Android答题APP的设计与实现

//****连接数据库**DBManager***
public class DBManager {

 // 数据库连接常量
 public static final String DRIVER = "com.mysql.jdbc.Driver";
 public static final String USER = "root";
 public static final String PASS = "root";
 public static final String URL = "jdbc:mysql://localhost:3306/shop";

 // 静态成员，支持单态模式
 private static DBManager per = null;
 private Connection conn = null;
 private Statement stmt = null;

 // 单态模式-懒汉模式
 private DBManager() {
 }

 public static DBManager createInstance() {
  if (per == null) {
   per = new DBManager();
   per.initDB();
  }
  return per;
 }

 // 加载驱动
 public void initDB() {
  try {
   Class.forName("com.mysql.jdbc.Driver");
  } catch (Exception e) {
   e.printStackTrace();
  }
 }

 // 连接数据库，获取句柄+对象
 public void connectDB() {
  System.out.println("Connecting to database...");
  try {
   conn = DriverManager.getConnection(URL,USER,PASS);
   stmt = conn.createStatement();
  } catch (SQLException e) {
   e.printStackTrace();
  }
  System.out.println("SqlManager:Connect to database successful.");
 }

 // 关闭数据库 关闭对象，释放句柄
 public void closeDB() {
  System.out.println("Close connection to database..");
  try {
   stmt.close();
   conn.close();
  } catch (SQLException e) {
   e.printStackTrace();
  }
  System.out.println("Close connection successful");
 }

 // 查询
 public ResultSet executeQuery(String sql) {
  ResultSet rs = null;
  try {
   rs = stmt.executeQuery(sql);
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return rs;
 }

 // 增添/删除/修改
 public int executeUpdate(String sql) {
  int ret = 0;
  try {
   ret = stmt.executeUpdate(sql);
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return ret;
 }
}

//****服务代码****
public class StartService {
 /**
  * 登录方法
  * @param username
  * @param password
  * @return 登录成功与否
  */
 public HashMap<String,String> login(String username,String password) {

  HashMap<String,String> hashMap = new HashMap<String,String>();
  // 获取Sql查询语句
  String logSql = "select perssion from userinfo where username ='"
    + username + "' and password ='" + password + "'";
  System.out.println(logSql);
  // 获取DB对象
  DBManager sql = DBManager.createInstance();
  sql.connectDB();

  hashMap.put("permission","-1");
  hashMap.put("username",username);

  // 操作DB对象
  try {
   ResultSet rs = sql.executeQuery(logSql);
   if (rs.next()) {
    hashMap.put("permission",rs.getInt(1) + "");
    System.out.print("权限===" + rs.getInt(1) + "t");
    sql.closeDB();
    return hashMap;
   }
  } catch (SQLException e) {
   e.printStackTrace();
  }
  sql.closeDB();
  return hashMap;
 }

 /**
  * 注册方法
  * @param username
  * @param password
  * @return 注册成功与否
  */
 public HashMap<String,String> register(String username,String>();
  hashMap.put("username",username);
  hashMap.put("msg","notok");
  if (this.namerepeat(username)) {
   hashMap.put("msg","rename");
  } else {
   // 获取Sql查询语句
   String regSql = "insert into userinfo(username,password) values('"
     + username + "','" + password + "')";
   System.out.println(regSql);

   // 获取DB对象
   DBManager sql = DBManager.createInstance();
   sql.connectDB();

   int ret = sql.executeUpdate(regSql);
   if (ret != 0) {
    hashMap.put("msg","ok");
    sql.closeDB();
    return hashMap;
   }
   sql.closeDB();
  }

  return hashMap;
 }

 /**
  * 检测该账户是否已经注册
  * 
  * @param username
  * @return 注册状态
  */
 public Boolean namerepeat(String username) {
  String checkSql = "select username from userinfo where username ='"
    + username + "'";
  // 获取Sql查询语句
  System.out.println(checkSql);

  // 获取DB对象
  DBManager sql = DBManager.createInstance();
  sql.connectDB();

  // 操作DB对象
  try {
   ResultSet rs = sql.executeQuery(checkSql);
   if (rs.next()) {

    sql.closeDB();
    return true;
   }
  } catch (SQLException e) {
   e.printStackTrace();
  }
  sql.closeDB();
  return false;
 }
}

