项目要求：1.三类角色，分别为提问者（学生）、回答者（教师）、潜水者（游客），子类(学生Student、教师Teacher)、父类(Person)；
2.根据不同角色增加接口，每个角色一个（教师：回答接口Answerer, 学生：提问接口Questioner, 游客：公共接口Common）；
3.任何人可以点“赞”，可以评论（公共接口Common）；
4.教师类可以为回答打分（接口Answerer）、提问者可以为回答打分（接口Questioner）；
5.必须用数据库（如SQLite）存储信息；//目前用户信息表已完成，问题及其相关信息(包括问题内容，提问者；该问题对应的回答（最多3个）及其回答者、点赞数等）待完善
6.重点代码注释；
请你帮我完善代码，在main页面显示问题列表
package com.example.iask0;
import android.content.Intent;
import android.view.View;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import com.example.iask0.databinding.ActivityMainBinding;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.ListView;
import android.widget.Toast;
import java.util.List;
import db.DatabaseManager;
import db.Question;
import db.QuestionAdapter;
public class MainActivity extends AppCompatActivity {
public TextView identityTextView;
public EditText searchEditText;
public Button searchButton;
private Button askButton;
private Button mineButton;
private DatabaseManager dbManager;
public ListView questionListView; // 问题列表视图
public List<Question> questionList; // 问题数据列表
private QuestionAdapter adapter; // 问题列表适配器
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
identityTextView = findViewById(R.id.identityTextView);
searchEditText = findViewById(R.id.searchEditText);
searchButton = findViewById(R.id.searchButton);
askButton = findViewById(R.id.askButton);
mineButton=findViewById(R.id.mineButton);
questionListView=findViewById(R.id.questionListView);
//questionListView=findViewById(R.layout.item_question);
dbManager = new DatabaseManager(this);
dbManager.open();
//获取传递的信息
Intent intent = getIntent();
String username = intent.getStringExtra("username");
String identity= getCurrentIdentity();
identityTextView.setText("身份：" + identity);// 设置用户身份
// 搜索按钮点击事件
searchButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String query = searchEditText.getText().toString();
if (!query.isEmpty()) {
// 执行搜索操作
Toast.makeText(MainActivity.this, "搜索: " + query, Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "请输入搜索内容", Toast.LENGTH_SHORT).show();
}
}
});
// 提问按钮点击事件（仅学生可按）
askButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 执行提问操作
String question = searchEditText.getText().toString();
if(dbManager.insertQuestion(question, username)!=-1) {
Toast.makeText(MainActivity.this, "问题提交成功", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(MainActivity.this, QuestionDetailActivity.class);
intent.putExtra("username_asker", username);
intent.putExtra("username", username);
intent.putExtra("identity", getCurrentIdentity());
intent.putExtra("question_content", question);
startActivity(intent);
finish();
}
else{
Toast.makeText(MainActivity.this, "故障！问题提交失败", Toast.LENGTH_SHORT).show();
}
}
});
//“我的”按钮
mineButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, MyActivity.class);
intent.putExtra("username", username);
intent.putExtra("identity", getCurrentIdentity());
startActivity(intent);
}
});
toggleAskButtonVisibility();// 根据当前用户身份显示或隐藏提问按钮
loadQuestionsList(); //加载问题列表
}
private String getCurrentIdentity() {
// 从Intent获取登录信息
Intent intent = getIntent();
String identity = intent.getStringExtra("identity");
// 设置身份
if (identity == null) {
identity = "游客";
}
return identity;
}
private void toggleAskButtonVisibility() {
String identity = getCurrentIdentity();
if ("学生".equals(identity)) {
askButton.setVisibility(View.VISIBLE);
} else {
askButton.setVisibility(View.GONE);
}
}
private void loadQuestionsList() {
questionList = dbManager.getAllQuestions();// 从数据库获取所有问题
// 创建并设置适配器
adapter = new QuestionAdapter(this, questionList);
questionListView.setAdapter(adapter);
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- 顶部区域 -->
<LinearLayout
android:id="@+id/topBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:background="#5F8772"
android:padding="16dp">
<!-- 标题 -->
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_marginLeft="64dp"
android:gravity="center"
android:text="iask 主页"
android:textColor="#FFFFFF"
android:textSize="25sp"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center">
<!-- 用户身份 -->
