java - 如何在android中的 Activity 之间使用EventBus

Question

在我的申请中我有两个 activities .
Activity A 和 Activity B。
进入 Activity B我有dialog当用户单击其中一个按钮时 dialog ，我想调用方法到 Activity A
我写了下面的代码，但是当点击 dialog 时按钮未调用 Activity A 中的方法。

Activity B 对话框代码:

vipDialog = new Dialog(context);
                vipDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
                vipDialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
                vipDialog.setContentView(R.layout.base_dialog);
                //Set cancellable
                vipDialog.setCancelable(false);
                //Init views
                baseDialog_logo = vipDialog.findViewById(R.id.baseDialog_logo);
                baseDialog_title = vipDialog.findViewById(R.id.baseDialog_title);
                baseDialog_desc = vipDialog.findViewById(R.id.baseDialog_desc);
                baseDialog_negativeBtn = vipDialog.findViewById(R.id.baseDialog_negativeBtn);
                baseDialog_positiveBtn = vipDialog.findViewById(R.id.baseDialog_positiveBtn);
                baseDialog_buttonsLay = vipDialog.findViewById(R.id.baseDialog_buttonsLay);
                baseDialog_cancelBtn = vipDialog.findViewById(R.id.baseDialog_cancelBtn);
                //Set weight
                baseDialog_buttonsLay.setWeightSum(2);
                baseDialog_cancelBtn.setVisibility(View.GONE);
                //Set logo
                baseDialog_logo.setImageDrawable(ContextCompat.getDrawable(context, R.drawable.dialog_vip_logo));
                //Set text
                baseDialog_title.setText(getString(R.string.trialTitle));
                baseDialog_desc.setText(getString(R.string.trialDesc));
                baseDialog_positiveBtn.setText(getString(R.string.buyVip));
                baseDialog_negativeBtn.setText(getString(R.string.detailSeeAdv));
                //Set click listeners
                baseDialog_positiveBtn.setOnClickListener(v -> {
                    EventBus.getDefault().post(new BuyPremiumUserEvent(true));
                    finish();
                });
                baseDialog_negativeBtn.setOnClickListener(v -> {
                    loadFullPageAdv(getViewContext(), BuildConfig.fullPageDetailApiKey, TapsellAdRequestOptions.CACHE_TYPE_STREAMED);
                });
                vipDialog.show();

Activity A代码:

@Override
protected void onStart() {
    super.onStart();
    EventBus.getDefault().register(this);

}

@Override
protected void onStop() {
    super.onStop();
    EventBus.getDefault().unregister(this);
}

@Subscribe(threadMode = ThreadMode.MAIN)
public void onBuyPremium(final BuyPremiumUserEvent event) {
    clickedOnBuyPremium = event.isClickOnBuyPremium();
    initBazaarUserRegistered();
    Log.e("paymentLog", "Clicked");
}

当点击对话框时，不显示 Log.e("paymentLog", "Clicked");进入日志。

我该如何解决？

Answer 1

您可能需要使用粘性事件。由于 Activity A 启动 Activity B 后，它进入后台，不再接收任何事件。

将其放入您的 Activity A 而不是 EventBus.getDefault().register(this)

@Override
public void onStart() {
  super.onStart();
  EventBus.getDefault().registerSticky(this);
}

而且您还需要像这样发布粘性事件

EventBus.getDefault().postSticky(new BuyPremiumUserEvent(true));

然后在您的订阅者中，像这样添加 sticky as true

@Subscribe(sticky = true, threadMode = ThreadMode.MAIN)
  public void onBuyPremium(final BuyPremiumUserEvent event) {
  clickedOnBuyPremium = event.isClickOnBuyPremium();
  initBazaarUserRegistered();
  Log.e("paymentLog", "Clicked");
}

这是 Sticky Events 的文档