android studio通讯录制作代码

以下是一个简单的Android Studio通讯录应用程序的制作代码示例，其中包括SQLite数据库的使用和基本的CRUD操作：

1. 首先，创建一个新的Android Studio项目，并在应用程序中添加以下依赖项：

dependencies {
    implementation 'androidx.appcompat:appcompat:1.3.1'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.0'
    implementation 'androidx.recyclerview:recyclerview:1.2.1'
    implementation 'androidx.cardview:cardview:1.0.0'
    implementation 'com.google.android.material:material:1.4.0'
    implementation 'androidx.navigation:navigation-fragment:2.3.5'
    implementation 'androidx.navigation:navigation-ui:2.3.5'
    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
    implementation 'androidx.room:room-runtime:2.3.0'
    annotationProcessor 'androidx.room:room-compiler:2.3.0'
}

2. 在应用程序中创建一个名为"Contact"的Java类，该类表示一个联系人对象，包括以下属性：姓名，电话号码和电子邮件地址。例如：

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

    public Contact(int id, String name, String phone, String email) {
        this.id = id;
        this.name = name;
        this.phone = phone;
        this.email = email;
    }

    public int getId() {
        return id;
    }

    public void setId(int 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;
    }

    public String getEmail() {
        return email;
    }

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

3. 创建一个SQLiteOpenHelper类，用于创建和管理SQLite数据库。例如：

public class DatabaseHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "contacts.db";
    private static final int DATABASE_VERSION = 1;

    private static final String TABLE_NAME = "contacts";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_NAME = "name";
    private static final String COLUMN_PHONE = "phone";
    private static final String COLUMN_EMAIL = "email";

    private static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + "(" +
            COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
            COLUMN_NAME + " TEXT," +
            COLUMN_PHONE + " TEXT," +
            COLUMN_EMAIL + " TEXT" + ")";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }
}

4. 创建一个ContactDAO类，用于定义与数据库交互的所有方法。例如：

public class ContactDAO {
    private SQLiteDatabase database;
    private DatabaseHelper dbHelper;

    public ContactDAO(Context context) {
        dbHelper = new DatabaseHelper(context);
    }

    public void open() throws SQLException {
        database = dbHelper.getWritableDatabase();
    }

    public void close() {
        dbHelper.close();
    }

    public void addContact(Contact contact) {
        ContentValues values = new ContentValues();
        values.put(DatabaseHelper.COLUMN_NAME, contact.getName());
        values.put(DatabaseHelper.COLUMN_PHONE, contact.getPhone());
        values.put(DatabaseHelper.COLUMN_EMAIL, contact.getEmail());

        database.insert(DatabaseHelper.TABLE_NAME, null, values);
    }

    public void updateContact(Contact contact) {
        ContentValues values = new ContentValues();
        values.put(DatabaseHelper.COLUMN_NAME, contact.getName());
        values.put(DatabaseHelper.COLUMN_PHONE, contact.getPhone());
        values.put(DatabaseHelper.COLUMN_EMAIL, contact.getEmail());

        database.update(DatabaseHelper.TABLE_NAME, values,
                DatabaseHelper.COLUMN_ID + " = ?", new String[] { String.valueOf(contact.getId()) });
    }

    public void deleteContact(Contact contact) {
        database.delete(DatabaseHelper.TABLE_NAME,
                DatabaseHelper.COLUMN_ID + " = ?", new String[] { String.valueOf(contact.getId()) });
    }

    public List<Contact> getAllContacts() {
        List<Contact> contacts = new ArrayList<>();

        Cursor cursor = database.query(DatabaseHelper.TABLE_NAME,
                new String[] { DatabaseHelper.COLUMN_ID, DatabaseHelper.COLUMN_NAME,
                        DatabaseHelper.COLUMN_PHONE, DatabaseHelper.COLUMN_EMAIL },
                null, null, null, null, null);

        if (cursor.moveToFirst()) {
            do {
                Contact contact = new Contact(
                        cursor.getInt(cursor.getColumnIndex(DatabaseHelper.COLUMN_ID)),
                        cursor.getString(cursor.getColumnIndex(DatabaseHelper.COLUMN_NAME)),
                        cursor.getString(cursor.getColumnIndex(DatabaseHelper.COLUMN_PHONE)),
                        cursor.getString(cursor.getColumnIndex(DatabaseHelper.COLUMN_EMAIL))
                );
                contacts.add(contact);
            } while (cursor.moveToNext());
        }
        cursor.close();

        return contacts;
    }

    public Contact getContactById(int id) {
        Cursor cursor = database.query(DatabaseHelper.TABLE_NAME,
                new String[] { DatabaseHelper.COLUMN_ID, DatabaseHelper.COLUMN_NAME,
                        DatabaseHelper.COLUMN_PHONE, DatabaseHelper.COLUMN_EMAIL },
                DatabaseHelper.COLUMN_ID + " = ?", new String[] { String.valueOf(id) },
                null, null, null);