<TextView
android:id="@+id/identityTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="身份：游客"
android:textColor="#FFFFFF"/>
<!--个人界面跳转按钮-->
<Button
android:id="@+id/mineButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="我的"
android:background="#303030"/>
</LinearLayout>
</LinearLayout>
<!-- 搜索区域 -->
<LinearLayout android:id="@+id/searchBar"
android:layout_below="@id/topBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="8dp">
<!-- 输入框 -->
<EditText
android:id="@+id/searchEditText"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="输入搜索内容"
android:padding="28dp"
android:background="#FFFFFF"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<!-- 搜索按钮 -->
<Button
android:id="@+id/searchButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="搜索"
android:background="#303030"/>
<!-- 提问按钮（仅学生可按） -->
<Button
android:id="@+id/askButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="提问"
android:background="#000000"
android:visibility="gone"/> <!-- 默认不显示 -->
</LinearLayout>
</LinearLayout>
<!-- 问题区域 -->
<LinearLayout
android:id="@+id/questionBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/searchBar"
android:orientation="vertical">
<!-- 选项卡 -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:id="@+id/questionsListHeading">
<TextView
android:id="@+id/tabQuestions"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="问题（时间倒序）"
android:gravity="center"
android:padding="8dp"
android:background="#FAFAFA"/>
<TextView
android:id="@+id/tabAnswers"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0"
android:text="回答数"
android:gravity="center"
android:padding="8dp"
android:background="#FAFAFA"/>
</LinearLayout>
<!-- 问题列表项 -->
<ListView
android:id="@+id/questionListView"
android:layout_below="@+id/questionsListHeading"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
<!--
<LinearLayout
android:id="@+id/bottomBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/questionBar">
<Button
android:id="@+id/homeButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="我的"
android:background="#303030"/>
</LinearLayout>-->
</RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<!-- 问题内容 -->
<TextView
android:id="@+id/questionContent"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="16sp"
android:textColor="#333333"
android:maxLines="2"
android:ellipsize="end"/>
<!-- 问题元信息（问题和回答数） -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="5dp">
<TextView
android:id="@+id/questionTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12sp"
android:textColor="#666666"/>
<TextView
android:id="@+id/answerCount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12sp"
android:textColor="#666666"
android:layout_marginStart="15dp"/>
</LinearLayout>
</RelativeLayout>
package com.example.iask0;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import db.DatabaseManager;
public class QuestionDetailActivity extends AppCompatActivity {
private TextView identityTextView;
public TextView questionTextView;
public TextView askerView;
private EditText answerEditText;
private Button submitAnswerButton;
private ListView answerListView;
private DatabaseManager dbManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_question_detail);
identityTextView = findViewById(R.id.identityTextView);
questionTextView =findViewById(R.id.questionText);
askerView = findViewById(R.id.asker);
answerEditText = findViewById(R.id.answerEditText);
submitAnswerButton = findViewById(R.id.submitAnswerButton);
answerListView = findViewById(R.id.answerListView);
Button backButton = findViewById(R.id.backButton);
Intent intent = getIntent();
String username = intent.getStringExtra("username");
String askername = intent.getStringExtra("username_asker");
String identity = intent.getStringExtra("identity");
String question = intent.getStringExtra("question_content");
// 设置身份和用户名
if (username != null && identity != null) {
setIdentity(identity);
} else {
setIdentity("游客");
}
questionTextView.setText("问题内容\n" + question);
askerView.setText("提问者："+ askername);
backButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(QuestionDetailActivity.this, MainActivity.class);
intent.putExtra("username", username);
intent.putExtra("identity", identity);
startActivity(intent);
finish();
}
});
submitAnswerButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String answer = answerEditText.getText().toString();
// 提交回答逻辑
EditText answerContentEditText = findViewById(R.id.answerEditText);
String answerContent = answerContentEditText.getText().toString();
String responder = username;
long questionId = 1; // 示例问题ID，实际应用中应动态获取
long answerId = dbManager.insertAnswer(answerContent, responder, questionId);
if (answerId != -1) {
Toast.makeText(QuestionDetailActivity.this, "回答提交成功", Toast.LENGTH_SHORT).show();
}
}
});
}
//界面显示 根据身份
private void setIdentity(String identity) {
identityTextView.setText("身份：" + identity);
identityTextView.setVisibility(View.VISIBLE);
if ("教师".equals(identity)) {
answerEditText.setVisibility(View.VISIBLE);
submitAnswerButton.setVisibility(View.VISIBLE);
} else {
answerEditText.setVisibility(View.GONE);
submitAnswerButton.setVisibility(View.GONE);
}
}
}
package db;
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;
import android.icu.text.SimpleDateFormat;
import android.util.Log;
import java.text.ParseException;
import java.util.*;
public class DatabaseManager extends SQLiteOpenHelper{
private SQLiteDatabase database;
private static final String DATABASE_NAME = "iAsk.db";
private static final int DATABASE_VERSION = 1; // 数据库版本
//user表
public static final String TABLE_NAME = "userss";// 表名
// 列名
public static final String COLUMN_ID = "id";
public static final String COLUMN_NAME = "username";
public static final String COLUMN_PASSWORD = "password";
public static final String COLUMN_IDENTIFY = "identity";
//问题和回答表
public static final String QUESTIONS_TABLE_NAME = "questions";
public static final String ANSWERS_TABLE_NAME = "answers";
public static final String QUESTION_ID = "question_id";
public static final String QUESTION_CONTENT = "question_content";
public static final String QUESTION_ASKER = "question_asker";
public static final String QUESTION_TIMESTAMP = "question_timestamp";
public static final String ANSWER_ID = "answer_id";
public static final String ANSWER_CONTENT = "answer_content";
public static final String ANSWER_RESPONDER = "answer_responder";
public static final String ANSWER_TIMESTAMP = "answer_timestamp";
public static final String ANSWER_LIKES = "answer_likes";
public static final String ANSWER_QUESTION_ID = "answer_question_id";
public DatabaseManager(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
Log.d("DB_DEBUG", "===== 进入 DB =====");
this.getWritableDatabase();
}
// 创建表的SQL语句
private static final String TABLE_CREATE = "CREATE TABLE IF NOT EXISTS " + TABLE_NAME +
" (" + "id INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_NAME + " TEXT NOT NULL, " +
COLUMN_PASSWORD + " TEXT NOT NULL, "+
COLUMN_IDENTIFY + " TEXT NOT NULL);";//用户表
private static final String CREATE_QUESTIONS_TABLE =
"CREATE TABLE IF NOT EXISTS " + QUESTIONS_TABLE_NAME + " (" +
QUESTION_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
QUESTION_CONTENT + " TEXT NOT NULL, " +
QUESTION_ASKER + " TEXT NOT NULL, " +
QUESTION_TIMESTAMP + " TIMESTAMP DEFAULT CURRENT_TIMESTAMP" +
");";//问题表
private static final String CREATE_ANSWERS_TABLE =
"CREATE TABLE IF NOT EXISTS " + ANSWERS_TABLE_NAME + " (" +
ANSWER_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
ANSWER_CONTENT + " TEXT NOT NULL, " +
ANSWER_RESPONDER + " TEXT NOT NULL, " +
ANSWER_TIMESTAMP + " TIMESTAMP DEFAULT CURRENT_TIMESTAMP, " +
ANSWER_LIKES + " INTEGER DEFAULT 0, " +
ANSWER_QUESTION_ID + " INTEGER NOT NULL, " +
"teacher_score REAL DEFAULT 0, " + // 教师评分
"student_score REAL DEFAULT 0, " + // 学生评分
"FOREIGN KEY (" + ANSWER_QUESTION_ID + ") REFERENCES " + QUESTIONS_TABLE_NAME + "(" + QUESTION_ID + ")" +
");";//回答表
@Override
public void onCreate(SQLiteDatabase db) {
Log.d("DB_DEBUG", " ====== 创 建 表 ====== ");
// 创建表
db.execSQL(TABLE_CREATE);
db.execSQL(CREATE_QUESTIONS_TABLE);
