(kotlin初学者)广播接收器收不到正确的的context

[Echo-YeZi]

在MainActivity中动态注册广播然后发布广播
然而广播接收器onReceive收到的context是android.app.Application,并不是期望的com.example.broadcastdemo2.MainActivity
因此 dialogBuilder.show()无法使用
代码片段如下

//MainActivity

class MainActivity : BaseActivity() {

    private var localReceiver: MyBcReceiver? = null
    private var localBroadcastManager: LocalBroadcastManager? = null
    private var intentFilter: IntentFilter? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)          //初始化界面
        localBroadcastManager = LocalBroadcastManager.getInstance(this@MainActivity) //获取broadcast管理器
        Log.e("main", "this:" + this)
        Log.e("main", "MainContext :" + this@MainActivity)
        //初始化广播接收者，设置过滤器
        localReceiver = MyBcReceiver()      //获取广播接收器
        intentFilter = IntentFilter()       //获取过滤器
        intentFilter!!.addAction("com.jay.mybcreceiver.LOGIN_OTHER")    //添加过滤规则
        localBroadcastManager!!.registerReceiver(localReceiver!!, intentFilter!!)

        val btn_send = findViewById<View>(R.id.btn_send) as Button
        btn_send.setOnClickListener {
            val intent = Intent("com.jay.mybcreceiver.LOGIN_OTHER")
            //localBroadcastManager!!.sendBroadcast(intent)
            Handler().postDelayed(Runnable { localBroadcastManager!!.sendBroadcast(intent)}, 100L)
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        localBroadcastManager!!.unregisterReceiver(localReceiver!!)
    }
}

//MyBcReceiver
class MyBcReceiver : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent?) {
        Log.e("dynamic receiver", "Context :" + context)
        Log.e("dynamic receiver", "Intent  := " + intent)
        Log.e("dynamic receiver", "this    := " + this@MyBcReceiver)
        val dialogBuilder :AlertDialog.Builder = AlertDialog.Builder(context)
        dialogBuilder.setTitle("警告：")
        dialogBuilder.setMessage("您的账号在别处登录，请重新登陆~")
        dialogBuilder.setCancelable(false)
        dialogBuilder.show()
    }
}

运行结果如下

抛出错误

[Echo-YeZi]

但是在onReceive中使用

Toast.makeText(context, "重复登录", Toast.LENGTH_SHORT).show()

这个是可以正常执行的.... 难道说问题不在context???

[王能]

问题当然在context了，Application和service只能弹全局的对话框。

    public static Activity mTopActivity;
        registerActivityLifecycleCallbacks(new Application.ActivityLifecycleCallbacks() {
            @Override
            public void onActivityCreated(Activity activity, Bundle bundle) {
                mActivityDestroyCount++;
                mIsAcitivytDestroy = false;
            }

            @Override
            public void onActivityStarted(Activity activity) {
                mActivityStopCount++;
                mIsActivityInBackground = false;
            }

            @Override
            public void onActivityResumed(Activity activity) {
                mTopActivity = activity;
            }

            @Override
            public void onActivityStopped(Activity activity) {
                mActivityStopCount--;
                if (mActivityStopCount == 0) {
                    mIsActivityInBackground = true;
//                    Utils.Toast("切到后台");
                }
            }

            @Override
            public void onActivityDestroyed(Activity activity) {
                mActivityDestroyCount--;
                if (mActivityDestroyCount == 0) {
                    mTopActivity = null;
                    mIsAcitivytDestroy = true;
//                    Utils.Toast("所有activity已销毁");
                }
            }

            @Override
            public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
            }

            @Override
            public void onActivityPaused(Activity activity) {
            }
        });

在Application里加上这道逻辑就行了，弹窗直接用topActivity即可 还有，你的receive貌似没啥用

[王能]

这是java代码，自行转成科特林的吧

[Echo-YeZi]

引用 3 楼 王能 的回复:

这是java代码，自行转成科特林的吧

不是 kotlin的 我直接从kotlin入手的,,,

[Echo-YeZi]

引用 3 楼 王能 的回复:

这是java代码，自行转成科特林的吧

我试试自己转成kotlin 谢谢大佬