//****登录代码****
String username = request.getParameter("username");
String password = request.getParameter("password");
username = new String(username.getBytes("ISO-8859-1"),"UTF-8");
System.out.println("客户端参数：" + username + " ====== " + password);
 // 新建服务对象，默认权限为-1（未登录状态）
 StartService serv = new StartService();
 int permission = -1;
 HashMap<String,String> logiii = serv.login(username,password);
 String a = logiii.get("username");
 // 登陆验证处理（权限>-1为登录成功）
 if ("-1".equals(logiii.get("permission"))) {
  // 登录失败
  System.out.print("登录失败Failed");
 } else {
  // 登陆成功
  permission = Integer.parseInt(logiii.get("permission"));
 }
 JSONObject jsonObj = new JSONObject();
 try {
  jsonObj.put("username",username);
  jsonObj.put("permission",permission);
  System.out.println(jsonObj);
  // 返回信息到客户端
  response.setCharacterEncoding("UTF-8");
  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  out.print(jsonObj);
  out.flush();
  out.close();
 } catch (JSONException e) {
  e.printStackTrace();
 }

{
 "username": "001","msg": "ok"
}

{
 "username": "001","permission": 0
}

{
 "status": ok,//连接状态
 "code": "200" //错误代码
 "messages": [ //题目内容
  {
   "_id": 1,//题目id
   "title": "1+1=？" //题目
   "q_type": 0,//题目类型
   "optionA": "1",//A选项
   "optionB": "2",//B选项
   "optionC": "3",//C选项
   "optionD": "4",//D选项
   "tips”:"这么简单还要提示？",//提示
   "answer": "B",//答案
  },{
   "_id": 2,"title": "2+2=?" 
   "q_type": 0,"optionA": "1","optionB": "2","optionC": "3","optionD": "4","tips":"这么简单还要提示？","answer": "D",}
 ],}

public abstract class BaseActivity extends FragmentActivity implements View.OnClickListener {
 @Override
 protected final void onCreate(@Nullable Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  //得到布局文件
  setContentView(getLayoutId());

  //初始化
  initView();
  initData();
  initListener();
 }

 /**
  * @return 布局文件id
  */
 abstract int getLayoutId();

 /**
  * 初始化View
  */
 void initView() {
 }

 /**
  * 初始化界面数据
  */
 void initData() {
 }

 /**
  * 绑定监听器与适配器
  */
 void initListener() {
 }

 /**
  * 对统一的按钮进行统一处理
  *
  * @param v 点击的View
  */
 @Override
 public void onClick(View v) {
  switch (v.getId()) {
   default:
    processClick(v);
    break;
  }
 }

 /**
  * 点击事件
  *
  * @param v 点击的View
  */
 void processClick(View v) {
 }
}

public class SplashActivity extends BaseActivity {

 @Override
 int getLayoutId() {
  return R.layout.activity_splash;
 }
 @Override
 void initData() {
  //延时2s，跳转。
  new Handler().postDelayed(new Runnable() {
   @Override
   public void run() {
    //跳转主页面
    Intent intent = new Intent(SplashActivity.this,MainActivity.class);
    startActivity(intent);
    finish();
   }
  },2000);
 }

}

public class LoginActivity extends BaseActivity {
 private static final int REQUEST_SIGNUP = 0;
 EditText et_username;
 EditText et_password;
 Button btn_login;
 TextView tv_signup;

 @Override
 int getLayoutId() {
  return R.layout.activity_login;
 }

 @Override
 void initView() {
  //通过id找控件
  et_username = (EditText) findViewById(R.id.input_username);
  et_password = (EditText) findViewById(R.id.input_password);
  btn_login = (Button) findViewById(R.id.btn_login);
  tv_signup = (TextView) findViewById(R.id.link_signup);
 }

 @Override
 void initListener() {
  //登录按钮，注册链接设置点击监听事件
  btn_login.setOnClickListener(this);
  tv_signup.setOnClickListener(this);
 }

 @Override
 void processClick(View v) {
  switch (v.getId()) {
   //点击登录按钮，执行登录操作
   case R.id.btn_login:
    login();
    break;
   //如果点击了注册链接，则跳转到注册页面
   case R.id.link_signup:
    Intent intent = new Intent(getApplicationContext(),SignupActivity.class);
    startActivityForResult(intent,REQUEST_SIGNUP);
    finish();
    //动画效果
    overridePendingTransition(R.anim.push_left_in,R.anim.push_left_out);
    break;
   default:
    break;
  }
 }

