我有一个片段A，点击一个按钮就会启动包含RecyclerView的片段B.在片段B中，单击项EventBus时，该值需要传递给片段A.但是，由于某种原因，该值永远不会到达片段A。
片段A
public class OrderSummaryFragment extends BaseFragment implements OrderSummaryView {
private static final String ARG_PARAM1 = "param1";
public static final String ACTION_BACK = OrderSummaryFragment.class.getName() + ".back";
public static final String ACTION_HIDE_ACTION_BAR = OrderSummaryFragment.class.getName() + ".hide_action_bar";
public static final String ACTION_SHOW_ACTION_BAR = OrderSummaryFragment.class.getName() + ".show_action_bar";
public static final String ACTION_CHANGE_ADDRESS = OrderSummaryFragment.class.getName() + ".select_address";
FragmentOrderSummaryBinding mBinder;
Shop mShop;
OrderSummaryPresenter mPresenter;
public OrderSummaryFragment() {
}
public static OrderSummaryFragment newInstance(Shop shop) {
OrderSummaryFragment fragment = new OrderSummaryFragment();
Bundle args = new Bundle();
args.putParcelable(ARG_PARAM1, Parcels.wrap(shop));
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
Parcelable parcelable;
parcelable = getArguments().getParcelable(ARG_PARAM1);
mShop = Parcels.unwrap(parcelable);
}
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
mBinder = DataBindingUtil.inflate(inflater, R.layout.fragment_order_summary, container, false);
mPresenter = new OrderSummaryPresenterImpl(this);
sendActionToActivity(ACTION_HIDE_ACTION_BAR);
setUIListeners();
EventBus.getDefault().register(this);
return mBinder.getRoot();
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mPresenter.loadBillingAddress(mShop);
}
@Override
public void onDestroyView() {
super.onDestroyView();
sendActionToActivity(ACTION_SHOW_ACTION_BAR);
EventBus.getDefault().unregister(this);
mPresenter.cleanup();
}
@Override
protected void setTypeface() {
mBinder.tvBackButton.setTypeface(FontManager.getInstance().getFontAwesome());
}
private void setUIListeners() {
mBinder.tvBackButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
sendActionToActivity(ACTION_BACK);
}
});
mBinder.btnChange.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
sendActionToActivity(ACTION_CHANGE_ADDRESS, mShop);
}
});
}
@Override
public void renderBillingAddress(UserInfo userInfo) {
mBinder.setUserInfo(userInfo);
if (userInfo.getAddress2().equals("")) {
mBinder.tvBillingAddress2.setVisibility(View.GONE);
}
}
@Override
public void renderPaymentTerms(List<PaymentInfo> paymentInfoList) {
}
@Override
public void renderDeliveryMethod(List<DeliveryInfo> deliveryInfoList) {
}
@Override
public void showProgress(boolean show) {
}
@Override
public void showError(Error error) {
}
private void sendActionToActivity(String action) {
if (mListener == null) {
return;
}
Bundle bundle = new Bundle();
bundle.putString(Constants.ACTION_KEY, action);
mListener.onFragmentInteraction(bundle);
}
private void sendActionToActivity(String action, Shop shop) {
if (mListener == null) {
return;
}
Bundle bundle = new Bundle();
bundle.putString(Constants.ACTION_KEY, action);
bundle.putParcelable(Constants.DATA_KEY_1, Parcels.wrap(shop));
mListener.onFragmentInteraction(bundle);
}
@Subscribe(threadMode = ThreadMode.MAIN)
public void onMessage(ShippingAddressResult event) {
UserInfo userInfo = event.getUserInfo();
Log.d("Tag", "Test" + userInfo);
}
}
片段B
public class ShippingAddressFragment extends BaseFragment implements ShippingAddressView,
ShippingAddressAdapter.OnItemInteractionListener {
private static final String ARG_PARAM1 = "param1";
public static final String ACTION_BACK = ShippingAddressFragment.class.getName() + ".back";
public static final String ACTION_HIDE_ACTION_BAR = ShippingAddressFragment.class.getName() + ".hide_action_bar";
public static final String ACTION_SHOW_ACTION_BAR = ShippingAddressFragment.class.getName() + ".show_action_bar";
public static final String ACTION_NEW_ADDRESS = ShippingAddressFragment.class.getName() + ".new_address";
FragmentShippingAddressBinding mBinder;
Shop mShop;
ShippingAddressAdapter mAdapter;
ShippingAddressPresenterImpl mPresenter;
List<UserInfo> mUserInfoList;
