CacheDependency.HasChanged Property
Gets a value indicating whether the CacheDependency object has changed.
[Visual Basic] Public ReadOnly Property HasChanged As Boolean [C#] public bool HasChanged {get;} [C++] public: __property bool get_HasChanged(); [JScript] public function get HasChanged() : Boolean;
Property Value
true if the CacheDependency object has changed; otherwise, false. The default is false.
Remarks
You can add an item to an ASP.NET application's Cache with a CacheDependency. When the CacheDependency changes, the item added to the Cache is invalidated. You can use this property to determine if a CacheDependency has changed, and recreate an item in the Cache if that has occurred.
Example
[Visual Basic, C#] The following example demonstrates using the HasChanged property to determine if a CacheDependency changed since the previous request for an item in the Cache. The dt value passed in the start parameter is set to DateTime.Now.
[Visual Basic] ' Insert the cache item. Dim dep As New CacheDependency(fileName, dt) myCache.Insert("key", "value", dep) ' Check whether CacheDependency.HasChanged is true. If dep.HasChanged Then Response.Write("<p>The dependency has changed.") Else Response.Write("<p>The dependency has not changed.") End If [C#] // Insert the cache item. CacheDependency dep = new CacheDependency(fileName, dt); cache.Insert("key", "value", dep); // Check whether CacheDependency.HasChanged is true. if (dep.HasChanged) Response.Write("<p>The dependency has changed."); else Response.Write("<p>The dependency has not changed.");
[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
See Also
CacheDependency Class | CacheDependency Members | System.Web.Caching Namespace