 /**
  * 登录方法
  */
 public void login() {
  //如果内容不合法，则直接返回，显示错误。
  if (!validate()) {
   onLoginFailed();
   return;
  }
  //输入合法，将登录按钮置为不可用，显示圆形进度对话框
  btn_login.setEnabled(false);
  final ProgressDialog progressDialog = new ProgressDialog(LoginActivity.this,R.style.AppTheme_Dark_Dialog);
  progressDialog.setIndeterminate(true);
  progressDialog.setMessage("登录中...");
  progressDialog.show();
  //获取输入内容
  String username = et_username.getText().toString().trim();
  String password = et_password.getText().toString().trim();
  //联网，获取数据
  OkGo.get(CONFIG.URL_LOGIN)
    .params("username",username)
    .params("password",password)
    .execute(new StringCallback() {
     @Override
     public void onSuccess(String s,Call call,Response response) {
      Gson gson = new Gson();
      JsonLoginBean jsonLoginBean = gson.fromJson(s,JsonLoginBean.class);
      //如果得到权限>0,则登录成功。
      if (jsonLoginBean.getPermission() > 0) {
       Log.e("zwc","onSuccess: ===");
       onLoginSuccess();
       progressDialog.dismiss();
      } else {
       onLoginFailed();
       progressDialog.dismiss();
      }
     }
    });
 }

 @Override
 protected void onActivityResult(int requestCode,int resultCode,Intent data) {
  if (requestCode == REQUEST_SIGNUP) {
   if (resultCode == RESULT_OK) {
    this.finish();
   }
  }
 }

 /**
  * 重写返回键的返回方法
  */
 @Override
 public void onBackPressed() {
  // Disable going back to the MainActivity
  moveTaskToBack(true);
 }

 /**
  * 登录成功
  */
 public void onLoginSuccess() {
  btn_login.setEnabled(true);
  Intent intent = new Intent(LoginActivity.this,MainActivity.class);
  startActivity(intent);
  finish();
 }

 /**
  * 登录失败
  */
 public void onLoginFailed() {
  Toast.makeText(getBaseContext(),"登陆失败",Toast.LENGTH_LONG).show();
  btn_login.setEnabled(true);
 }

 /**
  * @return 判断是否账号密码是否合法
  */
 public boolean validate() {
  //设置初值，默认为合法
  boolean valid = true;

  //获取输入内容
  String email = et_username.getText().toString().trim();
  String password = et_password.getText().toString().trim();

  //判断账号
  if (email.isEmpty()) {
   et_username.setError("请输入你的账号");
   valid = false;
  } else {
   et_username.setError(null);
  }
  //判断密码
  if (password.isEmpty()) {
   et_password.setError("请输入你的密码");
   valid = false;
  } else {
   et_password.setError(null);
  }

  return valid;
 }
}

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:fitsSystemWindows="true">
 <LinearLayout
  android:orientation="vertical"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:paddingTop="56dp"
  android:paddingLeft="24dp"
  android:paddingRight="24dp">

  <ImageView android:src="@drawable/logo"
   android:layout_width="wrap_content"
   android:layout_height="72dp"
   android:layout_marginBottom="24dp"
   android:layout_gravity="center_horizontal" />

  <!-- 账号 -->
  <android.support.design.widget.TextInputLayout
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginTop="8dp"
   android:layout_marginBottom="8dp">
   <EditText
    android:id="@+id/input_username"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="number"
    android:hint="账号" />
  </android.support.design.widget.TextInputLayout>

  <!-- 密码 -->
  <android.support.design.widget.TextInputLayout
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginTop="8dp"
   android:layout_marginBottom="8dp">
   <EditText android:id="@+id/input_password"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="textPassword"
    android:hint="密码"/>
  </android.support.design.widget.TextInputLayout>

  <android.support.v7.widget.AppCompatButton
   android:id="@+id/btn_login"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_marginTop="24dp"
   android:layout_marginBottom="24dp"
   android:padding="12dp"
   android:text="登陆"/>

  <TextView android:id="@+id/link_signup"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_marginBottom="24dp"
   android:text="没有账号？创建一个"
   android:gravity="center"
   android:textSize="16dip"/>
 </LinearLayout>
</ScrollView>

public class SignupActivity extends BaseActivity {

 EditText _nameText;
 EditText _emailText;
 EditText _passwordText;
 EditText _reEnterPasswordText;
 Button _signupButton;
 TextView _loginLink;

