一、项目结构
二、登录页面xml布局
activity_login.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/green_200">
<ImageView
android:layout_width="100dp"
android:layout_height="100dp"
android:src="@drawable/profilepicture"
android:layout_marginTop="100dp"
android:layout_gravity="center_horizontal"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="30dp"
android:text="账号:"
android:textSize="30dp" />
<EditText
android:id="@+id/loginAccount"
android:layout_width="245dp"
android:hint="请输入账号"
android:inputType="number"
style="@style/edit_text" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="20dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="密码:"
android:textSize="30dp"
android:paddingLeft="30dp"/>
<EditText
android:id="@+id/loginKey"
android:layout_width="247dp"
android:hint="请输入密码"
android:inputType="numberPassword"
style="@style/edit_text"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="100dp"
android:orientation="horizontal"
android:gravity="center_horizontal">
<Button
android:id="@+id/loginBtn"
android:text="登录"
android:textSize="40dp"
style="@style/btn"/>
<Button
android:id="@+id/lRegiterBtn"
android:text="注册"
android:textSize="40dp"
android:layout_marginLeft="100dp"
style="@style/btn"/>
</LinearLayout>
</LinearLayout>
三、注册页面xml文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/green_200">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="150dp"
android:layout_gravity="center_vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="账  号:"
android:textSize="30dp"
android:paddingLeft="10dp"/>
<EditText
android:id="@+id/regiterAccount"
android:layout_width="209dp"
android:hint="请输入账号"
android:inputType="number"
style="@style/edit_text"/>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="20dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="密  码:"
android:textSize="30dp"
android:paddingLeft="10dp"/>
<EditText
android:id="@+id/registerKey"
android:layout_width="209dp"
android:hint="请输入密码"
android:inputType="numberPassword"
style="@style/edit_text" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="10dp"
android:text="确认密码:"
android:textSize="30dp" />
<EditText
android:id="@+id/registerKey2"
android:layout_width="209dp"
android:hint="请再次输入密码"
android:inputType="numberPassword"
style="@style/edit_text" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="20dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30dp"
android:paddingLeft="10dp"
android:text="邮  箱:"
/>
<EditText
android:id="@+id/registerMail"
android:layout_width="209dp"
android:hint="请输入邮箱账号"
android:inputType="textEmailAddress"
style="@style/edit_text"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="80dp"
android:orientation="horizontal"
android:gravity="center_horizontal">
<Button
android:id="@+id/registerBackBtn"
android:text="返回"
android:textSize="40dp"
style="@style/btn"/>
<Button
android:id="@+id/regiterBtn"
android:text="注册"
android:textSize="40dp"
android:layout_marginLeft="100dp"
style="@style/btn"/>
</LinearLayout>
</LinearLayout>
四、实体类
User
package com.example.login.model;
public class User {
public String account;
public String loginKey;
public String mail;
public User() {
}
public User(String account, String loginKey, String mail) {
this.account = account;
this.loginKey = loginKey;
this.mail = mail;
}
public String getAccount() {
return account;
}
public void setAccount(String account) {
this.account = account;
}
public String getLoginKey() {
return loginKey;
}
public void setLoginKey(String loginKey) {
this.loginKey = loginKey;
}
public String getMail() {
return mail;
}
public void setMail(String mail) {
this.mail = mail;
}
@Override
public String toString() {
return "User{" +
"account='" + account + '\'' +
", loginKey='" + loginKey + '\'' +
", mail='" + mail + '\'' +
'}';
}
}
五、数据库操作类
MySQLiteOpenHelper
package com.example.login;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
public class MySQLiteOpenHelper extends SQLiteOpenHelper {
private SQLiteDatabase db; //声明一个数据库变量db
private static final String DB_NAME="mySQLite.db";
private static final String TABLE_NAME="user";
// public MySQLiteOpenHelper(@Nullable Context context, @Nullable String name, @Nullable SQLiteDatabase.CursorFactory factory, int version) {
// super(context, name, factory, version);
//简化后,仅需传入contex(上下文)一个参数即可创建MySQLiteOpenHelper对象
public MySQLiteOpenHelper(@Nullable Context context) {
super(context, DB_NAME, null, 1);
db=getReadableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
//创建数据库SQL语句
String CREATE_TABLE_SQL= "create table "+TABLE_NAME+" (id Integer primary key autoincrement,account text,login_key text,mail text)";
//创建数据库表
db.execSQL(CREATE_TABLE_SQL);
}
@Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
//更新需做的操作
db.execSQL("drop table if exists "+TABLE_NAME);
onCreate(db);
}
//插入用户
public void insert(String account,String loginKey,String mail){