db.execSQL(CREATE_ANSWERS_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {//数据库版本更新
// 删除旧表，创建新表（但会丢失数据）
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
db.execSQL("DROP TABLE IF EXISTS " + QUESTIONS_TABLE_NAME);
db.execSQL("DROP TABLE IF EXISTS " + ANSWERS_TABLE_NAME);
onCreate(db);
}
// 打开数据库
public void open() {
database=this.getWritableDatabase();
}
// 检查用户名是否存在（查找数据-user）
public boolean checkUsernameExists(String username) {
SQLiteDatabase database = this.getReadableDatabase();
Cursor cursor = database.query(TABLE_NAME, new String[]{COLUMN_NAME}, COLUMN_NAME + "=?", new String[]{username}, null, null, null);
boolean exists = cursor.getCount() > 0;
cursor.close();
return exists;
}
// 注册（插入数据-user）
public boolean insertUser(String username, String password, String identity) {
SQLiteDatabase database = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(COLUMN_NAME, username);
values.put(COLUMN_PASSWORD, password);
values.put(COLUMN_IDENTIFY, identity);
long result = database.insert(TABLE_NAME, null, values);
return result != -1;
}
//登录（查找数据-user）
public boolean checkPassword(String username, String password) {
SQLiteDatabase readableDatabase = this.getReadableDatabase();
Cursor cursor = readableDatabase.query(//在TABLE_NAME表查询 用户名为 username 的密码
TABLE_NAME,
new String[]{COLUMN_PASSWORD},
COLUMN_NAME + " = ?",
new String[]{username},
null, null, null
);
boolean isPasswordCorrect = false;
if (cursor.moveToFirst()) {
int columnIndex = cursor.getColumnIndex(COLUMN_PASSWORD); // 获取密码列的索引
if (columnIndex != -1) {
String storedPassword = cursor.getString(columnIndex); // 获取存储的密码
isPasswordCorrect = storedPassword.equals(password); //判断密码是否正确
} else {
Log.e("DB_DEBUG", "COLUMN_PASSWORD column not found in the table.");
}
}
cursor.close();
return isPasswordCorrect;
}
//获取身份（查找数据-user）
public String getIdentity(String username) {
SQLiteDatabase readableDatabase = this.getReadableDatabase();
Cursor cursor = readableDatabase.query(
TABLE_NAME,
new String[]{COLUMN_IDENTIFY},
COLUMN_NAME + " = ?",
new String[]{username},
null, null, null
);
String identity = "";
if (cursor.moveToFirst()) {
int columnIndex = cursor.getColumnIndex(COLUMN_IDENTIFY);
if (columnIndex != -1) {
identity = cursor.getString(columnIndex);
}
}
cursor.close();
return identity;
}
//插入数据（提问和回答-question&answer）
public long insertQuestion(String content, String asker) {
database= this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(QUESTION_CONTENT, content);
values.put(QUESTION_ASKER, asker);
return database.insert(QUESTIONS_TABLE_NAME, null, values);
}
public long insertAnswer(String content, String responder, long questionId) {
database= this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(ANSWER_CONTENT, content);
values.put(ANSWER_RESPONDER, responder);
values.put(ANSWER_QUESTION_ID, questionId);
return database.insert(ANSWERS_TABLE_NAME, null, values);
}
//查找所有问题
public List<Question> getAllQuestions() {
List<Question> questions = new ArrayList<>();
database = this.getReadableDatabase();
// 查询问题并按时间倒序排列
String query = "SELECT q.*, COUNT(a.answer_id) as answer_count " +
"FROM " + QUESTIONS_TABLE_NAME + " q " +
"LEFT JOIN " + ANSWERS_TABLE_NAME + " a ON q.question_id = a.answer_question_id " +
"GROUP BY q.question_id " +
"ORDER BY q.question_timestamp DESC";
Cursor cursor = database.rawQuery(query, null);
if (cursor.moveToFirst()) {
do {
int id = cursor.getInt(cursor.getColumnIndexOrThrow(QUESTION_ID));
String content = cursor.getString(cursor.getColumnIndexOrThrow(QUESTION_CONTENT));
String asker = cursor.getString(cursor.getColumnIndexOrThrow(QUESTION_ASKER));
String timestampStr = cursor.getString(cursor.getColumnIndexOrThrow(QUESTION_TIMESTAMP));
int answerCount = cursor.getInt(cursor.getColumnIndexOrThrow("answer_count"));
// 转换时间戳字符串为Date对象
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.getDefault());
Date timestamp = null;
try {
timestamp = sdf.parse(timestampStr);
} catch (ParseException e) {
throw new RuntimeException(e);
}
questions.add(new Question(id, content, asker, timestamp, answerCount));
} while (cursor.moveToNext());
