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UserControl.IsPostBack Property

Gets a value indicating whether the user control is being loaded in response to a client postback, or if it is being loaded and accessed for the first time.

Namespace:  System.Web.UI
Assembly:  System.Web (in System.Web.dll)

public bool IsPostBack { get; }

Property Value

Type: System.Boolean
true if the user control is being loaded in response to a client postback; otherwise, false.

The following example adds two key value pairs to the application state associated with a user control if the user control's IsPostBack property returns false. When this condition is met, the code uses the Add method, through the user control's Application property, to add the keys and their values.

if (!myControl.IsPostBack)
  // Add new objects to the HttpApplicationState.
  // These will be maintained as long as the application is active.
  myControl.Application.Add("Date",new DateTime(2001,6,21));
  // Add an object to the cache with expirations 
  // set to 0.1 minute.
  myControl.Cache.Insert("MyData1", "somevalue", null, DateTime.Now.AddMinutes(0.1), Cache.NoSlidingExpiration);

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.