<receiver android:name=".receiver.BootUpReceiver">   
  <intent-filter>   
    <action android:name="android.intent.action.BOOT_COMPLETED" />   
  </intent-filter>   
</receiver>  

public class BootUpReceiver extends BroadcastReceiver{   
    private SharedPreferences sharedPreferences;// 配置檔案   
    private Editor editor;// 更改配置檔案的類例項    
    @Override   
    public void onReceive(Context context, Intent intent) {   
        if(intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)){   
               
            sharedPreferences = context.getSharedPreferences("這是儲存檔案的名字",   
                    Context.MODE_PRIVATE);   
            editor = sharedPreferences.edit();   
               
            editor.putLong("儲存時間的key", new Date().getTime());   
  
            editor.commit();//別忘了提交哦   
        }   
           
    }   
}  
 

/**
     * Description : 獲取開機的時間
     *
     *@return String 秒數
     *
     */  
    public static long getUpTime(Activity context) {   
        SharedPreferences sharedPreferences=context.getSharedPreferences("這是儲存檔案的名字",       Context.MODE_PRIVATE);   
           
        long seconds= sharedPreferences.getLong("儲存時間的key", new Date().getTime());   
        return seconds;   
    }