public ShippingAddressFragment() {
}
public static ShippingAddressFragment newInstance(Shop shop) {
ShippingAddressFragment fragment = new ShippingAddressFragment();
Bundle args = new Bundle();
args.putParcelable(ARG_PARAM1, Parcels.wrap(shop));
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
Parcelable parcelable;
parcelable = getArguments().getParcelable(ARG_PARAM1);
mShop = Parcels.unwrap(parcelable);
}
mUserInfoList = new ArrayList<>();
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
mBinder = DataBindingUtil.inflate(inflater, R.layout.fragment_shipping_address, container, false);
setUIListener();
mPresenter = new ShippingAddressPresenterImpl(this);
sendActionToActivity(ACTION_HIDE_ACTION_BAR);
mAdapter = new ShippingAddressAdapter(getContext(), mUserInfoList);
mAdapter.addOnInteractionListener(this);
LinearLayoutManager manager = new LinearLayoutManager(getContext());
mBinder.rvShippingAddress.setLayoutManager(manager);
mBinder.rvShippingAddress.addItemDecoration(new DividerItemDecoration(getActivity()));
mBinder.rvShippingAddress.setAdapter(mAdapter);
return mBinder.getRoot();
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mPresenter.loadShippingAddress(mShop);
}
@Override
public void onDestroyView() {
super.onDestroyView();
mPresenter.cleanup();
sendActionToActivity(ACTION_SHOW_ACTION_BAR);
mAdapter.removeInteractionListener();
}
@Override
protected void setTypeface() {
mBinder.tvBackButton.setTypeface(FontManager.getInstance().getFontAwesome());
}
private void setUIListener() {
mBinder.tvBackButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
sendActionToActivity(ACTION_BACK);
}
});
mBinder.fabNewAddress.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
sendActionToActivity(ACTION_NEW_ADDRESS, mShop);
}
});
}
@Override
public void onClick(UserInfo userInfo) {
selectedShippingAddress(userInfo);
sendActionToActivity(ACTION_BACK);
}
@Override
public void renderShippingAddress(List<UserInfo> userInfoList) {
mUserInfoList.clear();
mUserInfoList.addAll(userInfoList);
mAdapter.notifyDataSetChanged();
}
private void sendActionToActivity(String action) {
if (mListener == null) {
return;
}
Bundle bundle = new Bundle();
bundle.putString(Constants.ACTION_KEY, action);
mListener.onFragmentInteraction(bundle);
}
private void sendActionToActivity(String action, Shop shop) {
if (mListener == null) {
return;
}
Bundle bundle = new Bundle();
bundle.putString(Constants.ACTION_KEY, action);
bundle.putParcelable(Constants.DATA_KEY_1, Parcels.wrap(shop));
mListener.onFragmentInteraction(bundle);
}
private void sendActionToActivity(String action, Shop shop, AllCheckoutInfo allCheckoutInfo) {
if (mListener == null) {
return;
}
Bundle bundle = new Bundle();
bundle.putString(Constants.ACTION_KEY, action);
bundle.putParcelable(Constants.DATA_KEY_1, Parcels.wrap(shop));
bundle.putParcelable(Constants.DATA_KEY_2, Parcels.wrap(allCheckoutInfo));
mListener.onFragmentInteraction(bundle);
}
@Override
public void showProgress(final boolean show) {
}
@Override
public void showError(Error error) {
}
private void selectedShippingAddress(UserInfo userInfo) {
ShippingAddressResult event;
event = new ShippingAddressResult();
event.setUserInfo(userInfo);
EventBus.getDefault().post(event);
}
}
答案 0 :(得分：9)
由于您正在使用片段B替换片段A，因此在触发事件时，片段A未处于活动状态/已注册以捕获它。订阅者在被解雇时会定期查看订阅者，然后死亡。如果当时有该事件的任何订阅者，他们将收到该事件。这就是Sticky Events拯救的地方。粘性事件“坚持”。订阅者在其发布时刻之后订阅（粘贴）粘性事件仍将获得它。为此，请执行以下操作。
将EventBus.getDefault().post(event);替换为EventBus.getDefault().postSticky(event);
并使您的ShippingAdressResult订阅成为粘性：
@Subscribe(threadMode = ThreadMode.MAIN, sticky = true)
public void onMessage(ShippingAddressResult event) {
UserInfo userInfo = event.getUserInfo();
Log.d("Tag", "Test" + userInfo);
EventBus.getDefault().removeStickyEvent(stickyEvent); // don't forget to remove the sticky event if youre done with it
}
答案 1 :(得分：1)
我认为Sticky Event就是你所需要的。如果您没有任何订阅者消费活动，它将等到您订阅。当你要更换碎片时，这可能是你的情况。
EventBus.getDefault().postSticky(event);
如果您不再需要此活动，请不要忘记将其删除。
EventBus.getDefault().removeStickyEvent(stickyEvent);