}
cursor.close();
return questions;
}
//查找问题id
public ContentValues getQuestionById(long questionId) {
SQLiteDatabase readableDatabase = this.getReadableDatabase();
Cursor cursor = readableDatabase.query(
QUESTIONS_TABLE_NAME,
new String[]{QUESTION_ID, QUESTION_CONTENT, QUESTION_ASKER, QUESTION_TIMESTAMP},
QUESTION_ID + " = ?",
new String[]{String.valueOf(questionId)},
null, null, null
);
ContentValues question = null;
if (cursor.moveToFirst()) {
long id = cursor.getLong(cursor.getColumnIndexOrThrow(QUESTION_ID));
int idIndex = cursor.getColumnIndex(QUESTION_ID);
int contentIndex = cursor.getColumnIndex(QUESTION_CONTENT);
int askerIndex = cursor.getColumnIndex(QUESTION_ASKER);
int timestampIndex = cursor.getColumnIndex(QUESTION_TIMESTAMP);
int answerCount = getAnswerCount(id);
if (idIndex != -1 && contentIndex != -1 && askerIndex != -1 && timestampIndex != -1) {
question = new ContentValues();
question.put(QUESTION_ID, cursor.getLong(idIndex));
question.put(QUESTION_CONTENT, cursor.getString(contentIndex));
question.put(QUESTION_ASKER, cursor.getString(askerIndex));
question.put(QUESTION_TIMESTAMP, cursor.getString(timestampIndex));
} else {
Log.e("DB_DEBUG", "Missing columns in questions table.");
}
}
cursor.close();
return question;
}
//搜索问题 根据关键词
public List<Question> searchQuestions(String keyword) {
List<Question> questionList = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(QUESTIONS_TABLE_NAME, null, QUESTION_CONTENT + " LIKE ?", new String[]{"%" + keyword + "%"}, null, null, QUESTION_TIMESTAMP + " DESC");
if (cursor != null && cursor.moveToFirst()) {
do {
long id = cursor.getLong(cursor.getColumnIndexOrThrow(QUESTION_ID));
String content = cursor.getString(cursor.getColumnIndexOrThrow(QUESTION_CONTENT));
String asker = cursor.getString(cursor.getColumnIndexOrThrow(QUESTION_ASKER));
String timestampStr = cursor.getString(cursor.getColumnIndexOrThrow(QUESTION_TIMESTAMP));
int answerCount = getAnswerCount(id);
// 转换时间戳字符串为Date对象
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.getDefault());
Date timestamp = null;
try {
timestamp = sdf.parse(timestampStr);
} catch (ParseException e) {
throw new RuntimeException(e);
}
questionList.add(new Question(id, content, asker, timestamp, answerCount));
} while (cursor.moveToNext());
}
if (cursor != null) {
cursor.close();
}
return questionList;
}
public int getAnswerCount(long questionId) {
database= this.getReadableDatabase();
Cursor cursor = database.query(ANSWERS_TABLE_NAME, null, ANSWER_QUESTION_ID + " = ?", new String[]{String.valueOf(questionId)}, null, null, null);
int count = cursor.getCount();
cursor.close();
return count;
}
//查找与更新数据（点赞-answer)
public void updateAnswerLikes(long answerId, int likes) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(ANSWER_LIKES, likes);
db.update(ANSWERS_TABLE_NAME, values, ANSWER_ID + " = ?", new String[]{String.valueOf(answerId)});
}
//评分
public boolean updateTeacherScore(long answerId, float score) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("teacher_score", score);
return db.update(ANSWERS_TABLE_NAME, values,
ANSWER_ID + " = ?",
new String[]{String.valueOf(answerId)}) > 0;
}
// 更新数据
public int updateItem(long id, String username, String identify) {
ContentValues values = new ContentValues();
values.put(COLUMN_NAME, username);
values.put(COLUMN_IDENTIFY, identify);
return database.update(
TABLE_NAME,
values,
COLUMN_ID + " = ?",
new String[]{String.valueOf(id)}
);
}
}
---
package db;
public interface Common {
void comment();//评论
void like();//点赞
}
---
package db;
public interface Questioner {
void ask();//提问
void score();//评分
}
---
package db;
public class Person implements Common{
private long id;
private String username;
private String password;
private String identify;
public Person(long id, String username, String password, String identify) {
this.id = id;
this.username = username;
this.password = password;
this.identify=identify;
}}
--
package db;
public class Student extends Person implements Questioner{