String INSERT_USER_SQL="insert into "+TABLE_NAME+" (account,login_key,mail) values(?,?,?)";
db.execSQL(INSERT_USER_SQL,new Object[]{account,loginKey,mail});
}
//根据账号查找密码
public String queryKeyByAcount(String account){
String QUERY_KEY_BYACOUNT_SQL="select login_key from "+TABLE_NAME+" where account=?";
//rawQuery()⽅法的第⼀个参数为select语句;第⼆个参数为select语句中占位符参数的值,如果select语句没有使⽤占位符,该参数可以设置为null。
Cursor cursor=db.rawQuery(QUERY_KEY_BYACOUNT_SQL,new String[]{account});
//因为账号是唯一的,所以查找的结果有且只有一条,直接将游标的指向为first即可
cursor.moveToFirst();
String loginKey=cursor.getString(0);
//关闭游标
cursor.close();
return loginKey;
}
//在数据库中查找账号是否已经存在
public Integer queryCountByAccount(String account){
Cursor cursor=db.rawQuery("select count(*) from "+TABLE_NAME+" where account=?",new String[]{account});
cursor.moveToFirst();
int count=cursor.getInt(0);
cursor.close();
return count;
}
}
六、登录活动
package com.example.login;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
public class LoginActivity extends AppCompatActivity implements View.OnClickListener {
private EditText loginAcount, loginKey;
private Button loginBtn, lRegisterBtn;
private Intent jump_to_page1, jump_to_register;
private MySQLiteOpenHelper db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
//初始化UI界面
initView();
//申明自己写的MySQLiteOpenHelper对象,主要用来创建数据表,然后再进行数据表的增、删、改、查操作
db = new MySQLiteOpenHelper(this);
}
private void initView() {
loginAcount=(EditText)findViewById(R.id.loginAccount);
loginKey=(EditText)findViewById(R.id.loginKey);
loginBtn=(Button)findViewById(R.id.loginBtn);
lRegisterBtn=(Button)findViewById(R.id.lRegiterBtn);
//设置监听器
loginBtn.setOnClickListener(this);
lRegisterBtn.setOnClickListener(this);
//修改标题栏
getSupportActionBar().setTitle("登录页面");
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.loginBtn:
//获取输入的账号和密码
String account = loginAcount.getText().toString();
String key1 = loginKey.getText().toString();
if (!TextUtils.isEmpty(account) && !TextUtils.isEmpty(key1)) { //判断账号、密码是否都不为空
if (db.queryCountByAccount(account) != 0) { //账号是否存在
if (TextUtils.equals(key1, db.queryKeyByAcount(account))) { //输入的密码与数据库中账号对应的密码是否相等
//提示登录成功
Toast.makeText(this, "登录成功", Toast.LENGTH_LONG).show();
//跳转到登录后的页面
jump_to_page1 = new Intent(LoginActivity.this, Page1Activity.class);
startActivity(jump_to_page1);
finish();//销毁此Activity
} else {
//提示输入密码或账号不正确
Toast.makeText(this, "账号或密码不正确", Toast.LENGTH_LONG).show();
}
} else {
//提示输入账号不存在
Toast.makeText(this, "账号不存在", Toast.LENGTH_LONG).show();
}
} else {
//提示输入密码或账号不能为空
Toast.makeText(this, "账号或密码不能为空", Toast.LENGTH_LONG).show();
}
break;
case R.id.lRegiterBtn:
//跳转到注册页面
jump_to_register = new Intent(LoginActivity.this, RegisterActivity.class);
startActivity(jump_to_register);
finish();//销毁此Activity
break;
default:
break;
}
}
}
七、注册页面活动
package com.example.login;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class RegisterActivity extends AppCompatActivity implements View.OnClickListener {
private EditText regiterAcount,registerKey1,registerMail,registerKey2;
private Button registerBackBtn,registerBtn;
private Intent jump_to_page1,jump_to_login;
private MySQLiteOpenHelper db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
//初始化注册页面
initView();
//申明自己写的MySQLiteOpenHelper对象,主要用来创建数据表,然后再进行数据表的增、删、改、查操作
db=new MySQLiteOpenHelper(this);
}
private void initView(){
regiterAcount=(EditText)findViewById(R.id.regiterAccount);
registerKey1=(EditText)findViewById(R.id.registerKey);
registerKey2=(EditText)findViewById(R.id.registerKey2);
registerMail=(EditText)findViewById(R.id.registerMail);
registerBackBtn=(Button)findViewById(R.id.registerBackBtn);
registerBtn=(Button)findViewById(R.id.regiterBtn);
//设置监听器
registerBackBtn.setOnClickListener(this);
registerBtn.setOnClickListener(this);
//修改标题栏
getSupportActionBar().setTitle("注册页面");
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.registerBackBtn:
//返回到登录页面
jump_to_login=new Intent(this,LoginActivity.class);
startActivity(jump_to_login);
finish();//销毁此Activity
break;
case R.id.regiterBtn:
//获取用户输入的账号、密码、邮箱
String account=regiterAcount.getText().toString();
String key1=registerKey1.getText().toString();
String key2=registerKey2.getText().toString();
String mail=registerMail.getText().toString();
if(!TextUtils.isEmpty(account)&& !TextUtils.isEmpty(key1) && !TextUtils.isEmpty(key2)){ //邮箱为空也可进行注册
if(db.queryCountByAccount(account)==0){ //输入的账号在数据库中不存在
if(TextUtils.equals(key1,key2)){ //两次输入密码一致
//向数据库中插入数据
db.insert(account,key1,mail);
//提示注册成功
Toast.makeText(this,"注册成功",Toast.LENGTH_LONG).show();
//跳转到登录后页面
jump_to_page1=new Intent(this,Page1Activity.class);
startActivity(jump_to_page1);
finish();//销毁此Activity
}else{
//提示两次输入密码不一致
Toast.makeText(this,"两次输入密码不一致",Toast.LENGTH_LONG).show();
}
}else{
//提示账号已存在
Toast.makeText(this,"账号已存在",Toast.LENGTH_LONG).show();
}
}else{
//提示输入的账号、密码不能为空
Toast.makeText(this,"输入的账号密码不能为空",Toast.LENGTH_LONG).show();
}
break;
default:
break;
}
}
}