写一个安卓记账本的程序

以下是一个简单的安卓记账本程序的示例：

1. 创建数据库：

在应用程序中创建SQLite数据库并创建相应的表格。

public class DBHelper extends SQLiteOpenHelper {
    private static final String DB_NAME = "account.db";
    private static final int DB_VERSION = 1;
    // 用户表
    private static final String TABLE_USER = "user";
    private static final String USER_ID = "id";
    private static final String USER_NAME = "name";
    private static final String USER_PASSWORD = "password";
    // 账单表
    private static final String TABLE_BILL = "bill";
    private static final String BILL_ID = "id";
    private static final String BILL_TYPE = "type";
    private static final String BILL_AMOUNT = "amount";
    private static final String BILL_DATE = "date";

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        // 创建用户表
        db.execSQL("CREATE TABLE " + TABLE_USER + " ("
                + USER_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
                + USER_NAME + " TEXT,"
                + USER_PASSWORD + " TEXT)");
        // 创建账单表
        db.execSQL("CREATE TABLE " + TABLE_BILL + " ("
                + BILL_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
                + BILL_TYPE + " INTEGER,"
                + BILL_AMOUNT + " REAL,"
                + BILL_DATE + " TEXT)");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // 数据库升级操作
    }
}

2. 创建登录/注册界面：

在安卓应用程序中，登录和注册界面是非常常见的。通常情况下，注册界面包括用户名、密码和确认密码等输入框，用户需要输入相应的信息进行注册。登录界面包括用户名和密码的输入框，用户需要输入正确的用户名和密码才能登录。

public class LoginActivity extends AppCompatActivity {
    private EditText mEtUserName;
    private EditText mEtPassword;

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

        mEtUserName = findViewById(R.id.et_user_name);
        mEtPassword = findViewById(R.id.et_password);

        Button btnLogin = findViewById(R.id.btn_login);
        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String userName = mEtUserName.getText().toString();
                String password = mEtPassword.getText().toString();
                // 验证用户名和密码是否正确
                if (checkUser(userName, password)) {
                    // 登录成功，跳转到主界面
                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                    startActivity(intent);
                    finish();
                } else {
                    // 登录失败，弹出提示框
                    Toast.makeText(LoginActivity.this, "用户名或密码错误", Toast.LENGTH_SHORT).show();
                }
            }
        });

        TextView tvRegister = findViewById(R.id.tv_register);
        tvRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 跳转到注册界面
                Intent intent = new Intent(LoginActivity.this, RegisterActivity.class);
                startActivity(intent);
            }
        });
    }

    private boolean checkUser(String userName, String password) {
        // 验证用户名和密码是否正确
        return false;
    }
}

public class RegisterActivity extends AppCompatActivity {
    private EditText mEtUserName;
    private EditText mEtPassword;
    private EditText mEtConfirmPassword;

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

        mEtUserName = findViewById(R.id.et_user_name);
        mEtPassword = findViewById(R.id.et_password);
        mEtConfirmPassword = findViewById(R.id.et_confirm_password);

        Button btnRegister = findViewById(R.id.btn_register);
        btnRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String userName = mEtUserName.getText().toString();
                String password = mEtPassword.getText().toString();
                String confirmPassword = mEtConfirmPassword.getText().toString();
                // 验证输入的信息是否正确
                if (!TextUtils.isEmpty(userName) && !TextUtils.isEmpty(password)
                        && password.equals(confirmPassword)) {
                    // 注册成功，将用户信息保存到数据库中
                    saveUser(userName, password);
                    Toast.makeText(RegisterActivity.this, "注册成功", Toast.LENGTH_SHORT).show();
                    finish();
                } else {
                    // 注册失败，弹出提示框
                    Toast.makeText(RegisterActivity.this, "注册失败，请检查输入的信息", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    private void saveUser(String userName, String password) {
        // 将用户信息保存到数据库中
    }
}

3. 创建主界面：

安卓记账本的主界面包括账单列表、记账按钮、分类统计、预算管理等功能。用户可以在此界面中进行查看账单、新增账单、分类统计等操作。

public class MainActivity extends AppCompatActivity {
    private List<Bill> mBillList = new ArrayList<>();
    private BillAdapter mAdapter;

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

        RecyclerView recyclerView = findViewById(R.id.recycler_view);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        mAdapter = new BillAdapter(mBillList);
        recyclerView.setAdapter(mAdapter);

