Kotlin学习笔记——BroadCast Kotlin学习笔记——BroadCast

#define 小毛驴 xml

收发广播使用场景：Fragment想要向外传递信息

在Fragment中发送广播

class BlankFragment : Fragment() { var ctx:Context? = null var mPosition:Int = 0 var mInageId:Int = 0 var mDesc:String = "" var title:String = ""val colorNames = listOf("红色","黄色","绿色","青色","蓝色") val colors = intArrayOf(Color.RED, Color.YELLOW, Color.GREEN, Color.CYAN, Color.BLUE) var mSeq:Int = 0 override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { ctx = activity if (arguments != null) { mPosition = arguments!!.getInt("position", 0) mInageId = arguments!!.getInt("image_id", 0) mDesc = arguments!!.getString("desc") title = arguments!!.getString("title") } val view = inflater.inflate(R.layout.show_info, container, false)view.findViewById(R.id.imageView).setImageResource(mInageId) view.findViewById(R.id.textView).text = mDesc view.findViewById

在要接收广播的页面注册receiver

class MainActivity : FragmentActivity(){ private var BGChangeRecever:myBgChangeRecever? = null override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) var vp:ViewPager = findViewById(R.id.vp) var title: PagerTabStrip = findViewById(R.id.title)val pics = arrayOf(R.mipmap.basic, R.mipmap.close, R.mipmap.debug, R.mipmap.edit) val list:MutableList = mutableListOf() for (i in pics.indices) { list.add(itemInfo((i+1).toString(), pics[i], ((i+1)*(i+1)).toString())) } vp.adapter = infoPagerAdapter(supportFragmentManager, list) vp.currentItem = 0 }public override fun onStart() { super.onStart() BGChangeRecever = myBgChangeRecever()val filiter = IntentFilter(BlankFragment.EVENT)//广播过滤器，过滤掉参数以外的广播 registerReceiver(BGChangeRecever,filiter)//开始时注册接收器}public override fun onStop() { unregisterReceiver(BGChangeRecever)//结束前注销接收器 super.onStop() }private inner class myBgChangeRecever : BroadcastReceiver() {//广播接收器 override fun onReceive(context: Context?, intent: Intent?) {//接收广播后执行的操作 if (intent != null) { val color = intent.getIntExtra("color", Color.GREEN) textView2.setTextColor(color) } }} }

接收系统广播静态注册 【Kotlin学习笔记——BroadCast】没学会
动态注册

class MainActivity : AppCompatActivity() { var receiver:broadCastRecever = broadCastRecever() override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) }override fun onDestroy() { super.onDestroy() receiver.unRegiste() }override fun onStart() { super.onStart() receiver.registe(this) }inner class broadCastRecever : BroadcastReceiver() { private var isRegisted = false var allBroadCast = arrayOf(Intent.ACTION_TIME_TICK, Intent.ACTION_SCREEN_ON, Intent.ACTION_SCREEN_OFF) var registTo:Context? = null override fun onReceive(context: Context?, intent: Intent?) { text.append("收到：${(intent?.action?:"empty")}\n") } fun registe(context: Context) { if (!isRegisted) { var filter:IntentFilter = IntentFilter() for (item in allBroadCast) { filter.addAction(item) } context.registerReceiver(this@broadCastRecever, filter) isRegisted = true registTo = context } } fun unRegiste() { if (isRegisted) { registTo?.unregisterReceiver(this@broadCastRecever) isRegisted = false } } } }