows.Controls.Navigation (in System.Windows.Controls.Navigation.dll)
Syntax
'Declaration
Public NotInheritable Class NavigationContext
public sealed class NavigationContext
The NavigationContext type exposes the following members.
.gif "Public property")
Methods
| Name | Description | |
|---|---|---|
.gif "Public method") |
Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
.gif "Protected method") |
Finalize | Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.) |
|
GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
|
GetType | Gets the Type of the current instance. (Inherited from Object.) |
|
MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
|
ToString | Returns a string that represents the current object. (Inherited from Object.) |
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Remarks
You use the NavigationContext class to retrieve the query string values for a navigation request. With the query string values, you can generate the desired state of a page for a navigation request. For example, you can store in the query string the identifier of the record you wish to display on a page.
To access an instance of the NavigationContext class, you use the NavigationContext property of the Page class.
Examples
The following example shows how to override the OnNavigatedTo in a Silverlight page and obtain a query string value from the NavigationContext object. The query string value is used to determine which product is retrieved from a data service and displayed in the page.
Protected Overrides Sub OnNavigatedTo(ByVal e As System.Windows.Navigation.NavigationEventArgs)
Dim productID As String
Dim svcContext As DataServiceContext
svcContext = New DataServiceContext(New Uri("AdventureWorks.svc", _
UriKind.Relative))
If (Me.NavigationContext.QueryString.ContainsKey("ProductId")) Then
productID = Me.NavigationContext.QueryString("ProductId")
Else
productID = App.Current.Resources("FeaturedProductID").ToString()
End If
svcContext.BeginExecute(Of Product)(New Uri("Product(" + productID + ")", _
UriKind.Relative), AddressOf loadProductCallback, svcContext)
End Sub
Private Sub loadProductCallback(ByVal asyncResult As IAsyncResult)
Dim context As DataServiceContext
context = asyncResult.AsyncState
ListBox1.DataContext = context.EndExecute(Of Product)(asyncResult)
End Sub
protected override void OnNavigatedTo(NavigationEventArgs e)
{
string productID;
DataServiceContext svcContext =
new DataServiceContext(new Uri("AdventureWorks.svc", UriKind.Relative));
if (this.NavigationContext.QueryString.ContainsKey("ProductId"))
{
productID = this.NavigationContext.QueryString["ProductId"];
}
else
{
productID = App.Current.Resources["FeaturedProductID"].ToString();
}
svcContext.BeginExecute<Product>(new Uri("Product(" + productID + ")",
UriKind.Relative), loadProductCallback, svcContext);
}
private void loadProductCallback(IAsyncResult asyncResult)
{
DataServiceContext context = asyncResult.AsyncState as DataServiceContext;
ListBox1.DataContext = context.EndExecute<Product>(asyncResult);
}
Version Information
Silverlight
Supported in: 5, 4, 3
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also