android studio实现简单通讯录

以下是Android Studio实现简单通讯录的步骤：

1.创建一个新的Android Studio项目，选择Empty Activity模板。

2.在app/build.gradle文件中添加如下依赖项：

implementation 'com.google.android.material:material:1.2.0'

3.在activity_main.xml文件中添加一个RecyclerView和一个FloatingActionButton。

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    app:layoutManager="LinearLayoutManager"
    tools:listitem="@layout/item_contact" />

<com.google.android.material.floatingactionbutton.FloatingActionButton
    android:id="@+id/fab_add"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|end"
    android:layout_margin="16dp"
    android:src="@drawable/ic_add"
    app:backgroundTint="@color/colorAccent"
    app:tint="@android:color/white" />

4.创建一个Contact类，包含id、name和phone属性，以及相应的getter和setter方法。

public class Contact {
    private String id;
    private String name;
    private String phone;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPhone() {
        return phone;
    }

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

5.创建一个ContactAdapter类，继承自RecyclerView.Adapter，用于将Contact对象绑定到RecyclerView上。

public class ContactAdapter extends RecyclerView.Adapter<ContactAdapter.ContactViewHolder> {
    private List<Contact> contactList;

    public ContactAdapter(List<Contact> contactList) {
        this.contactList = contactList;
    }

    @NonNull
    @Override
    public ContactViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item_contact, parent, false);
        return new ContactViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(@NonNull ContactViewHolder holder, int position) {
        Contact contact = contactList.get(position);
        holder.tvName.setText(contact.getName());
        holder.tvPhone.setText(contact.getPhone());
    }

    @Override
    public int getItemCount() {
        return contactList.size();
    }

    public class ContactViewHolder extends RecyclerView.ViewHolder {
        public TextView tvName, tvPhone;

        public ContactViewHolder(View view) {
            super(view);
            tvName = view.findViewById(R.id.tv_name);
            tvPhone = view.findViewById(R.id.tv_phone);
        }
    }
}

6.创建一个MainActivity类，实现添加联系人和展示联系人列表的功能。

public class MainActivity extends AppCompatActivity {
    private List<Contact> contactList = new ArrayList<>();
    private ContactAdapter contactAdapter;
    private RecyclerView recyclerView;
    private FloatingActionButton fabAdd;

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

        recyclerView = findViewById(R.id.recycler_view);
        fabAdd = findViewById(R.id.fab_add);

        contactAdapter = new ContactAdapter(contactList);
        recyclerView.setAdapter(contactAdapter);

        fabAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                showAddDialog();
            }
        });
    }

    private void showAddDialog() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Add Contact");

        View view = LayoutInflater.from(this).inflate(R.layout.dialog_add_contact, null);
        final EditText etName = view.findViewById(R.id.et_name);
        final EditText etPhone = view.findViewById(R.id.et_phone);

        builder.setView(view);

        builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                String name = etName.getText().toString();
                String phone = etPhone.getText().toString();

                Contact contact = new Contact();
                contact.setName(name);
                contact.setPhone(phone);

                contactList.add(contact);
                contactAdapter.notifyDataSetChanged();
            }
        });

        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                dialogInterface.dismiss();
            }
        });

        builder.show();
    }
}