        Contact contact = null;
        if (cursor.moveToFirst()) {
            contact = new Contact(
                    cursor.getInt(cursor.getColumnIndex(DatabaseHelper.COLUMN_ID)),
                    cursor.getString(cursor.getColumnIndex(DatabaseHelper.COLUMN_NAME)),
                    cursor.getString(cursor.getColumnIndex(DatabaseHelper.COLUMN_PHONE)),
                    cursor.getString(cursor.getColumnIndex(DatabaseHelper.COLUMN_EMAIL))
            );
        }
        cursor.close();

        return contact;
    }
}

5. 创建MainActivity类，用于显示所有联系人的列表视图。例如：

public class MainActivity extends AppCompatActivity {
    private RecyclerView recyclerView;
    private ContactAdapter adapter;
    private List<Contact> contacts = new ArrayList<>();
    private ContactDAO contactDAO;

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

        recyclerView = findViewById(R.id.recycler_view);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        adapter = new ContactAdapter(this, contacts);
        recyclerView.setAdapter(adapter);

        contactDAO = new ContactDAO(this);
        contactDAO.open();
        contacts.addAll(contactDAO.getAllContacts());
        adapter.notifyDataSetChanged();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        contactDAO.close();
    }

    public void addContact(View view) {
        Intent intent = new Intent(this, AddContactActivity.class);
        startActivity(intent);
    }

    public void editContact(View view) {
        int position = recyclerView.getChildAdapterPosition(view);
        Contact contact = contacts.get(position);
        Intent intent = new Intent(this, EditContactActivity.class);
        intent.putExtra("id", contact.getId());
        startActivity(intent);
    }

    public void deleteContact(View view) {
        int position = recyclerView.getChildAdapterPosition(view);
        Contact contact = contacts.get(position);
        contactDAO.deleteContact(contact);
        contacts.remove(contact);
        adapter.notifyItemRemoved(position);
    }
}

6. 创建一个ContactAdapter类，用于将联系人列表显示为RecyclerView。例如：

public class ContactAdapter extends RecyclerView.Adapter<ContactAdapter.ViewHolder> {
    private List<Contact> contacts;
    private LayoutInflater inflater;

    public ContactAdapter(Context context, List<Contact> contacts) {
        this.contacts = contacts;
        this.inflater = LayoutInflater.from(context);
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.contact_item, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Contact contact = contacts.get(position);
        holder.nameTextView.setText(contact.getName());
        holder.phoneTextView.setText(contact.getPhone());
        holder.emailTextView.setText(contact.getEmail());
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView nameTextView;
        public TextView phoneTextView;
        public TextView emailTextView;

        public ViewHolder(View itemView) {
            super(itemView);
            nameTextView = itemView.findViewById(R.id.name_text_view);
            phoneTextView = itemView.findViewById(R.id.phone_text_view);
            emailTextView = itemView.findViewById(R.id.email_text_view);
        }
    }
}

7. 创建AddContactActivity类，用于处理添加新联系人的表单。例如：

public class AddContactActivity extends AppCompatActivity {
    private ContactDAO contactDAO;

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

        contactDAO = new ContactDAO(this);
        contactDAO.open();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        contactDAO.close();
    }

    public void saveContact(View view) {
        EditText nameEditText = findViewById(R.id.name_edit_text);
        EditText phoneEditText = findViewById(R.id.phone_edit_text);
        EditText emailEditText = findViewById(R.id.email_edit_text);

        String name = nameEditText.getText().toString();
        String phone = phoneEditText.getText().toString();
        String email = emailEditText.getText().toString();

        Contact contact = new Contact(0, name, phone, email);
        contactDAO.addContact(contact);

        finish();
    }
}

8. 最后，创建布局文件和其他必要的资源文件。

以上是一个简单的Android Studio通讯录应用程序的制作代码示例。希望这些信息可以帮助您开始开发您自己的通讯录应用程序。