Can somebody explain this weird behavior of AlarmManeger?

Following is a simple alarm invoking procedure, note the number of trout I want to catch:

    private void setReminder() {
        Intent intent = new Intent(this, AlarmReceiver5.class);
        int trout = 21;
        intent.putExtra("intData", trout);
        intent.putExtra("textData", 
            "Great day for fishing! How many trout you want to get today? ");
        PendingIntent sender = PendingIntent.getBroadcast(this, 0, intent, 0);

        AlarmManager am = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 15 * 1000, sender);
    }

1. When I run it for the first time, the BroadcastReceiver correctly sees that I want to catch 21 trout today.

2. I changed the number to 22 in Eclipse, run it again, the receiver still sees 21! No matter how I try here, including uninstalling the program from Android, the receiver always gets the old number.

3. Now if I rename the receiver class from AlarmReceiver5 to AlarmReceiver6, then it can successfully get a different number. But then the same happened again, i.e., no matter how I change the number, the r开发者_运维问答eceiver always gets the old number until I rename the class.

4. However, if I change the element names in the Bundle (i.e., "intData" and "textData" in the above example), the receiver can't get anything at all! The number becomes 0. Of course I updated the receiver side accordingly.

5. The above is true even if I used ApiDemo's AlarmController and OneShotAlarm classes.

Now if I tweak the code a little more, I canceled the alarm before setting the next alarm, then the receiver doesn't get anything, the number is 0. See the code below:

    private void setReminder() {
        AlarmManager am = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(this, AlarmReceiver5.class);
        // Cancel the alarm
        PendingIntent sender = PendingIntent.getBroadcast(this, 0, intent, 0);
        am.cancel(sender);

        // Then set it again (using a newly created PendingIntent).
        sender = PendingIntent.getBroadcast(this, 0, intent, 0);
        int trout = 21;
        intent.putExtra("intData", trout);
        intent.putExtra("textData", 
        "Great day for fishing! How many trout you want to get today? ");
        sender = PendingIntent.getBroadcast(this, 0, intent, 0);
        am.cancel(sender);
        am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 15 * 1000, sender);
}

Can somebody explain what the hack Android AlarmManager is thinking? Thank you! (I may not be able to see your reply for a few hours, because I'm out fishing after posting this.)

in PendingIntent.getBroadcast(this, 0, intent, 0); set the flag parameter (fourth one) to one of the constants in http://developer.android.com/reference/android/app/PendingIntent.html