Categories: Symbian C++ | Code Examples | S60 3rd Edition

This page was last modified 10:22, 20 May 2008.

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Overview

The following example shows how to send custom messages from CAknView to another CAknView while activating the view.

MMP file

The following capabilities and libraries are required:

CAPABILITY        NONE
LIBRARY           avkon.lib

Header, sending custom message

#include <aknview.h>
const TUid KView1Id = {1};
const TUid KView2Id = {2};
const TUid KCustomMessageUid= {2};    // Your custom message uid
 
public:
    void CFirstView::HandleCommandL(TInt aCommand);

Source, sending custom message

void CFirstView::HandleCommandL(TInt aCommand)
    {   
    switch ( aCommand )
        {
        case EOpenSecondView:
            {
            // Switch to view 2 and send a message Uid and a message
 
            // Construct a message to send
            TBuf8<255> customMessage;
            customMessage.Copy(_L8("Message from firsto view"));
            
            // Activate the second view and give the message as a parameter
            AppUi()->ActivateLocalViewL(KView2Id, KCustomMessageUid, customMessage);
            break;
            }
        }
        default:
        {
        break;
        }

Header, receiving custom message

#include <aknview.h>
#include "CFirstView.h"
 
public:
    void CSecondView::DoActivateL(const TVwsViewId& aPrevViewId,
    TUid aCustomMessageId, const TDesC8& aCustomMessage);
 
private:
    HBufC8* iReceivedMessage;

Source, receiving custom message

void CSecondView::DoActivateL(const TVwsViewId& aPrevViewId,
TUid aCustomMessageId, const TDesC8& aCustomMessage)
    {
    // Create Container
    if (!iContainer)
        {
        iContainer = new (ELeave) CMyViewContainer2;
        iContainer->ConstructL( ClientRect() );
        AppUi()->AddToStackL( *this, iContainer );
        }
 
 
    // 1. Check aCustomMessageId to handle aCustomMessage
    // 2. You could check aPrevViewId if you were curious to know
    //    from where this view was called from.
    if (aCustomMessageId==KCustomMessageUid)
        {
        // TODO: Do something with aCustomMessage
        iReceivedMessage = aCustomMessage.AllocL();
        }
   }

Postconditions

When the second view is activated it can receive a custom message from the previous view.