如何解决 android 中片段的排序和数据显示问题？

Question

我正在学习 Android 自己。现在，我正在尝试学习片段。在这里，我想在联系人 activity.

上托管片段

我有 2 个问题

问题 1： 详细信息片段未显示所有数据。

例如来自我的 java class 。有新联系人("Ron", "Thal", "+405-315-2827", "ron@ronthal.com")

名单上有 Thal，姓氏。单击它应该显示名字、姓氏、phone 和电子邮件。但它只显示名字但有问题 2

问题 2： 我已经成功地在列表片段上按字母顺序对姓氏进行排序。但是，当我在列表片段上使用排序列表时，它没有在详细信息片段上显示正确的数据。详细片段显示片段数据的顺序是我在纯 java class 中的顺序。它应该显示要列出的相关数据。

当我不排序时，会显示正确的数据，但在单击列表片段上的姓氏时，详细信息片段上只有名字。

如何解决？我哪里弄错了？

联系activity

public class ContactActivity extends Activity implements ContactListFragment.ContactListListener{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_contact);

    }

    @Override
    public void itemClicked(long id){
        //method also defined in the listener

        View fragmentContainer = findViewById(R.id.fragment_detail_container);
        if (fragmentContainer != null){
            ContactDetailsFragment detailsFragment = new ContactDetailsFragment();
            FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
            detailsFragment.setContact(id);
            fragmentTransaction.replace(R.id.fragment_detail_container, detailsFragment);
            //fragmentTransaction.addToBackStack(null);
            fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            fragmentTransaction.commit();
        }

    }

}

联系方式片段

public class ContactDetailsFragment extends Fragment {
    private long contactId;

    public ContactDetailsFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        if (savedInstanceState != null){
            contactId = savedInstanceState.getLong("contactId");
        }
    }


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

        return inflater.inflate(R.layout.fragment_contact_details, container, false);
    }

    @Override
    public void onStart(){
        super.onStart();
        View view = getView();
        if (view != null){

            TextView FNameText = (TextView) view.findViewById(R.id.textFName);
            Contact contact = myContact[(int) contactId];
            FNameText.setText(contact.getFName());
            TextView LNameText = (TextView) view.findViewById(R.id.textLName);
            LNameText.setText(contact.getLName());
            TextView PhoneText = (TextView) view.findViewById(R.id.textPhone);
            PhoneText.setText(contact.getPhone());
            TextView EmailText = (TextView) view.findViewById(R.id.textEmail);
            EmailText.setText(contact.getEmail());

        }
    }
    @Override
    public void onSaveInstanceState(Bundle savedInstanceState){
        savedInstanceState.putLong("contactId", contactId);
    }

    public void setContact(long id){
        this.contactId = id;
    }

}

联系人列表片段

public class ContactListFragment extends ListFragment {

    //ArrayAdapter<Contact> cAdapter;
    ArrayAdapter<String> cAdapter;


    interface ContactListListener{
        void itemClicked(long id);
    }
    //add listener to fragment
    private ContactListListener listener;

    public ContactListFragment() {
        // Required empty public constructor
    }


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

        //String[] lastname = new String[Contact.class]
        //cAdapter = new ArrayAdapter<>(inflater.getContext(), R.layout.fragment_contact_list, myContact);

        String[] lnames = new String[Contact.myContact.length];
        //String[] fnames = new String[Contact.myContact.length];
        for (int i = 0; i < lnames.length; i++){
            lnames[i] = Contact.myContact[i].getLName();
            //fnames[i] = myContact[i].getFName();

        }


        //ArrayAdapter<String> cAdapter;
        //ArrayAdapter<String> cAdapter;

        //cAdapter = new ArrayAdapter<>(inflater.getContext(), android.R.layout.simple_list_item_1, myContact);
        cAdapter = new ArrayAdapter<>(inflater.getContext(), android.R.layout.simple_list_item_1, lnames);
        //to sort alphabetically
        /*
        cAdapter.sort(new Comparator<Contact>() {
            @Override
            public int compare(Contact o1, Contact o2) {
                return o1.toString().compareToIgnoreCase(o2.toString());
            }
        });
        */

        cAdapter.sort(new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {

                return o1.compareTo(o2);
            }
        });

        setListAdapter(cAdapter);
        cAdapter.notifyDataSetChanged();

        return super.onCreateView(inflater, container, savedInstanceState);
    }
    @Override
    public void onAttach(Activity activity){
        super.onAttach(activity);
        this.listener = (ContactListListener) activity;
    }
    @Override
    public void onListItemClick(ListView l, View v, int position, long id){
        if (listener != null){
            listener.itemClicked(id);
        }
    }
}

片段联系方式xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text=""
        android:id="@+id/textFName"
        />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text=""
        android:id="@+id/textLName"
        />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text=""
        android:id="@+id/textPhone"
        />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text=""
        android:id="@+id/textEmail"
        />
</LinearLayout>

联系activityxml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_contact"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:baselineAligned="false"
    tools:context="edu.uco.rawal.p5rabina.ContactActivity">
        <fragment
            class="edu.uco.rawal.p5rabina.ContactListFragment"
            android:layout_width="0dp"
            android:layout_weight ="1"
            android:layout_height="match_parent"
            android:id="@+id/contact_list_frag"/>


        <FrameLayout
            android:id="@+id/fragment_detail_container"
            android:layout_width="0dp"
            android:layout_weight="2"
            android:layout_height="match_parent"
            >

        </FrameLayout>

</LinearLayout>

Contact.java（纯javaclass）

public class Contact {
    private String fname, lname, phone, email;


    public static final Contact[] myContact = {

            new Contact("Rabin", "Awal", "+405-315-0007", "rawal@yahoo.com"),
            new Contact("David", "Gilmour", "+405-315-2027", "david@gilmour.com"),
            new Contact("James", "Hetfield", "+405-315-2527", "james@metallica.com"),
            new Contact("Kirk", "Hammet", "+405-315-2995", "kirk@metallica.com"),
            new Contact("Tom", "Morello", "+405-315-2886", "tom@tommorello.com"),
            new Contact("Angus", "Young", "+405-315-2831", "angus@acdc.com.au"),
            new Contact("Ron", "Thal", "+405-315-2827", "ron@ronthal.com")
    };



    private Contact(String fname, String lname, String phone, String email){
        this.fname = fname;
        this.lname = lname;
        this.email = email;
        this.phone = phone;
    }

    public String getFName() {
        return fname;
    }

    public String getLName() {
        return lname;
    }

    public String getEmail() {
        return email;
    }

    public String getPhone() {
        return phone;
    }
    /*

    public void setFName(String fname) {
        this.fname = fname;
    }

    public void setLName(String lname) {
        this.lname = lname;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public void setEmail(String email) {
        this.email = email;
    }
    */

    @Override
    public String toString() {
        //return super.toString();


        return  fname.toString();
        //return this.fname;

    }


}

谢谢

Answer 1

it is displaying only first name

在 ListView 中，这是有道理的，因为 ArrayAdapter<String> 将 toString 您的对象，即 return fname.toString();（实际上可能只是 return fname）

如果你的意思是在细节片段内部，那么在你的 XML 中，每个 TextView 理想情况下应该有 android:layout_height="wrap_content" 而不是 match_parent。否则一个TextView占满一屏

I have successfully sorted Lastnames alphabetically on the list fragment.

好的，那么我不确定问题出在哪里...也许您的意思是这就是问题所在？

cAdapter.sort(new Comparator<Contact>() {
    @Override
    public int compare(Contact o1, Contact o2) {
        return o1.toString().compareToIgnoreCase(o2.toString());
    }
});

这里有两个 Contact 对象...如果您想按姓氏排序，请执行此操作。

cAdapter.sort(new Comparator<Contact>() {
    @Override
    public int compare(Contact c1, Contact c2) {
        return c1.getLName().compareToIgnoreCase(c2.getLName());
    }
});

关于这段代码。

   String[] lnames = new String[Contact.myContact.length];
    //String[] fnames = new String[Contact.myContact.length];
    for (int i = 0; i < lnames.length; i++){
        lnames[i] = Contact.myContact[i].getLName();
        //fnames[i] = myContact[i].getFName();

    }

如果您想显示 Contact 的所有信息而不仅仅是 last/first 名称，我建议您尝试查找如何创建 ArrayAdapter<Contact>。

我也不太确定在 onStart() 中使用 getView()...我认为您应该使用 onCreateView 或 onViewCreated 中的视图。

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