一个App综合项目（结合所学知识和案例），主要包括下面内容：ꔷ 注册，登录（SQLite技术），ꔷ 记住密码（数据存储技术）ꔷ 购买武器游戏（Activity组件跳转和数据传递技术）程序代码

好的，下面是一个简单的App综合项目代码，包括注册、登录、记住密码和购买武器游戏功能。由于篇幅限制，我只提供核心代码，如有需要可以自行补充。

1. 注册和登录功能实现（使用SQLite技术）

注册页面代码：

public class RegisterActivity extends AppCompatActivity {

    EditText etUsername, etPassword, etConfirmPassword;
    Button btnRegister;
    DBHelper dbHelper;

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

        etUsername = findViewById(R.id.et_username);
        etPassword = findViewById(R.id.et_password);
        etConfirmPassword = findViewById(R.id.et_confirm_password);
        btnRegister = findViewById(R.id.btn_register);

        dbHelper = new DBHelper(this);

        btnRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String username = etUsername.getText().toString();
                String password = etPassword.getText().toString();
                String confirmPassword = etConfirmPassword.getText().toString();

                if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password) || TextUtils.isEmpty(confirmPassword)) {
                    Toast.makeText(RegisterActivity.this, "请输入用户名和密码", Toast.LENGTH_SHORT).show();
                    return;
                }

                if (!password.equals(confirmPassword)) {
                    Toast.makeText(RegisterActivity.this, "两次输入的密码不一致", Toast.LENGTH_SHORT).show();
                    return;
                }

                if (dbHelper.checkUser(username)) {
                    Toast.makeText(RegisterActivity.this, "该用户名已被注册", Toast.LENGTH_SHORT).show();
                    return;
                }

                dbHelper.addUser(username, password);
                Toast.makeText(RegisterActivity.this, "注册成功", Toast.LENGTH_SHORT).show();
                finish();
            }
        });
    }
}

登录页面代码：

public class LoginActivity extends AppCompatActivity {

    EditText etUsername, etPassword;
    Button btnLogin;
    CheckBox cbRemember;
    DBHelper dbHelper;
    SharedPreferences sp;

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

        etUsername = findViewById(R.id.et_username);
        etPassword = findViewById(R.id.et_password);
        btnLogin = findViewById(R.id.btn_login);
        cbRemember = findViewById(R.id.cb_remember);

        dbHelper = new DBHelper(this);
        sp = getSharedPreferences("user", MODE_PRIVATE);

        if (sp.getBoolean("remember_password", false)) {
            etUsername.setText(sp.getString("username", ""));
            etPassword.setText(sp.getString("password", ""));
            cbRemember.setChecked(true);
        }

        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String username = etUsername.getText().toString();
                String password = etPassword.getText().toString();

                if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
                    Toast.makeText(LoginActivity.this, "请输入用户名和密码", Toast.LENGTH_SHORT).show();
                    return;
                }

                if (!dbHelper.checkUser(username, password)) {
                    Toast.makeText(LoginActivity.this, "用户名或密码错误", Toast.LENGTH_SHORT).show();
                    return;
                }

                if (cbRemember.isChecked()) {
                    SharedPreferences.Editor editor = sp.edit();
                    editor.putString("username", username);
                    editor.putString("password", password);
                    editor.putBoolean("remember_password", true);
                    editor.apply();
                } else {
                    SharedPreferences.Editor editor = sp.edit();
                    editor.clear();
                    editor.apply();
                }

                Toast.makeText(LoginActivity.this, "登录成功", Toast.LENGTH_SHORT).show();
                startActivity(new Intent(LoginActivity.this, MainActivity.class));
                finish();
            }
        });
    }
}

2. 记住密码功能实现（使用SharedPreferences技术）

在登录页面的onCreate()方法中，我们使用SharedPreferences读取保存的用户名和密码，并将它们自动填充到输入框中：

sp = getSharedPreferences("user", MODE_PRIVATE);

if (sp.getBoolean("remember_password", false)) {
    etUsername.setText(sp.getString("username", ""));
    etPassword.setText(sp.getString("password", ""));
    cbRemember.setChecked(true);
}

在登录成功后，如果用户勾选了记住密码，我们使用SharedPreferences保存用户名和密码：

if (cbRemember.isChecked()) {
    SharedPreferences.Editor editor = sp.edit();
    editor.putString("username", username);
    editor.putString("password", password);
    editor.putBoolean("remember_password", true);
    editor.apply();
} else {
    SharedPreferences.Editor editor = sp.edit();
    editor.clear();
    editor.apply();
}

