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TSS001475

• 开发伙伴平台：

S60 3rd Edition, 3rd Edition FP1, 3rd Edition FP2, 5th Edition

• 详细描述

这里提供检测系统环境变化的方法，如系统时间改变，线程死亡或区域改变。

我们使用CEnvironmentChangeNotifier来完成上述需求，这是一个活动对象，主要用回调函数TCallBack来完成事件的通知。

• 解决方案

需要的头文件和链接库

#include <bacntf.h> // Link against bafl.lib
<code>
 
<code cpp>
// NotifyChange is a static member function declared as follows: 
// static TInt NotifyChange( TAny* aObject );  
TCallBack envChangeCallback( NotifyChange, this ); 
iEnvNotifier = CEnvironmentChangeNotifier::NewL( CActive::EPriorityHigh, envChangeCallback );  
// Issues a request for change events. When a change events occurs, the  
// callback function is called. Note that after the first call to this  
// function, the callback function is called immediately. iEnvNotifier->Start();

通过TChanges来获取事件通知

TInt CMyEnvironMentChangeNotifier::NotifyChange( TAny* aObject )   
{
   CMyEnvironMentChangeNotifier* thisPtr = static_cast<CMyEnvironMentChangeNotifier*>( aObject );
    // Retrieve the changes in a bit field
   const TInt changes( thisPtr->iEnvNotifier->Change() );
    if( changes & EChangesLocale )
     {
     // System locale changed
     }
   if( changes & EChangesMidnightCrossover )
     {
     // Midnight crossover
     }
    if( changes & EChangesThreadDeath )
     {
     // Thread death
     }
    if( changes & EChangesPowerStatus )
     {
     // Power status changed
     }
    if( changes & EChangesSystemTime )
     {
     // System time changed
     }
    if( changes & EChangesFreeMemory )
     {
     // Free memory changed
     }
    if( changes & EChangesOutOfMemory )
     {
     // Out of memory
     }
 }