（一）这个是BroadcastReceiver类中发送广播开始传值
Intent myIntent = new Intent(“android.intent.action.MAIN”);
myIntent.putExtra(“data”,alert1);
context.sendBroadcast(myIntent);
（二）activity接收值
private BroadcastReceiver mReceiver;

mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {

                   String data = intent.getStringExtra("data")   ;
                   Log.e("接收到的数据是",data);

        }
    };
    IntentFilter intentFilter = new IntentFilter("android.intent.action.MAIN");
    registerReceiver(mReceiver, intentFilter);