3. 购买武器游戏功能实现（使用Activity组件跳转和数据传递技术）

商品列表页面代码：

public class WeaponListActivity extends AppCompatActivity {

    ListView lvWeapon;
    List<Weapon> weaponList;

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

        lvWeapon = findViewById(R.id.lv_weapon);
        weaponList = new ArrayList<>();
        weaponList.add(new Weapon("AK47", 3000));
        weaponList.add(new Weapon("M4A1", 4000));
        weaponList.add(new Weapon("AWP", 5000));

        WeaponAdapter adapter = new WeaponAdapter(this, weaponList);
        lvWeapon.setAdapter(adapter);

        lvWeapon.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Weapon weapon = weaponList.get(position);
                Intent intent = new Intent(WeaponListActivity.this, WeaponDetailActivity.class);
                intent.putExtra("name", weapon.getName());
                intent.putExtra("price", weapon.getPrice());
                startActivity(intent);
            }
        });
    }
}

购物车页面代码：

public class ShoppingCartActivity extends AppCompatActivity {

    TextView tvTotalPrice;
    Button btnCheckout;
    List<Weapon> weaponList;

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

        tvTotalPrice = findViewById(R.id.tv_total_price);
        btnCheckout = findViewById(R.id.btn_checkout);
        weaponList = new ArrayList<>();

        Intent intent = getIntent();
        String name = intent.getStringExtra("name");
        int price = intent.getIntExtra("price", 0);
        weaponList.add(new Weapon(name, price));

        int totalPrice = 0;
        for (Weapon weapon : weaponList) {
            totalPrice += weapon.getPrice();
        }
        tvTotalPrice.setText("总价：" + totalPrice);

        btnCheckout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(ShoppingCartActivity.this, "支付成功", Toast.LENGTH_SHORT).show();
                finish();
            }
        });
    }
}

在商品列表页面中，我们使用ListView来显示商品列表。当用户点击某个商品时，我们使用Intent来传递商品的名称和价格到购物车页面：

lvWeapon.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Weapon weapon = weaponList.get(position);
        Intent intent = new Intent(WeaponListActivity.this, WeaponDetailActivity.class);
        intent.putExtra("name", weapon.getName());
        intent.putExtra("price", weapon.getPrice());
        startActivity(intent);
    }
});

在购物车页面中，我们使用Intent来接收商品的名称和价格，并将它们添加到购物车中。同时，我们还计算了购物车中所有商品的总价，并显示在页面上。

4. 数据库操作类DBHelper代码

public class DBHelper extends SQLiteOpenHelper {

    private static final String DB_NAME = "user.db";
    private static final int DB_VERSION = 1;

    private static final String TABLE_USER = "user";
    private static final String COLUMN_USERNAME = "username";
    private static final String COLUMN_PASSWORD = "password";

    public DBHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String sql = "CREATE TABLE " + TABLE_USER + " (" +
                COLUMN_USERNAME + " TEXT PRIMARY KEY," +
                COLUMN_PASSWORD + " TEXT)";
        db.execSQL(sql);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO: 升级数据库时的操作
    }

    public void addUser(String username, String password) {
        SQLiteDatabase db = getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_USERNAME, username);
        values.put(COLUMN_PASSWORD, password);
        db.insert(TABLE_USER, null, values);
        db.close();
    }

    public boolean checkUser(String username) {
        SQLiteDatabase db = getReadableDatabase();
        Cursor cursor = db.query(TABLE_USER, null, COLUMN_USERNAME + "=?", new String[]{username}, null, null, null);
        boolean exist = cursor.getCount() > 0;
        cursor.close();
        db.close();
        return exist;
    }

    public boolean checkUser(String username, String password) {
        SQLiteDatabase db = getReadableDatabase();
        Cursor cursor = db.query(TABLE_USER, null, COLUMN_USERNAME + "=? AND " + COLUMN_PASSWORD + "=?", new String[]{username, password}, null, null, null);
        boolean exist = cursor.getCount() > 0;
        cursor.close();
        db.close();
        return exist;
    }
}

这是一个简单的DBHelper类，用来创建和升级数据库，并提供了添加用户和检查用户的方法。在实际项目中，你可能需要更加完善的数据库操作。