（6）列表数据记录record_item_layout.xml

record_item_layout.xml 主要用途是存储列表的传输数据。具体代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:layout_marginHorizontal="20dp"
        android:gravity="center_horizontal"
        android:paddingVertical="2dp">
        <TextView
            android:id="@+id/list_id"
            android:layout_width="40dp"
            android:layout_height="24dp"
            android:layout_weight="1"
            android:textSize="18sp"
            android:gravity="center_horizontal" />
        <TextView
            android:id="@+id/list_date"
            android:layout_width="90dp"
            android:layout_height="24dp"
            android:layout_weight="1"
            android:textSize="18sp"
            android:gravity="center_horizontal" />
        <TextView
            android:id="@+id/list_type"
            android:layout_width="70dp"
            android:layout_height="24dp"
            android:layout_weight="1"
            android:textSize="18sp"
            android:gravity="center_horizontal" />
        <TextView
            android:id="@+id/list_money"
            android:layout_width="70dp"
            android:layout_height="24dp"
            android:layout_weight="1"
            android:textSize="18sp"
            android:gravity="center_horizontal" />
        <TextView
            android:id="@+id/list_state"
            android:layout_width="90dp"
            android:layout_height="24dp"
            android:layout_weight="1"
            android:textSize="18sp"
            android:gravity="center_horizontal" />
    </LinearLayout>
</LinearLayout>
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3. 逻辑结构💡

写完静态页面之后，接下来我们要对每个页面的逻辑进行编写。现在我们来看一下各个 Activity 类所实现的内容都有些什么呢？

（1）DBHelper类

DBHelper 类用于创建数据库表和数据库数据，同时实现与数据库操作相关的登录和注册方法。具体代码实现如下：

package com.financial.management;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DBHelper extends SQLiteOpenHelper {
    public static final String DB_NAME = "Test.db";
    public static final String TABLE_NAME = "userinfo";
    public static final String COLUMN_USERID = "uid";
    public static final String COLUMN_USERPWD = "upwd";
    //创建数据库语句
    private static final String CREATE_TABLE = "create table if not exists "
            + TABLE_NAME + "(" + COLUMN_USERID + " text not null primary key,"
            + COLUMN_USERPWD + " text not null)";
    public DBHelper(Context context) {
        super(context, DB_NAME, null, 1);
    }
    //创建数据库方法
    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            db.execSQL(CREATE_TABLE);
            db.execSQL("insert into " + TABLE_NAME + " values('11','11')");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    //重置数据库方法(先删表，再建表)
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("drop table  if exists " + TABLE_NAME);
        db.execSQL(CREATE_TABLE);
    }
    //登录方法
    public User userlogin(String userId, String userPwd) {
        User user = null;
        SQLiteDatabase db = getReadableDatabase();
        Cursor cursor = db.query(TABLE_NAME,
                new String[]{COLUMN_USERID, COLUMN_USERPWD},
                COLUMN_USERID + "=? and " + COLUMN_USERPWD + "=?",
                new String[]{userId, userPwd},
                null,
                null,
                null);
        if (cursor.getCount() > 0) {
            cursor.moveToFirst();
            user = new User();
            user.setUserId(cursor.getString(cursor.getColumnIndex(COLUMN_USERID)));
            user.setUserPwd(cursor.getString(cursor.getColumnIndex(COLUMN_USERPWD)));
        }
        return user;
    }
    //注册方法
    public long registerUser(User user) {
        SQLiteDatabase db = getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COLUMN_USERID, user.getUserId());
        contentValues.put(COLUMN_USERPWD, user.getUserPwd());
        return db.insert(TABLE_NAME, null, contentValues);
    }
}
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（2）MainActivity类

