创建＆＃34; if语句＆＃34;或＆＃34;切换声明＆＃34;基于浮动动作按钮图像资源

Question

这应该是一个简单的问题。

我试图创建一个＆＃34; if语句＆＃34;或＆＃34;切换声明＆＃34;基于可绘制文件夹中的浮动操作按钮图像资源。

我在ActivityMain文件和activity_main.xml文件中编写了一个浮动操作按钮。

在ActivityMain中我只在tab.getPosition（）== 2时显示我的fab。所以它只显示在5个片段中的1个中。在这1个片段中，我有两个标签。

下面是片段代码和我的具体问题。谢谢你的帮助。非常感谢。

public class PageMessageFragment extends Fragment {

private RecyclerView recyclerView;
private View view;
private TabLayout chat_tabs;
private SearchView search;
public FloatingActionButton fab;

// Random Model
private List<Friend> items_friend = new ArrayList<>();

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    view = inflater.inflate(R.layout.page_fragment_message, container, false);

    // activate fragment menu
    setHasOptionsMenu(true);

    // Random Model
    List<Friend> items = Constant.getFriendsData(getActivity());
    items_friend = items.subList(0, 4); // Actual friends list
    fab = (FloatingActionButton) getActivity().findViewById(R.id.fab); // Gets fab ID from activity_main.xml

    recyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    recyclerView.setHasFixedSize(true);

    chat_tabs = (TabLayout) view.findViewById(R.id.chat_tabs);
    chat_tabs.addTab(chat_tabs.newTab().setText("MESSAGES"), true);
    chat_tabs.addTab(chat_tabs.newTab().setText("GROUP"));

    chat_tabs.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            if(tab.getPosition()==0){
                showListMessages(); // Actual Friends List
                fab.setImageResource(R.drawable.ic_create);
            }else if(tab.getPosition()==1){
                showListGroups();
                fab.setImageResource(R.drawable.ic_add_group);
            }
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {}
        @Override
        public void onTabReselected(TabLayout.Tab tab) {}

    });

    showListMessages();
    //fab.show();
    return view;
}

/* This is one thing that I tried, but cant seem to get it to work correctly. The if statement doesnt work
 * and always displays the snackbar. What Im trying to do is execute ActivitySelectFriend based on the
  * fab.setImageResource file. Which changes depending on the tab Im in. So if Im in "Tab Messages" I want
  * display the Activity. If Im on "Tab Group" I want to just display a snackbar for now. */
@Override
public void onViewCreated (final View view, Bundle savedInstanceState) {
    final FloatingActionButton fab1 = (FloatingActionButton) getActivity().findViewById(R.id.fab); // Gets fab ID from activity_main.xml
     /*
    fab1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(fab1.getDrawable() == R.drawable.ic_create) {
                Intent i = new Intent(v.getContext(), ActivitySelectFriend.class);
                startActivity(i);
            } else {
                Snackbar.make(view, "Select Group", Snackbar.LENGTH_SHORT).show();
            }

        }
    }); */
}