 @Override
 int getLayoutId() {
  return R.layout.activity_signup;
 }

 @Override
 void initView() {
  //根据id找控件
  _nameText = (EditText) findViewById(R.id.input_name);
  _emailText = (EditText) findViewById(R.id.input_username);
  _passwordText = (EditText) findViewById(R.id.input_password);
  _reEnterPasswordText = (EditText) findViewById(R.id.input_reEnterPassword);
  _signupButton = (Button) findViewById(R.id.btn_signup);
  _loginLink = (TextView) findViewById(R.id.link_login);
  _signupButton.setOnClickListener(this);
  _loginLink.setOnClickListener(this);
 }

 @Override
 void processClick(View v) {
  switch (v.getId()) {
   case R.id.btn_signup:
    signup();
    break;
   case R.id.link_login:
    //点击登录连接，跳转到登录页面
    Intent intent = new Intent(getApplicationContext(),LoginActivity.class);
    startActivity(intent);
    finish();
    overridePendingTransition(R.anim.push_left_in,R.anim.push_left_out);
    break;
   default:
    break;
  }
 }

 public void signup() {
  //判断是否合法
  if (!validate()) {
   onSignupFailed(0);
   return;
  }
  _signupButton.setEnabled(false);

  //显示圆形进度条对话框
  final ProgressDialog progressDialog = new ProgressDialog(SignupActivity.this,R.style.AppTheme_Dark_Dialog);
  progressDialog.setIndeterminate(true);
  progressDialog.setMessage("创建账号...");
  progressDialog.show();
  //获取数据
  String username = _nameText.getText().toString();
  String password = _passwordText.getText().toString();
//  联网获取数据
  OkGo.get(CONFIG.URL_SIGNUP)
    .params("username",Response response) {
      Gson gson = new Gson();
      JsonSignupBean jsonSignupBean = gson.fromJson(s,JsonSignupBean.class);
      //如果得到返回消息为ok,则注册成功。
      if (jsonSignupBean.getMsg().equals("ok")) {
       Log.e("zwc","onSuccess: 注册成功");
       onSignupSuccess();
       //对话框消失
       progressDialog.dismiss();
      } else {
       onSignupFailed(1);
       progressDialog.dismiss();
      }
     }
    });
 }

 /**
  * 登陆成功
  */
 public void onSignupSuccess() {
  _signupButton.setEnabled(true);

  Intent intent = new Intent(SignupActivity.this,MainActivity.class);
  startActivity(intent);
  finish();
 }

 /**
  * 注册失败，按钮置为可用
  * 依据传参不同，进行不同吐司
  */
 public void onSignupFailed(int i) {
  if (i == 1) {
   Toast.makeText(getBaseContext(),"该用户名已经被注册",Toast.LENGTH_LONG).show();
  } else {
   Toast.makeText(getBaseContext(),"注册失败",Toast.LENGTH_LONG).show();
  }
  _signupButton.setEnabled(true);
 }

 /**
  * @return 输入内容是否合法
  */
 public boolean validate() {
  boolean valid = true;
  //从控件中获取数据
  String name = _nameText.getText().toString();
  String password = _passwordText.getText().toString();
  String reEnterPassword = _reEnterPasswordText.getText().toString();
  //检测账号是否正确
  if (name.isEmpty()) {
   _nameText.setError("账号不能为空");
   valid = false;
  } else {
   _nameText.setError(null);
  }
  //检测密码是否正确
  if (password.isEmpty()) {
   _passwordText.setError("请输入密码");
   valid = false;
  } else {
   _passwordText.setError(null);
  }
  //检测重复密码是否正确
  if (reEnterPassword.isEmpty() || !(reEnterPassword.equals(password))) {
   _reEnterPasswordText.setError("两次密码不一致");
   valid = false;
  } else {
   _reEnterPasswordText.setError(null);
  }
  return valid;
 }
}

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:fitsSystemWindows="true">

 <LinearLayout
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="vertical"
  android:paddingLeft="24dp"
  android:paddingRight="24dp"
  android:paddingTop="56dp">

  <ImageView
   android:layout_width="wrap_content"
   android:layout_height="72dp"
   android:layout_gravity="center_horizontal"
   android:layout_marginBottom="24dp"
   android:src="@drawable/logo" />