MainActivity 类是用户登录页面的Activity，主要编写用户登录页面的代码逻辑。具体代码实现如下：

package com.financial.management;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.util.ArrayList;
//登录页面逻辑
public class MainActivity extends AppCompatActivity {
    EditText edt_id,edt_pwd;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        edt_id = findViewById(R.id.edt_uid);
        edt_pwd =findViewById(R.id.edt_upwd);
        Button btn_login = findViewById(R.id.btn_login);
        //登录按键
        btn_login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    String userId=edt_id.getText().toString();
                    String userPwd=edt_pwd.getText().toString();
                    DBHelper dbuserHelper=new DBHelper(getApplicationContext());
                    User user = dbuserHelper.userlogin(userId,userPwd);
                    //登录成功跳转对应类型界面
                    if(user!=null) {
                        Toast.makeText(getApplicationContext(), user.getUserId() + "登录成功", Toast.LENGTH_SHORT).show();
                        Intent intent;
                        ArrayList<User> list = new ArrayList<>();
                        list.add(user);
                        intent = new Intent(getApplicationContext(), UserCenterActivity.class);
                        intent.putParcelableArrayListExtra("LoginUser", list);
                        startActivity(intent);
                    }else{
                        Toast.makeText(getApplicationContext(),"登录失败，密码错误或账号不存在！",Toast.LENGTH_SHORT).show();
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                    Toast.makeText(getApplicationContext(),"数据库异常",Toast.LENGTH_SHORT).show();
                }
            }
        });
        //注册按键
        Button btn_register=findViewById(R.id.btn_register);
        btn_register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(getApplicationContext(),RegisterActivity.class);
                startActivity(intent);
            }
        });
    }
}
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（3）RegisterActivity类

RegisterActivity 类是用户注册页面的Activity，主要编写用户注册页面的业务逻辑。具体代码实现如下：

package com.financial.management;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.util.ArrayList;
//注册页面逻辑
public class RegisterActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);
        final EditText edt_rid =findViewById(R.id.edt_rid);
        final EditText edt_rpwd =findViewById(R.id.edt_rpwd);
        //注册按键
        Button btn_registerf=findViewById(R.id.btn_registeruser);
        btn_registerf.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                User user = new User();
                user.setUserId(edt_rid.getText().toString());
                user.setUserPwd(edt_rpwd.getText().toString());
                DBHelper dbUserHelper = new DBHelper(getApplicationContext());
                if (dbUserHelper.registerUser(user) > 0) {
                    Toast.makeText(getApplicationContext(), "注册成功", Toast.LENGTH_SHORT).show();
                    Intent intent;
                    ArrayList<User> list = new ArrayList<>();
                    list.add(user);
                    intent = new Intent(getApplicationContext(), MainActivity.class);
                    startActivity(intent);
                }else{
                    Toast.makeText(getApplicationContext(), "您已经注册过此账户，请返回登录", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}
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（4）UserCenterActivity类

UserCenterActivity 类是个人中心页面的Activity，主要编写个人中心各种按钮跳转的业务逻辑。具体代码实现如下：

package com.financial.management;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
//用户个人中心页面逻辑
public class UserCenterActivity extends AppCompatActivity {
    ArrayList<User> list;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_user_center);
        Intent intent=getIntent();
        list =intent.getParcelableArrayListExtra("LoginUser");
        User user=list.get(0);
        final String username=user.getUserId();
        TextView tv_welcome=findViewById(R.id.tv_welcome);
        tv_welcome.setText("欢迎您 ,用户"+username);
        //收支管理
        ImageView btn_recordmanage =findViewById(R.id.btn_recordmanage);
        btn_recordmanage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent1=new Intent(getApplicationContext(), ManageActivity.class);
                startActivity(intent1);
            }
        });
        //收支查询
        ImageView btn_searchrecord=findViewById(R.id.btn_searchrecord);
        btn_searchrecord.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent2=new Intent(getApplicationContext(),SearchRecordActivity.class);
                startActivity(intent2);
            }
        });
        //收支统计
        ImageView btn_calcmoney=findViewById(R.id.btn_calcmoney);
        btn_calcmoney.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent3=new Intent(getApplicationContext(),SearchRecordActivity.class);
                startActivity(intent3);
            }
        });
        //退出按键
        ImageView btn_exit=findViewById(R.id.btn_exit);
        btn_exit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog dialog = new AlertDialog.Builder(UserCenterActivity.this).setTitle("退出操作")
                        .setMessage("确定退出，不继续玩玩？")
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Intent intent=new Intent(getApplicationContext(), MainActivity.class);
                                startActivity(intent);
                            }
                        }).setNegativeButton("继续留下！", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                            }
                        }).create();
                dialog.show();
            }
        });
    }
}
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（5）SearchRecordActivity类

