实现简单通讯录的Android Studio代码

以下是一个简单通讯录的Android Studio代码实现：

1. 首先，在Android Studio中创建一个新项目，然后在布局文件中添加一个ListView组件和一个FloatingActionButton组件。

2. 接下来，创建一个Contact类来表示通讯录中的联系人，包括姓名和电话号码。

public class Contact {
    private String name;
    private String phoneNumber;

    public Contact(String name, String phoneNumber) {
        this.name = name;
        this.phoneNumber = phoneNumber;
    }

    public String getName() {
        return name;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }
}

3. 然后，创建一个自定义的ListAdapter类来将联系人列表显示在ListView中。

public class ContactListAdapter extends ArrayAdapter<Contact> {
    private Context mContext;
    private int mResource;

    public ContactListAdapter(Context context, int resource, List<Contact> objects) {
        super(context, resource, objects);
        mContext = context;
        mResource = resource;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        if (convertView == null) {
            LayoutInflater inflater = LayoutInflater.from(mContext);
            convertView = inflater.inflate(mResource, parent, false);
        }

        TextView nameTextView = convertView.findViewById(R.id.nameTextView);
        TextView phoneNumberTextView = convertView.findViewById(R.id.phoneNumberTextView);

        Contact contact = getItem(position);

        nameTextView.setText(contact.getName());
        phoneNumberTextView.setText(contact.getPhoneNumber());

        return convertView;
    }
}

4. 接下来，在MainActivity类中创建一个ArrayList来存储联系人，并将其添加到ListView中。

public class MainActivity extends AppCompatActivity {
    private ArrayList<Contact> mContactList = new ArrayList<>();
    private ContactListAdapter mAdapter;

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

        ListView contactListView = findViewById(R.id.contactListView);
        mAdapter = new ContactListAdapter(this, R.layout.contact_list_item, mContactList);
        contactListView.setAdapter(mAdapter);

        FloatingActionButton addContactButton = findViewById(R.id.addContactButton);
        addContactButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 添加联系人的代码
            }
        });
    }
}

5. 最后，在FloatingActionButton的点击事件中添加联系人的代码，将新联系人添加到ArrayList中，并通知ListAdapter更新ListView。

addContactButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle("添加联系人");

        View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.dialog_add_contact, null);
        final EditText nameEditText = view.findViewById(R.id.nameEditText);
        final EditText phoneNumberEditText = view.findViewById(R.id.phoneNumberEditText);

        builder.setView(view);

        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                String name = nameEditText.getText().toString();
                String phoneNumber = phoneNumberEditText.getText().toString();

                Contact contact = new Contact(name, phoneNumber);
                mContactList.add(contact);
                mAdapter.notifyDataSetChanged();
            }
        });

        builder.setNegativeButton("取消", null);

        builder.show();
    }
});