  <!-- 账号 -->
  <android.support.design.widget.TextInputLayout
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginBottom="8dp"
   android:layout_marginTop="8dp">

   <EditText
    android:id="@+id/input_name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="账号"
    android:inputType="textPersonName" />
  </android.support.design.widget.TextInputLayout>

  <!-- 密码 -->
  <android.support.design.widget.TextInputLayout
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginBottom="8dp"
   android:layout_marginTop="8dp">

   <EditText
    android:id="@+id/input_password"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="密码"
    android:inputType="textPassword" />
  </android.support.design.widget.TextInputLayout>

  <!-- 重复密码 -->
  <android.support.design.widget.TextInputLayout
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:layout_marginBottom="8dp"
   android:layout_marginTop="8dp">

   <EditText
    android:id="@+id/input_reEnterPassword"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="重复密码"
    android:inputType="textPassword" />
  </android.support.design.widget.TextInputLayout>

  <android.support.v7.widget.AppCompatButton
   android:id="@+id/btn_signup"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_marginBottom="24dp"
   android:layout_marginTop="24dp"
   android:padding="12dp"
   android:text="创建账号" />

  <TextView
   android:id="@+id/link_login"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_marginBottom="24dp"
   android:gravity="center"
   android:text="已有账号？马上登陆"
   android:textSize="16dip" />

 </LinearLayout>
</ScrollView>

public class AnswerActivity extends BaseActivity implements Chronometer.OnChronometerTickListener {

 private Chronometer chronometer;
 private ViewPager vp_answer;
 private ArrayList<Fragment> fragmentlists;
 private int minute = 0;
 private int second = 0;
 private AlertDialog.Builder builder;
 private ArrayList<String> a;
 private Button btn_previous;
 private Button btn_submit;
 private Button btn_next;
 private int nowpager = 0;
 private List<QuestBean> messages;
 private String type;

 @Override
 int getLayoutId() {
  return R.layout.activity_answer;
 }

 /**
  * 初始化布局
  */
 @Override
 void initView() {
  chronometer = (Chronometer) findViewById(R.id._chro_exam);
  vp_answer = (ViewPager) findViewById(R.id.vp_answer);
  btn_previous = (Button) findViewById(R.id._btn_previous);
  btn_submit = (Button) findViewById(R.id._btn_submit);
  btn_next = (Button) findViewById(R.id._btn_next);
//  获取传递来的变量
  type = getIntent().getExtras().get("type").toString().trim();

//  联网获取数据
  initNet(type);

  btn_previous.setOnClickListener(this);
  btn_submit.setOnClickListener(this);
  btn_next.setOnClickListener(this);
  vp_answer.setOnPageChangeListener(new MyOnPageChangeListener());
  setChronometer();
 }

 /**
  * 设置计时器
  */
 private void setChronometer() {
  chronometer.setText(nowtime());
  chronometer.start();
  chronometer.setOnChronometerTickListener(this);
  chronometer.setOnClickListener(this);
 }

 /**
  * 计时器规则
  *
  * @param chronometer
  */
 @Override
 public void onChronometerTick(Chronometer chronometer) {
  second++;
  if (second == 59) {
   minute++;
   second = 00;
  }
 }

 /**
  * 现在时间
  *
  * @return
  */
 private String nowtime() {
  if (second < 10) {
   return (minute + ":0" + second);
  } else {
   return (minute + ":" + second);
  }
 }

 /**
  * 初始化网络连接
  * @param type
  */
 private void initNet(String type) {
  a = new ArrayList<>();
  fragmentlists = new ArrayList<>();
  Log.e("zwc","initNet: 开始联网…………");
  //进度条对话框
  final ProgressDialog progressDialog = new ProgressDialog(AnswerActivity.this,R.style.AppTheme_Dark_Dialog);
  progressDialog.setIndeterminate(true);
  progressDialog.setMessage("获取题目中...");
  progressDialog.show();
//  联网
  OkGo.get(CONFIG.URL_GETQUEST1)
    .params("type",type)
    .execute(new StringCallback() {
     @Override
     public void onSuccess(String s,Response response) {
      Log.i("zwc","onSuccess: ========---------======" + s);
      //gson解析
      Gson gson = new Gson();
      JsonQuestBean jsonQuestBean = gson.fromJson(s,JsonQuestBean.class);
      messages = jsonQuestBean.getMessages();
      for (int i = 0; i < messages.size(); i++) {
       QuestBean questBeanQ = messages.get(i);
       questBeanQ.setId(i);
       fragmentlists.add(new AnswerFragment(questBeanQ));
       LoveDao.insertLove(questBeanQ);
       a.add(questBeanQ.getId() + "");
       Log.e("zwc",i + "ooooooonSuccessssssssssss: " + questBeanQ.getId() + questBeanQ.getTitle());
      }
//      设置适配器
      vp_answer.setAdapter(new MainAdapter(getSupportFragmentManager()));
      progressDialog.dismiss();
     }

