Java 在片段之间切换的问题

我有一个活动，它有3个片段，每个片段为每个页面上的用户提取一组信息。我将其设置为列表中只有2个用户，第三个片段将重定向到第二个，如果只有1个用户，则第二个片段将在滑动到第一个时重定向

下面是我用来在片段之间切换的代码：

  Fragment mFragment = new Fragment1(); 
                         getFragmentManager().beginTransaction()
                                    .replace(R.id.Fragment1, mFragment ).commit();

下面是完整的代码

    public class Fragment2 extends Fragment {


    private String currentUserId;
    private ArrayAdapter<String> namesArrayAdapter;
    private ArrayList<String> names;
    private ListView usersListView;
    private Button logoutButton;

    String userGender = ParseUser.getCurrentUser().getString("Gender");
    String activityName = ParseUser.getCurrentUser().getString("ActivityName");
    Number maxDistance = ParseUser.getCurrentUser().getNumber("Maximum_Distance");
    String userLookingGender = ParseUser.getCurrentUser().getString("Looking_Gender");
    Number minimumAge = ParseUser.getCurrentUser().getNumber("Minimum_Age");
    Number maximumAge = ParseUser.getCurrentUser().getNumber("Maximum_Age");
    Number userage = ParseUser.getCurrentUser().getNumber("Age");

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        setConversationsList();

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment2_layout, container, false);


        return view;
    }

    private void setConversationsList() {
        currentUserId = ParseUser.getCurrentUser().getObjectId();
        names = new ArrayList<String>();
        // String userActivitySelectionName = null;

    ParseQuery<ParseUser> query = ParseUser.getQuery();

    //  query.whereEqualTo("ActivityName",userActivitySelectionName);

    query.whereNotEqualTo("objectId", ParseUser.getCurrentUser().getObjectId());
    // users with Gender = currentUser.Looking_Gender
    query.whereEqualTo("Gender", userLookingGender);
    // users with Looking_Gender = currentUser.Gender
    query.setLimit(1);
    query.setSkip(1); // will skip the first result, giving the 2nd most recent user

    query.whereEqualTo("Looking_Gender", userGender);
    query.whereEqualTo("ActivityName", activityName);
    //query.whereGreaterThanOrEqualTo("Minimum_Age", minimumAge).whereGreaterThanOrEqualTo("Age", userage);
    //query.whereLessThanOrEqualTo("Maximum_Age", maximumAge).whereLessThanOrEqualTo("Age", userage);
    //  query.whereWithinKilometers("Maximum_Distance", point, maxDistance)





    query.findInBackground(new FindCallback<ParseUser>() {

        public void done(List<ParseUser> userList, ParseException e) {
            if (e == null) {
                for (int i=0; i<userList.size(); i++) {
                    names.add(userList.get(i).get("Name").toString());
                    names.add(userList.get(i).get("Headline").toString());
                    names.add(userList.get(i).get("Age").toString());

                    //       names.add(userList.get(i).getParseObject("ProfilePicture").;


                }




                usersListView = (ListView)getActivity().findViewById(R.id.userlistview2);
                namesArrayAdapter =
                        new ArrayAdapter<String>(getActivity().getApplicationContext(),
                                R.layout.user_list_item, names);
                usersListView.setAdapter(namesArrayAdapter);

                usersListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                    @Override
                    public void onItemClick(AdapterView<?> a, View v, int i, long l) {
                        openConversation(names, i);
                    }
                });

            } else {

                 Fragment mFragment = new Fragment1(); 
                 getFragmentManager().beginTransaction()
                            .replace(R.id.Fragment1, mFragment ).commit();
            }
        }
    });
}

public void openConversation(ArrayList<String> names, int pos) {
    ParseQuery<ParseUser> query = ParseUser.getQuery();
    query.whereEqualTo("Name", names.get(pos));
    query.findInBackground(new FindCallback<ParseUser>() {
        public void done(List<ParseUser> user, ParseException e) {
            if (e == null) {
                Intent intent = new Intent(getActivity().getApplicationContext(), MessagingActivity.class);
                intent.putExtra("RECIPIENT_ID", user.get(0).getObjectId());
                startActivity(intent);
            } else {
                Toast.makeText(getActivity().getApplicationContext(),
                        "Error finding that user",
                        Toast.LENGTH_SHORT).show();
            }
        }
    });
}
}

下面是引用的第一个片段的布局

 <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@drawable/bac_blue"
        android:orientation="vertical" >

        <ListView
            android:id="@+id/userlistname"
            android:layout_width="220dp"
            android:layout_centerHorizontal="true"
            android:layout_height="50dp"
            android:divider="@null"

            >

        </ListView>
         <FrameLayout 
          android:id="@+id/Fragment1"
          android:layout_width="fill_parent" 
          android:layout_height="fill_parent" 
          android:layout_weight="1" />

        <ListView
            android:id="@+id/userlistheadline"
            android:layout_width="220dp"
            android:layout_below="@+id/userlistname"
            android:layout_centerHorizontal="true"
            android:layout_height="50dp"
            android:divider="@null"

            >

        </ListView>

         <ImageView
            android:id="@+id/profilePictureResult"
            android:layout_width="132dp"
            android:layout_height="120dp"
            android:layout_below="@+id/userlistheadline"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="7dp"
            android:layout_marginBottom="9dp"
            android:padding="3dp"
            android:scaleType="centerCrop"
            android:cropToPadding="true"
            android:background="@drawable/border_image"
            android:alpha="1" />

        <ListView
            android:id="@+id/userlistage"
            android:layout_width="220dp"
            android:layout_below="@+id/profilePictureResult"
            android:layout_centerHorizontal="true"
            android:layout_height="50dp"
            android:divider="@null"

            >

        </ListView>

         <ListView
            android:id="@+id/userlistactivityname"
            android:layout_width="220dp"
            android:layout_below="@+id/profilePictureResult"
            android:layout_centerHorizontal="true"
            android:layout_height="50dp"
            android:divider="@null"

            >

        </ListView>


        <Button
            android:id="@+id/button1"
            android:layout_below="@+id/userlistactivityname"
            android:layout_centerHorizontal="true"
            android:layout_width="100dp"
            android:layout_height="50dp"
            android:layout_marginTop="12dp"
            android:alpha="0.7"
            android:textColor="#000000"
            android:background="#ADD8E6"
            android:textSize="22sp"
            android:typeface="serif"
            android:text="Confirm" />

        <ImageView
            android:id="@+id/imageView2"
            android:layout_width="70dp"
            android:layout_height="50dp"
            android:layout_alignParentRight="true"
            android:layout_alignTop="@+id/imageView1"
            android:alpha="0.7"
            android:src="@drawable/left_right" />

        <ImageView
            android:id="@+id/imageView1"
            android:layout_width="70dp"
            android:layout_height="50dp"
            android:layout_alignBottom="@+id/userlistview"
            android:layout_alignParentLeft="true"
            android:layout_marginBottom="119dp"
            android:alpha="0.7"
            android:src="@drawable/left_arrow2" />

    </RelativeLayout>

---

提前谢谢。

您能不能让我设置的方式是，列表中只有2个用户，第三个片段会自动重定向到第二个，如果只有1个用户，第二个片段会在刷到第一个片段时自动重定向？谢谢您的回复。为了澄清它，如果在前面的片段中找不到用户，请将您重定向到该片段。每个片段由最近的一个用户返回列表上的1个用户。我不想显示空白活动这就是为什么，