แก้ไข

แชร์ผ่าน


CacheDependency.HasChanged Property

Definition

Gets a value indicating whether the CacheDependency object has changed.

public:
 property bool HasChanged { bool get(); };
public bool HasChanged { get; }
member this.HasChanged : bool
Public ReadOnly Property HasChanged As Boolean

Property Value

true if the CacheDependency object has changed; otherwise, false. The default is false.

Examples

The following code example demonstrates using the HasChanged property to determine whether 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.

// 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.");
' 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 

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 and removed from the cache. You can use this property to determine whether a CacheDependency has changed, and recreate the item in the Cache if that has occurred.

Applies to

See also