     @Override
     public void onError(Call call,Response response,Exception e) {
      Log.i("zwc","onError///////////////////");
     }
    });
  Log.e("zwc","initNet: 联网结束…………");
 }

 /**
  * viewpager适配器
  */
 class MainAdapter extends FragmentPagerAdapter {

  public MainAdapter(FragmentManager fm) {
   super(fm);
  }

  //获取条目
  @Override
  public Fragment getItem(int position) {
   return fragmentlists.get(position);
  }

  //数目
  @Override
  public int getCount() {
   return fragmentlists.size();
  }
 }

 @Override
 void processClick(View v) {
  switch (v.getId()) {
//   点击上一题按钮
   case R.id._btn_previous:
//    如果是第一题，则谈吐司提醒，否则上移一道题
    if (nowpager == 0) {
     Toast.makeText(AnswerActivity.this,"已经到头啦!",Toast.LENGTH_SHORT).show();
    } else {
     vp_answer.setCurrentItem(--nowpager);
    }
    break;
//   点击提交按钮
   case R.id._btn_submit:
//    简答题不进行提交评分
    if (type.equals("3")) {
     Toast.makeText(this,"简答题目前暂不支持评分",Toast.LENGTH_SHORT).show();
     return;
    }
//    否则初始化并展示提交对话框
    initAlertDialog();
    builder.show();
    break;
//   点击下一题按钮
   case R.id._btn_next:
//    如果是最后一题，则谈吐司提醒，否则下移一道题
    if (nowpager == fragmentlists.size()) {
     Toast.makeText(AnswerActivity.this,"已经是最后一题了!",Toast.LENGTH_SHORT).show();
    } else {
     vp_answer.setCurrentItem(++nowpager);
    }
    break;
   default:
    break;
  }
 }

 // 弹出是否确认交卷的对话框
 private void initAlertDialog() {
  //新建对话框
  builder = new AlertDialog.Builder(AnswerActivity.this);
  builder.setTitle("提示");
  builder.setMessage("是否确定交卷?");
  builder.setPositiveButton("确定",new DialogInterface.OnClickListener() {
   @Override
   public void onClick(DialogInterface dialog,int which) {
    // TODO: 2017/6/14 交卷操作
//    计算分数
    int grade = 0;
//    判断题
    if (type.equals("2")) {
     for (int i = 0; i < messages.size(); i++) {
//      查询
      QuestBean questBeenA = LoveDao.queryLove(Integer.parseInt(a.get(i)));
//      判断
      if (questBeenA.getAnswer().equals("对") && questBeenA.getMyanswer().equals("A") || questBeenA.getAnswer().equals("错") && questBeenA.getMyanswer().equals("B")) {
       grade += 20;
      }
      ;
     }
    }
//    选择题
    else {
     for (int i = 0; i < messages.size(); i++) {
      QuestBean questBeenA = LoveDao.queryLove(Integer.parseInt(a.get(i)));
      if (questBeenA.getAnswer().equals(questBeenA.getMyanswer())) {
       grade += 20;
      }
      ;
     }
    }

//    传递分数
    Intent intent = new Intent(AnswerActivity.this,GradeActivity.class);
    intent.putExtra("grade","" + grade);
//    传递题目列表
    intent.putStringArrayListExtra("timu",a);
    startActivity(intent);
    finish();
   }

  });
  builder.setNegativeButton("取消",null);
 }

 /**
  * viewpager监听事件
  */
 private class MyOnPageChangeListener implements ViewPager.OnPageChangeListener {
  @Override
  public void onPageScrolled(int position,float positionOffset,int positionOffsetPixels) {
  }

  @Override
  public void onPageSelected(int position) {
   nowpager = position;
  }

  @Override
  public void onPageScrollStateChanged(int state) {

  }
 }