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<concept id="GUID-868C1A38-3CD0-4082-8106-DC3EE1F815D8" xml:lang="en"><title>System

events</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>System events are enumerated in <xref href="GUID-95954F7F-E214-309C-AF32-3A9BD77BDC31.dita"><apiname>TApaSystemEvent</apiname></xref>,

which is defined in the <parmname>apgtask.h</parmname>. You must override <xref href="GUID-92361912-7768-3D2C-835E-BD3EF1366D6D.dita#GUID-92361912-7768-3D2C-835E-BD3EF1366D6D/GUID-71190B7E-A39E-3F20-A0D6-A519776A1480"><apiname>CCoeAppUI::HandleSystemEventL()</apiname></xref> to

handle these events, which should be done in the UI controller. The default

implementation is empty. The possible events are as follows:</p>

<codeblock id="GUID-F0606F71-729A-4D6B-AAC6-876A526DDFAC" xml:space="preserve">enum TApaSystemEvent

    {

    EApaSystemEventShutdown = 1,

    EApaSystemEventBackupStarting,

    EApaSystemEventBackupComplete,

    EApaSystemEventBroughtToForeground

    };

</codeblock>

<p>The following is a code example of system event handling:</p>

<codeblock id="GUID-86877508-AD28-4576-B9D5-55565B0F4A4A" xml:space="preserve">void CExampleAppUI::HandleSystemEvent( const TWsEvent&amp; aEvent )

    {

    switch( *( TApaSystemEvent* )( aEvent.EventData() ) )

        {

        case EApaSystemEventBackupStarting:

            {

            // Handle backup starting

            //...

            break;

            }

        case EApaSystemEventBackupComplete:

            {

            // Handle backup complete

            //...

            break;

            }

        case EApaSystemEventShutdown:

            {

            // Handle shutdown

            //...

            break;

            }

        default:

            {

            break;

            }

        }

        // Call the base class implementation

        CAknAppUi::HandleSystemEvent( aEvent );

    }

</codeblock>