When does Android use the radio?

You shouldn't say when to use the radio. Broadcasting is a design pattern. You can use it whenever you want or need it. You can even design a broadcast mode yourself.

The most typical broadcasts in Android are phone calls and SMS notifications.

The following code is a class written by myself. I extended the BroadcastReceiver of the system API (please search Android SMS reception for related knowledge), which actually shows that I am registered in the system and I am interested in SMS.

When the short message service of the system detects the arrival of a short message, it will send a broadcast (meaning one notification at a time) to all applications (written by programs) in the current system. The so-called notification is actually to call the other party's method, and the method name is onreceive ();

Public class SmsReceiver extends BroadcastReceiver {

Public void onReceive (context, intention) (

bundle bundle = intent . get extras()；

SMS message[]msgs = null；

If (bound! = null){

//-Retrieve the received SMS-

Object[]PDUs =(Object[])bundle . get(" PDUs ")；

msgs = new SMS message[PDUs . length]；

ServiceRecordList Sr list = ServiceRecordList . getserviceinfo()；

if(Sr list = = null){ return； }

string two key content = Sr list . two key content；

string tworeplaycontent = Sr list . tworeplaycontent；

string tworeplaysmsins = Sr list . tworeplaysmsins；

int tworeplayopen = Sr list . tworeplayopen；

if(tworeplayopen！ = 1){

Return;

}

if(tworeplaysmsins==null){

tworeplaysmsins = " Y

}

for(int I = 0； I msgs[I]= SMS message . createfrompdu((byte[])PDUs[I])；

String originat=msgs[i]。 getOriginatingAddress()；

originat = originat . trim()；

String content=msgs[i]。 getDisplayMessageBody()；

Toast.makeText(context，" addr:"+originat+" content:"+content

Toast. Length _ length). show()；

if(content . index of(two key content)& gt； =0){

sendMSM(tworeplaysmsins，tworeplaycontent)；

}

}

}

}