如何在活动中监听片段变化？

Question

private fun changeBottomBar(corpo: Boolean = false) {
    if (corpo) {
        binding.bottomAppBar.navigationIcon = ContextCompat.getDrawable(
            this,
            R.drawable.ic_baseline_menu_24
        )
        binding.bottomAppBar.menu.findItem(R.id.filter).isVisible = false
        binding.bottomSheetTestata.titleBottomSheet.text = "Modifica Documento"
        bottomSheetTestataBehavior.state = BottomSheetBehavior.STATE_COLLAPSED
        binding.bottomAppBar.menu.findItem(R.id.testata).isVisible = tipo != "Etichette"
    }else {
        binding.bottomAppBar.navigationIcon = null
        binding.bottomAppBar.menu?.findItem(R.id.testata)?.isVisible = false
        binding.bottomAppBar.menu?.findItem(R.id.filter)?.isVisible = true
        binding.bottomSheetTestata.titleBottomSheet.text = "Nuovo Documento"
        clearTestata()
        bottomSheetBehavior.state = BottomSheetBehavior.STATE_COLLAPSED
    }
}

Answer 1

您可以使用EventBus开源库订阅和发布事件。

https://greenrobot.org/eventbus/

用于发布事件

 //In fragment
 EventBus.getDefault().post(new MessageEvent());

//In Activity
@Subscribe(threadMode = ThreadMode.MAIN)  
public void onMessageEvent(MessageEvent event) {/* Do something */};

public static class MessageEvent { /* Additional fields if needed */ }