public Student(long id, String username, String password, String identify,String question) {
super(id, username, password, identify);
}
@Override
public void like(){//点赞
}
@Override
public void comment(){//评论
}
@Override
public void ask() {//提问
}
@Override
public void score() {//评分
}
}
--
package db;
import java.util.Date;
public class Question {
private long id;
private String content;
private String asker;
private Date timestamp;
private int answerCount;
public Question(long id, String content, String asker, Date timestamp, int answerCount) {
this.id = id;
this.content = content;
this.asker = asker;
this.timestamp = timestamp;
this.answerCount = answerCount;
}
// Getters and Setters
public long getId() { return id; }
public String getContent() { return content; }
public String getAsker() { return asker; }
public Date getTimestamp() { return timestamp; }
public int getAnswerCount() { return answerCount; }
}
已完成部分，用于参考：
package com.example.iask0;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import db.*;
public class RegisterActivity extends AppCompatActivity {
private EditText usernameEditText;
private EditText passwordEditText;
private EditText confirmPasswordEditText;
private TextView usernameTakenTextView;
private TextView passwordMismatchTextView;
private RadioButton teacherRadioButton;
private RadioButton studentRadioButton;
private Button registerButton;
private Button backloginButton;
private DatabaseManager dbManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
usernameEditText = findViewById(R.id.usernameEditText);
passwordEditText = findViewById(R.id.passwordEditText);
confirmPasswordEditText = findViewById(R.id.confirmPasswordEditText);
usernameTakenTextView = findViewById(R.id.usernameTakenTextView);
passwordMismatchTextView = findViewById(R.id.passwordMismatchTextView);
RadioGroup identityRadioGroup = findViewById(R.id.identityRadioGroup);
teacherRadioButton = findViewById(R.id.teacherRadioButton);
studentRadioButton = findViewById(R.id.studentRadioButton);
registerButton = findViewById(R.id.registerButton);
backloginButton=findViewById(R.id.backLoginButton);
dbManager = new DatabaseManager(this);
dbManager.open();
registerButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
attemptRegistration();}
});
backloginButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 返回登录界面
Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);
startActivity(intent);
finish();
}
});
}
private void attemptRegistration() {
String username = usernameEditText.getText().toString();
String password = passwordEditText.getText().toString();
String confirmPassword = confirmPasswordEditText.getText().toString();
//int selectedId = identityRadioGroup.getCheckedRadioButtonId();
if (username.isEmpty()) {//用户名为空提示
Toast.makeText(RegisterActivity.this, "请输入用户名", Toast.LENGTH_SHORT).show();
return;
}
if (password.isEmpty() || confirmPassword.isEmpty()) {//密码为空提示
Toast.makeText(RegisterActivity.this, "请输入密码", Toast.LENGTH_SHORT).show();
return;
}
if (!password.equals(confirmPassword)) {//确认密码与密码不同提示
passwordMismatchTextView.setVisibility(View.VISIBLE);
return;
} else {
passwordMismatchTextView.setVisibility(View.GONE);
}
// 获取选中的身份
//String tableName;
String identity;
if (teacherRadioButton.isChecked()) {
identity = "教师";
//tableName = "tch";
}
else if (studentRadioButton.isChecked()) {
identity = "学生";
//tableName = "stu";
}
else {
Toast.makeText(RegisterActivity.this, "请选择身份", Toast.LENGTH_SHORT).show();
return;
}
// 检查用户名是否被占用，注册
if (dbManager.checkUsernameExists(username)) {
usernameTakenTextView.setVisibility(View.VISIBLE);
}
else {
usernameTakenTextView.setVisibility(View.GONE);
if (dbManager.insertUser(username, password, identity)) {
Toast.makeText(RegisterActivity.this, "注册成功", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(RegisterActivity.this, "注册失败", Toast.LENGTH_SHORT).show();
}
}
}
@Override
protected void onDestroy() {
super.onDestroy();
dbManager.close();
}
}
本文介绍了一种简单的方法来禁用ASP.NET MVC中的输入验证，通过在后台表单接收处添加特性[ValidateInput(false)]，可以有效地解决因输入验证导致的问题。
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