SearchRecordActivity 类是搜索记录页面的Activity，主要编写我的收支页面的业务逻辑。具体代码实现如下：

package com.financial.management;
import androidx.appcompat.app.AppCompatActivity;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
//收支记录页面业务逻辑
public class SearchRecordActivity extends AppCompatActivity {
    //定义spinner中的数据
    private String[] date_data= {"", "202101", "202102", "202103", "202104", "202105","202106","202107","202108","202109","202110","202111","202112"};
    private String[] type_data = {"", "收入", "支出"};
    Spinner spin_date, spin_type;
    ListView listView;
    TextView tv_show;
    float sum=0;
    //数据库
    private String selectDate, selectType;
    private static final String DATABASE_NAME = "Test.db";
    private static final String TABLE_NAME = "record";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_DATE = "date";
    private static final String COLUMN_TYPE = "type";
    private static final String COLUMN_MONEY = "money";
    private static final String COLUMN_STATE = "state";
    private SQLiteDatabase sqLiteDatabase = null;
    private void selectSumMoney() {
        //自定义查询的sql语句
        String sql;
        //如果查询时间和查询类型都为空，则查询整个表
        if (TextUtils.isEmpty(selectDate) && TextUtils.isEmpty(selectType)) {
            sql = "select * from " + TABLE_NAME;
            //如果有查询时间，没有查询类型，查询指定内容
        } else if (!TextUtils.isEmpty(selectDate) && TextUtils.isEmpty(selectType)) {
            sql = "select * from " + TABLE_NAME + " where date='" + selectDate + "'";
            //如果没有查询时间，有查询类型，查询指定内容
        } else if (TextUtils.isEmpty(selectDate) && !TextUtils.isEmpty(selectType)) {//如果没有查询时间，有查询类型
            sql = "select * from " + TABLE_NAME + " where type='" + selectType+"'";
        } else {//否则，查询条件都不为空，查询指定内容
            sql ="select * from " + TABLE_NAME + " where date='" + selectDate + "' and type='" + selectType+"'";
        }
        Cursor cursor = sqLiteDatabase.rawQuery(sql, null);
        while (cursor.moveToNext()) {
            float money = cursor.getFloat(cursor.getColumnIndex(COLUMN_MONEY));
            sum=sum+money;
            //list.add(map);
        }
        String money2=String.valueOf(sum);
        tv_show.setText(money2);
        sum=0;
    }
    //选择数据
    private void selectData() {
        //自定义查询的sql语句
        String sql;
        //如果查询时间和查询类型都为空，则查询整个表
        if (TextUtils.isEmpty(selectDate) && TextUtils.isEmpty(selectType)) {
            sql = "select * from " + TABLE_NAME;
            //如果有查询时间，没有查询类型，查询指定内容
        } else if (!TextUtils.isEmpty(selectDate) && TextUtils.isEmpty(selectType)) {
            sql = "select * from " + TABLE_NAME + " where date='" + selectDate + "'";
            //如果没有查询时间，有查询类型，查询指定内容
        } else if (TextUtils.isEmpty(selectDate) && !TextUtils.isEmpty(selectType)) {//如果没有查询时间，有查询类型
            sql = "select * from " + TABLE_NAME + " where type='" + selectType+"'";
        } else {//否则，查询条件都不为空，查询指定内容
            sql = "select * from " + TABLE_NAME + " where date='" + selectDate + "' and type='" + selectType+"'";
        }
        //将查询到的数据封装到Cursor
        Cursor cursor = sqLiteDatabase.rawQuery(sql, null);
        ArrayList<Map<String, String>> list = new ArrayList<Map<String, String>>();
        if (cursor.getCount() == 0) {
            //查无数据则怒不显示列表
            // listView.setVisibility(View.GONE);
            Toast.makeText(getApplicationContext(), "无数据", Toast.LENGTH_SHORT).show();
        } else {
            //查有数据则显示列表
            listView.setVisibility(View.VISIBLE);
            while (cursor.moveToNext()) {
                int id = cursor.getInt(cursor.getColumnIndex(COLUMN_ID));
                String date = cursor.getString(cursor.getColumnIndex(COLUMN_DATE));
                String type = cursor.getString(cursor.getColumnIndex(COLUMN_TYPE));
                float money = cursor.getFloat(cursor.getColumnIndex(COLUMN_MONEY));
                String state = cursor.getString(cursor.getColumnIndex(COLUMN_STATE));
                Map<String, String> map = new HashMap<String, String>();
                map.put("id", String.valueOf(id));
                map.put("date", date);
                map.put("type", type);
                map.put("money", String.valueOf(money));
                map.put("state", state);
                list.add(map);
            }
            //创建SimpleAdapter
            SimpleAdapter simpleAdapter = new SimpleAdapter(getApplicationContext(),
                    list,
                    R.layout.record_item_layout,
                    new String[]{"id", "date", "type", "money", "state"},
                    new int[]{R.id.list_id, R.id.list_date, R.id.list_type, R.id.list_money, R.id.list_state});
            listView.setAdapter(simpleAdapter);
        }
    }
    //时间和类别spinner点击事件
    private void initClick() {
        //时间事件
        spin_date.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                selectDate = date_data[position];
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
        //类别事件
        spin_type.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                selectType = type_data[position];
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
        findViewById(R.id.btn_search).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                selectData();
            }
        });
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_search_record);
        tv_show=findViewById(R.id.tv_show);
        try {
            //打开数据库，如果是第一次会创建该数据库，模式为MODE_PRIVATE
            sqLiteDatabase = openOrCreateDatabase(DATABASE_NAME, MODE_PRIVATE, null);
            //执行创建表的sql语句，虽然每次都调用，但只有首次才创建表
            //执行查询
            listView = findViewById(R.id.searchlistview);//绑定列表
            selectData();
        } catch (SQLException e) {
            Toast.makeText(this, "数据库异常!", Toast.LENGTH_LONG).show();
            e.printStackTrace();
        }
        ArrayAdapter<String> adapter = new
                ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, date_data);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spin_date = findViewById(R.id.spin_date);
        spin_date.setAdapter(adapter);
        ArrayAdapter<String> adapter1 = new
                ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, type_data);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spin_type = findViewById(R.id.spin_type);
        spin_type.setAdapter(adapter1);
        initClick();
        Button btn_calc=findViewById(R.id.btn_calc);
        btn_calc.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                selectSumMoney();
            }
        });
    }
}
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（6）ManageActivity类

ManageActivity 类是收支管理页面的Activity，主要编写用户的收入和支出的业务逻辑，实现收支的增删改查。具体代码实现如下：

package com.financial.management;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AlertDialog;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
public class ManageActivity extends AppCompatActivity {
    private SQLiteDatabase sqLiteDatabase = null;
    private int selectId = -1;
    EditText edt_date, edt_type, edt_money, edt_state;
    TextView tv_test;
    private static final String DATABASE_NAME = "Test.db";
    private static final String TABLE_NAME = "record";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_DATE = "date";
    private static final String COLUMN_TYPE = "type";
    private static final String COLUMN_MONEY = "money";
    private static final String COLUMN_STATE = "state";
    //创建表
    private static final String CREATE_TABLE = "create table if not exists " + TABLE_NAME
            + "(" + COLUMN_ID + " integer primary key autoincrement," + COLUMN_DATE + " text," + COLUMN_TYPE
            + " text," + COLUMN_MONEY + " float," + COLUMN_STATE + " text)";
    //自定义的查询方法
    private void selectData() {
        //遍历整个表
        String sql = "select * from " + TABLE_NAME ;
        //把查询数据封装到Cursor
        Cursor cursor = sqLiteDatabase.rawQuery(sql, null);
        ArrayList<Map<String, String>> list = new ArrayList<Map<String, String>>();
        //用while循环遍历Cursor，再把它分别放到map中，最后统一存入list中，便于调用
        while (cursor.moveToNext()) {
            int id = cursor.getInt(cursor.getColumnIndex(COLUMN_ID));
            String date = cursor.getString(cursor.getColumnIndex(COLUMN_DATE));
            String type = cursor.getString(cursor.getColumnIndex(COLUMN_TYPE));
            float money = cursor.getFloat(cursor.getColumnIndex(COLUMN_MONEY));
            String state = cursor.getString(cursor.getColumnIndex(COLUMN_STATE));
            Map<String, String> map = new HashMap<String, String>();
            map.put("id", String.valueOf(id));
            map.put("date", date);
            map.put("type", type);
            map.put("money", String.valueOf(money));
            map.put("state", state);
            list.add(map);
        }
        //创建SimpleAdapter
        SimpleAdapter simpleAdapter = new SimpleAdapter(getApplicationContext(),
                list,
                R.layout.record_item_layout,
                new String[]{"id", "date", "type", "money", "state"},
                new int[]{R.id.list_id, R.id.list_date, R.id.list_type, R.id.list_money, R.id.list_state});
        final ListView listView = findViewById(R.id.recordlistview);
        //绑定适配器
        listView.setAdapter(simpleAdapter);
        //设置ListView单击事件
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                ListView tempList = (ListView) parent;
                View mView = tempList.getChildAt(position);
                TextView list_id = mView.findViewById(R.id.list_id);
                TextView list_date = mView.findViewById(R.id.list_date);
                TextView list_type = mView.findViewById(R.id.list_type);
                TextView list_money = mView.findViewById(R.id.list_money);
                TextView list_state = mView.findViewById(R.id.list_state);
                String rid = list_id.getText().toString();
                String date = list_date.getText().toString();
                String type = list_type.getText().toString();
                String money = list_money.getText().toString();
                String state = list_state.getText().toString();
                tv_test.setText(rid);
                edt_date.setText(date);
                edt_type.setText(type);
                edt_money.setText(money);
                edt_state.setText(state);
                selectId = Integer.parseInt(rid);
            }
        });
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_manage);
        try {
            sqLiteDatabase = openOrCreateDatabase(DATABASE_NAME, MODE_PRIVATE, null);
            sqLiteDatabase.execSQL(CREATE_TABLE);
            //执行查询
            selectData();
        } catch (SQLException e) {
            Toast.makeText(this, "数据库异常!", Toast.LENGTH_LONG).show();
            e.printStackTrace();
        }
        tv_test = findViewById(R.id.tv_test);
        edt_date = findViewById(R.id.edt_date);
        edt_type = findViewById(R.id.edt_type);
        edt_money = findViewById(R.id.edt_money);
        edt_state = findViewById(R.id.edt_state);
        //新增按键
        Button btn_add = findViewById(R.id.btn_add);
        btn_add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (edt_date.getText().toString().equals("") | edt_type.getText().toString().equals("") | edt_money.getText().toString().equals("") | edt_state.getText().toString().equals("")) {
                    Toast.makeText(ManageActivity.this, "数据不能为空!", Toast.LENGTH_LONG).show();
                    return;
                }
                String date = edt_date.getText().toString();
                String type = edt_type.getText().toString();
                String money = edt_money.getText().toString();
                String state = edt_state.getText().toString();
                //定义添加数据的sql语句
                String sql = "insert into " + TABLE_NAME + "(" + COLUMN_DATE + "," + COLUMN_TYPE + "," + COLUMN_MONEY + "," + COLUMN_STATE + ") " +
                        "values('" + date + "','" + type + "','" + money + "','" + state + "')";
                //执行sql语句
                sqLiteDatabase.execSQL(sql);
                Toast.makeText(getApplicationContext(), "新增数据成功!", Toast.LENGTH_LONG).show();
                //刷新显示列表
                selectData();
                //消除数据
                tv_test.setText("");
                edt_date.setText("");
                edt_type.setText("");
                edt_money.setText("");
                edt_state.setText("");
            }
        });
        //修改按键
        Button btn_update = findViewById(R.id.btn_update);
        btn_update.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //无选择提示
                if (selectId == -1) {
                    Toast.makeText(getApplicationContext(), "请选择要修改的行!", Toast.LENGTH_LONG).show();
                    return;
                }
                //判断是否有空数据
                if (edt_date.getText().toString().equals("") | edt_type.getText().toString().equals("") | edt_money.getText().toString().equals("") | edt_state.getText().toString().equals("")) {
                    Toast.makeText(getApplicationContext(), "数据不能为空!", Toast.LENGTH_LONG).show();
                    return;
                }
                String date = edt_date.getText().toString();
                String type = edt_type.getText().toString();
                String money = edt_money.getText().toString();
                String state = edt_state.getText().toString();
                //定义修改数据的sql语句
                String sql = "update " + TABLE_NAME + " set " + COLUMN_DATE + "='" + date + "',type='" + type + "',money='" + money + "',state='" + state + "' where id=" + selectId;
                //执行sql语句
                sqLiteDatabase.execSQL(sql);
                Toast.makeText(getApplicationContext(), "修改数据成功!", Toast.LENGTH_LONG).show();
                //刷新显示列表
                selectData();
                selectId = -1;
                //消除数据
                tv_test.setText("");
                edt_date.setText("");
                edt_type.setText("");
                edt_money.setText("");
                edt_state.setText("");
            }
        });
        //删除按键
        Button btn_delete = findViewById(R.id.btn_delete);
        btn_delete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //无选择提示
                if (selectId == -1) {
                    Toast.makeText(ManageActivity.this, "请选择要删除的行!", Toast.LENGTH_LONG).show();
                    return;
                }
                //定义删除对话框
                AlertDialog dialog = new AlertDialog.Builder(ManageActivity.this).setTitle("删除操作")
                        .setMessage("确定删除？此操作不可逆，请慎重选择！")
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                //定义删除的sql语句
                                String sql = "delete from " + TABLE_NAME + " where id=" + selectId;
                                //执行sql语句
                                sqLiteDatabase.execSQL(sql);
                                //刷新显示列表
                                Toast.makeText(getApplicationContext(), "删除数据成功!", Toast.LENGTH_LONG).show();
                                selectData();
                                selectId = -1;
                                //清除数据
                                tv_test.setText("");
                                edt_date.setText("");
                                edt_type.setText("");
                                edt_money.setText("");
                                edt_state.setText("");
                            }
                        }).setNegativeButton("取消", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                            }
                        }).create();
                dialog.show();
            }
        });
    }
}
复制代码

（7）User类

User 类是用户类Activity，用于获取用户ID以及密码。具体代码实现如下：

package com.financial.management;
import android.os.Parcel;
import android.os.Parcelable;
public class User implements Parcelable {
    private String userId="";
    private String userPwd="";
    public String getUserId() {
        return userId;
    }
    public void setUserId(String userId) {
        this.userId = userId;
    }
    public String getUserPwd() {
        return userPwd;
    }
    public void setUserPwd(String userPwd) {
        this.userPwd = userPwd;
    }
    @Override
    public int describeContents() {
        return 0;
    }
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(this.userId);
        dest.writeString(this.userPwd);
    }
    public User() {
    }
    protected User(Parcel in) {
        this.userId = in.readString();
        this.userPwd = in.readString();
    }
    public static final Creator<User> CREATOR = new Creator<User>() {
        @Override
        public User createFromParcel(Parcel source) {
            return new User(source);
        }
        @Override
        public User[] newArray(int size) {
            return new User[size];
        }
    };
}
复制代码

🎵三、运行结果Result

到这里，整个系统的设计就差不多要结束啦！现在我们用一段视频来演示整个系统的运行效果🌈

如想看BGM版本，可点击此链接进入观看~

📈四、结束语

在拿到这个课题呢，周一首先对课题进行了系统结构设计，结构设计完成之后就到了编码阶段。编码阶段分为两部分进行，先是进行静态页面的楷模，而后到了业务逻辑的编写。

讲到这里，整个系统从设计阶段到编码阶段的整个过程讲解就结束啦！这也算是我学习Android的第一个小作品，作品不完美之处较多，后续还将会继续改进~

10分钟手把手教你用Android手撸一个简易的个人记账App（二）

（6）列表数据记录record_item_layout.xml

3. 逻辑结构💡

（1）DBHelper类

（2）MainActivity类

（3）RegisterActivity类

（4）UserCenterActivity类

（5）SearchRecordActivity类

（6）ManageActivity类

（7）User类

🎵三、运行结果Result

📈四、结束语

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10分钟手把手教你用Android手撸一个简易的个人记账App（二）

（6）列表数据记录record_item_layout.xml

3. 逻辑结构💡

（1）DBHelper类

（2）MainActivity类

（3）RegisterActivity类

（4）UserCenterActivity类

（5）SearchRecordActivity类

（6）ManageActivity类

（7）User类

🎵三、运行结果Result

📈四、结束语

热门文章

最新文章

相关课程

相关电子书

相关实验场景