        Button btnAddBill = findViewById(R.id.btn_add_bill);
        btnAddBill.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 跳转到新增账单界面
                Intent intent = new Intent(MainActivity.this, AddBillActivity.class);
                startActivityForResult(intent, 1);
            }
        });

        Button btnCategory = findViewById(R.id.btn_category);
        btnCategory.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 跳转到分类统计界面
                Intent intent = new Intent(MainActivity.this, CategoryActivity.class);
                startActivity(intent);
            }
        });

        Button btnBudget = findViewById(R.id.btn_budget);
        btnBudget.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 跳转到预算管理界面
                Intent intent = new Intent(MainActivity.this, BudgetActivity.class);
                startActivity(intent);
            }
        });

        // 加载账单数据
        loadBills();
    }

    private void loadBills() {
        mBillList.clear();
        // 从数据库中加载账单数据
        // ...
        // 加载完成后更新列表
        mAdapter.notifyDataSetChanged();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 1 && resultCode == RESULT_OK) {
            // 刷新账单列表
            loadBills();
        }
    }
}

class BillAdapter extends RecyclerView.Adapter<BillAdapter.ViewHolder> {
    private List<Bill> mBillList;

    static class ViewHolder extends RecyclerView.ViewHolder {
        TextView tvType;
        TextView tvAmount;
        TextView tvDate;

        public ViewHolder(View view) {
            super(view);
            tvType = view.findViewById(R.id.tv_type);
            tvAmount = view.findViewById(R.id.tv_amount);
            tvDate = view.findViewById(R.id.tv_date);
        }
    }

    public BillAdapter(List<Bill> billList) {
        mBillList = billList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.bill_item, parent, false);
        ViewHolder holder = new ViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Bill bill = mBillList.get(position);
        holder.tvType.setText(bill.getType());
        holder.tvAmount.setText(String.valueOf(bill.getAmount()));
        holder.tvDate.setText(bill.getDate());
    }

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

4. 创建新增账单界面：

在新增账单界面中，用户需要选择账单类型、输入账单金额、选择日期等信息。

public class AddBillActivity extends AppCompatActivity {
    private Spinner mSpinnerType;
    private EditText mEtAmount;
    private TextView mTvDate;

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

        mSpinnerType = findViewById(R.id.spinner_type);
        mEtAmount = findViewById(R.id.et_amount);
        mTvDate = findViewById(R.id.tv_date);

        Button btnSave = findViewById(R.id.btn_save);
        btnSave.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String type = mSpinnerType.getSelectedItem().toString();
                String amount = mEtAmount.getText().toString();
                String date = mTvDate.getText().toString();
                // 保存账单信息到数据库中
                saveBill(type, amount, date);
                setResult(RESULT_OK);
                finish();
            }
        });

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

    private void showDatePickerDialog() {
        Calendar calendar = Calendar.getInstance();
        DatePickerDialog datePickerDialog = new DatePickerDialog(this,
                new DatePickerDialog.OnDateSetListener() {
                    @Override
                    public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
                        String date = year + "-" + (month + 1) + "-" + dayOfMonth;
                        mTvDate.setText(date);
                    }
                },
                calendar.get(Calendar.YEAR),
                calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH));
        datePickerDialog.show();
    }

    private void saveBill(String type, String amount, String date) {
        // 将账单信息保存到数据库中
    }
}

5. 创建分类统计界面：

在分类统计界面中，可以使用图表库来展示用户的收入和支出的分类统计信息。这里使用MPAndroidChart库来展示饼状图和柱状图。

public class CategoryActivity extends AppCompatActivity {
    private PieChart mPieChart;
    private BarChart mBarChart;

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

        mPieChart = findViewById(R.id.pie_chart);
        mBarChart = findViewById(R.id.bar_chart);

        // 加载分类统计数据
        loadCategoryData();
    }

    private void loadCategoryData() {
        // 从数据库中加载分类统计数据
        // ...
        // 加载完成后更新图表
        updatePieChart();
        updateBarChart();
    }

    private void updatePieChart() {
        mPieChart.setUsePercentValues(true);
        mPieChart.getDescription().setEnabled(false);
        mPieChart.setExtraOffsets(5, 10, 5, 5);
        mPieChart.setDrawHoleEnabled(true);
        mPieChart.setHoleColor(Color.WHITE);
        mPieChart.setTransparentCircleRadius(61f);
        mPieChart.setDrawCenterText(true);

        ArrayList<PieEntry> entries