Control.OnUnload Method

Raises the Unload event.

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

'Declaration
Protected Friend Overridable Sub OnUnload ( _
	e As EventArgs _
)
'Usage
Dim e As EventArgs

Me.OnUnload(e)
protected void OnUnload (
	EventArgs e
)
protected internal function OnUnload (
	e : EventArgs
)
Not applicable.

Parameters

e

An EventArgs object that contains event data.

Server controls should perform any final cleanup, such as closing files, closing database connections, and discarding objects, during this stage of the server control lifecycle.

The following example creates a text stream object, myFile, and uses it to print messages to a text file when defined Page and control lifecycle events occur during request processing. During the OnUnload method call, the string "Custom control was unloaded" is written to the file and the text stream object is closed.

   ' Create a StreamWriter to write data to a text file.
    Dim myFile As TextWriter = File.CreateText("c:\NewTextFile.txt")

   Sub Page_Load(sender As Object, e As EventArgs)
' Write status to file.
myFile.WriteLine("Page has loaded.")
   End Sub

   Sub CustomControl_OnLoad(sender As Object, e As EventArgs)
myFile.WriteLine("Custom control has loaded.")
   End Sub

   Sub CustomControl_OnUnload(sender As Object, e As EventArgs)
' Server controls final cleanup such as;
' closing files etc.goes here         
myFile.WriteLine("Custom control was unloaded.")
' Close the stream object.
myFile.Close()
   End Sub

// Create a StreamWriter to write data to a text file.
TextWriter myFile = File.CreateText("c:\\NewTextFile.txt");

void Page_Load(Object sender,EventArgs e)
{
    // Write status to file.
    myFile.WriteLine("Page has loaded.");
} //Page_Load

void CustomControl_OnLoad(Object sender,EventArgs e)
{
    myFile.WriteLine("Custom control has loaded.");
} //CustomControl_OnLoad

void CustomControl_OnUnload(Object sender,EventArgs e)
{
    // Server controls final cleanup such as; 
    // closing files goes here         
    myFile.WriteLine("Custom control was unloaded.");
    // Close the stream object.
    myFile.Close();
} //CustomControl_OnUnload

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

Community Additions

ADD
Show: