如何从列表中获取子项目并在Android Studio中打印

Question

我在android studio中有一个带有联系人子项的用户名列表，我只想访问列表中的联系人，但是我不能这样做，因为我的自定义列表适配器将项目和子项都保存为一个值。如何仅从列表中获取没有用户名的联系人？

模型类

public class Contact {

String contactName;
String contactNum;
String id;

public Contact() {

}

public Contact(String contactName,String id,String contactNum) {
    this.contactName=contactName;
    this.contactNum = contactNum;
    this.id = id;
}
public Contact(String contactNum) {
    this.contactNum = contactNum;
}

public String getContactName() {
    return contactName;
}

public String getContactNum() {
    return contactNum;
}
}

主要活动

public class MainActivity extends AppCompatActivity {

EditText editTextName, editTextContact;
Button buttonAdd, prevAc;
ListView listViewContacts;
List<Contact> contactList;
List<Contact> numList;
TextView textViewContact;
DatabaseReference databaseArtists;
ArrayList arrayList = new ArrayList();
Number number = new Number();
String name;
View v;


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


    databaseArtists = FirebaseDatabase.getInstance().getReference("Trusted Contacts");

    editTextName = findViewById(R.id.editTextName);
    editTextContact = findViewById(R.id.editTextContact);
    prevAc = findViewById(R.id.prevAc);
    buttonAdd = findViewById(R.id.buttonAddContact);
    listViewContacts = findViewById(R.id.listViewContacts);


    contactList = new ArrayList<>();
    numList = new ArrayList<>();
    v = getLayoutInflater().inflate(R.layout.list_layout, null);
    textViewContact = v.findViewById(R.id.value1);
    prevAc.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Contact contact1 = new Contact();
            for(int i=0;i<listViewContacts.getAdapter().getCount();i++){
                Intent callIntent = new Intent(Intent.ACTION_CALL);
                callIntent.setData(Uri.parse("tel: " + listViewContacts.getAdapter().getItem(0)));
                if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
                    Toast.makeText(getApplicationContext(), "permission denied", Toast.LENGTH_LONG).show();
                } else {
                    startActivity(callIntent);
                    dissConnectCall(MainActivity.this);
                    //    timer1();
                }
            }
            prevAc.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                      //  timer2();


                }
            });
        }
    });

    buttonAdd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            addContact();
        }
    });
}

@Override
protected void onStart() {
    super.onStart();
    databaseArtists.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            contactList.clear();
            for (DataSnapshot artistSnapshot : dataSnapshot.getChildren()) {
                Contact contact = artistSnapshot.getValue(Contact.class);
                contactList.add(contact);
            }
            ArtistList adapter = new ArtistList(MainActivity.this, contactList);
            listViewContacts.setAdapter(adapter);
        }


        @Override
        public void onCancelled(DatabaseError databaseError) {
        }
    });
}


private void addContact() {
    String name = editTextName.getText().toString();
    String contact = editTextContact.getText().toString();


    if (!TextUtils.isEmpty(name) && !TextUtils.isEmpty(contact)) {
        if (contact.length() == 11) {
            String id = databaseArtists.push().getKey();
            Contact contact1 = new Contact(name,id,contact);

            databaseArtists.child(id).setValue(contact1);




            Toast.makeText(MainActivity.this, "Contact added", Toast.LENGTH_LONG).show();


        } else {
            Toast.makeText(MainActivity.this, "Contact Number should be of 11 digits", Toast.LENGTH_LONG).show();
        }
    } else {

        Toast.makeText(MainActivity.this, "Fields cannot be empty", Toast.LENGTH_LONG).show();
    }
}

public boolean dissConnectCall(final Context activity) {
    Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            try {
                TelephonyManager telephonyManager = (TelephonyManager) activity.getSystemService(Context.TELEPHONY_SERVICE);

                Class classTelephony = Class.forName(telephonyManager.getClass().getName());
                Method methodGetITelephony = classTelephony.getDeclaredMethod("getITelephony");

                methodGetITelephony.setAccessible(true);

                Object telephonyInterface = methodGetITelephony.invoke(telephonyManager);

                Class telephonyInterfaceClass = Class.forName(telephonyInterface.getClass().getName());
                Method methodEndCall = telephonyInterfaceClass.getDeclaredMethod("endCall");

                methodEndCall.invoke(telephonyInterface);

            } catch (Exception ex) { // Many things can go wrong with reflection calls
                ex.printStackTrace();
                  return false;
            }
                  return true;
            }
         }, 4000);
       return false;
     }

列表适配器

public class ArtistList extends ArrayAdapter<Contact> {

private Activity context;
private List<Contact> contactList;

public ArtistList(Activity context,List<Contact> contactList) {
    super(context, R.layout.list_layout, contactList);

    this.context = context;
    this.contactList = contactList;
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    LayoutInflater inflater = context.getLayoutInflater();

    View listViewItem = inflater.inflate(R.layout.list_layout,null,true);

    TextView textViewName = listViewItem.findViewById(R.id.title);
    TextView textViewContact = listViewItem.findViewById(R.id.value1);

    Contact contact = contactList.get(position);

    textViewName.setText(contact.getContactName());
    textViewContact.setText(contact.getContactNum());
    return listViewItem;
}
}

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