Question

我是Android新手，尝试使用EventBus将消息从Fragment发送到其容器Activity。但是，我收到了错误：

D/EventBus: No subscribers registered for event class com.app.todo.controllers.task.TaskListFragment$TaskCreateSelectEvent

以下是与EventBus相关的Activity类中的代码：

public class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
    }

    @Subscribe(threadMode = ThreadMode.MAIN)
    fun onTaskCreateSelectEvent(event: TaskListFragment.TaskCreateSelectEvent) {
        Log.d("TAG", "On Main Activity")
    }

    fun addFragment(fragment: Fragment) {
        val transaction = supportFragmentManager.beginTransaction()
        transaction.setCustomAnimations(R.anim.enter, R.anim.exit, R.anim.pop_enter, R.anim.pop_exit)
        transaction.add(R.id.task_fragment_container, fragment)
        transaction.addToBackStack(fragment.javaClass.simpleName)
        transaction.commit()
    }

    public override fun onStart() {
        super.onStart()
        EventBus.getDefault().register(this)
    }

    public override fun onStop() {
        super.onStop()
        EventBus.getDefault().unregister(this)
    }

}

以下是Fragment类

public class TaskListFragment : Fragment() {
    private var fab: FloatingActionButton? = null

    public class TaskCreateSelectEvent {
        var fab: FloatingActionButton? = null
    }

    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        var view = inflater!!.inflate(R.layout.task_list_fragment, container, false)
        fab = view.findViewById<FloatingActionButton>(R.id.fab)
        fab!!.setOnClickListener {
            val selectEvent = TaskCreateSelectEvent()
            EventBus.getDefault().post(selectEvent)
        }
        return view
    }
}

这是build.gradle文件中添加库的方式。

apply plugin: 'kotlin-kapt'

dependencies {
    compile 'org.greenrobot:eventbus:3.0.0'
    kapt 'org.greenrobot:eventbus-annotation-processor:3.0.1' }

kapt {
    arguments {
        arg('eventBusIndex', 'com.app.todo.controllers.MyEventBusIndex')
    } 
}

知道我做错了吗？

Answer 1

我是Android新手......

那么你最好熟悉匕首和rx。事件总线在Android上是一个坏事，并且经常使事情变得更加复杂。

https://www.google.de/search?q=android+rxjava+instead+of+eventbus

Answer 2

尝试将您订阅的方法名称更改为：

onMessageEvent(event: TaskListFragment.TaskCreateSelectEvent)

但正如@Lord Flash建议的那样 - 使用rxjava而不是eventbus。 Tkae看看PublishSubject/PublishProcessor（rx 2.0）类

与Kotlin无法正常工作的EventBus

2 个答案: