（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> 复制代码
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); } } 复制代码
（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); } }); } } 复制代码
（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(); } } }); } } 复制代码
（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(); } }); } } 复制代码
（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(); } }); } } 复制代码
（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~
