记账本android studio实现

1. 首先，在Android Studio中创建一个新的项目。

2. 在项目的build.gradle文件中添加以下依赖项：

implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support:recyclerview-v7:28.0.0'
implementation 'com.android.support:cardview-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'

3. 创建一个RecyclerView，用于显示记账记录。在activity_main.xml文件中添加以下代码：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="16dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

</android.support.constraint.ConstraintLayout>

4. 创建一个记账记录的数据类，包括金额、时间、类型等信息。

public class Record {
    private int id;
    private int amount;
    private String time;
    private String type;

    public Record(int id, int amount, String time, String type) {
        this.id = id;
        this.amount = amount;
        this.time = time;
        this.type = type;
    }

    public int getId() {
        return id;
    }

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

    public int getAmount() {
        return amount;
    }

    public void setAmount(int amount) {
        this.amount = amount;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }
}

5. 创建一个RecyclerView的适配器类，用于将记账记录数据显示在RecyclerView中。

public class RecordAdapter extends RecyclerView.Adapter<RecordAdapter.ViewHolder> {
    private List<Record> mRecordList;

    static class ViewHolder extends RecyclerView.ViewHolder {
        TextView amountTextView;
        TextView timeTextView;
        TextView typeTextView;

        public ViewHolder(View view) {
            super(view);
            amountTextView = view.findViewById(R.id.amountTextView);
            timeTextView = view.findViewById(R.id.timeTextView);
            typeTextView = view.findViewById(R.id.typeTextView);
        }
    }

    public RecordAdapter(List<Record> recordList) {
        mRecordList = recordList;
    }

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

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        Record record = mRecordList.get(position);
        holder.amountTextView.setText(String.valueOf(record.getAmount()));
        holder.timeTextView.setText(record.getTime());
        holder.typeTextView.setText(record.getType());
    }

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

6. 创建一个记账记录的数据库类，用于存储和读取记账记录数据。

public class RecordDatabaseHelper extends SQLiteOpenHelper {
    public static final String CREATE_RECORD = "create table Record ("
            + "id integer primary key autoincrement, "
            + "amount integer, "
            + "time text, "
            + "type text)";

    public RecordDatabaseHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
    }

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

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("drop table if exists Record");
        onCreate(db);
    }

    public void addRecord(Record record) {
        SQLiteDatabase db = getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put("amount", record.getAmount());
        values.put("time", record.getTime());
        values.put("type", record.getType());
        db.insert("Record", null, values);
        db.close();
    }

    public void deleteRecord(int id) {
        SQLiteDatabase db = getWritableDatabase();
        db.delete("Record", "id=?", new String[]{String.valueOf(id)});
        db.close();
    }

    public List<Record> getAllRecords() {
        List<Record> recordList = new ArrayList<>();
        SQLiteDatabase db = getReadableDatabase();
        Cursor cursor = db.query("Record", null, null, null, null, null, null);
        if (cursor.moveToFirst()) {
            do {
                int id = cursor.getInt(cursor.getColumnIndex("id"));
                int amount = cursor.getInt(cursor.getColumnIndex("amount"));
                String time = cursor.getString(cursor.getColumnIndex("time"));
                String type = cursor.getString(cursor.getColumnIndex("type"));
                Record record = new Record(id, amount, time, type);
                recordList.add(record);
            } while (cursor.moveToNext());
        }
        cursor.close();
        db.close();
        return recordList;
    }
}

7. 创建一个MainActivity类，用于管理记账记录的添加、删除和显示。在onCreate方法中，实例化RecyclerView和RecordAdapter，并将适配器设置给RecyclerView。在添加按钮的点击事件中，获取用户输入的金额、时间和类型，将其保存到数据库中，并更新RecyclerView的显示。在RecyclerView的item中，添加删除按钮的点击事件，将记录从数据库中删除，并更新RecyclerView的显示。

public class MainActivity extends AppCompatActivity {
    private List<Record> mRecordList = new ArrayList<>();
    private RecordAdapter mRecordAdapter;
    private RecordDatabaseHelper mDatabaseHelper;

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

        mDatabaseHelper = new RecordDatabaseHelper(this, "Record.db", null, 1);
        mRecordList = mDatabaseHelper.getAllRecords();

        RecyclerView recyclerView = findViewById(R.id.recyclerView);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        mRecordAdapter = new RecordAdapter(mRecordList);
        recyclerView.setAdapter(mRecordAdapter);

        Button addButton = findViewById(R.id.addButton);
        addButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText amountEditText = findViewById(R.id.amountEditText);
                EditText timeEditText = findViewById(R.id.timeEditText);
                EditText typeEditText = findViewById(R.id.typeEditText);
                int amount = Integer.parseInt(amountEditText.getText().toString());
                String time = timeEditText.getText().toString();
                String type = typeEditText.getText().toString();
                Record record = new Record(0, amount, time, type);
                mDatabaseHelper.addRecord(record);
                mRecordList.clear();
                mRecordList.addAll(mDatabaseHelper.getAllRecords());
                mRecordAdapter.notifyDataSetChanged();
                amountEditText.setText("");
                timeEditText.setText("");
                typeEditText.setText("");
            }
        });
    }

    public void deleteRecord(View view) {
        int position = (int) view.getTag();
        Record record = mRecordList.get(position);
        mDatabaseHelper.deleteRecord(record.getId());
        mRecordList.remove(position);
        mRecordAdapter.notifyItemRemoved(position);
    }
}