安卓学习---SqLite实现登录注册

前段时间学习数据存储，sp，内部，外部文件存储，SqLite数据库存储。学完利空课余时间写了一个实现登录注册的demo
先看一下效果图吧



接下来看代码，布局文件代码太简单了我就不贴出来了
注册代码

package com.example.xiaofeiwa.myqqloginapplication;

import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class ResterActivity extends AppCompatActivity {
    MySqLiteHelper helper = null;
    private EditText register_user, register_password;
    private Button register_suer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_rester);
        //创建数据库
        helper = new MySqLiteHelper(this, "SAVE_USER.db", null, 1);
        SQLiteDatabase database = helper.getReadableDatabase();
        initViews();

    }

    private void initViews() {
        register_user = findViewById(R.id.et_register_user);
        register_password = findViewById(R.id.et_register_password);
        register_suer = findViewById(R.id.btn_register_suer);
        //点击确定按钮返回登录界面
        register_suer.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            	//trim()去空格
                String RegisterUser = register_user.getText().toString().trim();
                String RegisterPassword = register_password.getText().toString().trim();
                //判断输入的账号密码是否为空，是则提示用户输入正确的
                if (RegisterUser.equals("") && RegisterPassword.equals("")) {
                    Toast.makeText(ResterActivity.this, "请输入账号/密码", Toast.LENGTH_LONG).show();
                } else {
                //账号密码有效，执行下一步
                    /**
                     * 把获取的数据存储到数据库
                     * 1.insert方法添加数据到数据库
                     */
                    SQLiteDatabase database = helper.getReadableDatabase();
                    ContentValues values = new ContentValues();
                    //键值对的形式
                    values.put("name", RegisterUser);
                    values.put("password", RegisterPassword);
                    //添加到user表
                    database.insert("user", null, values);
                    Toast.makeText(ResterActivity.this, "数据保存成功", Toast.LENGTH_LONG).show();
                    //账号密码验证正确，显示意图跳转到登录界面
                    //Toast.makeText(ResterActivity.this, "注册成功", Toast.LENGTH_LONG).show();
                    Intent intent;
                    intent = new Intent(ResterActivity.this, MainActivity.class);
                    startActivity(intent);
                }
//                if (RegisterUser.length() != 11){
//                    Toast.makeText(ResterActivity.this, "请输入正确手机号", Toast.LENGTH_LONG).show();
//                }
            }
        });
    }
}

MySqLiteHelper类

package com.example.xiaofeiwa.myqqloginapplication;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

public class MySqLiteHelper extends SQLiteOpenHelper {
    private static final String LAN_USER = "create table user(name text,password text)";
    Context context;

    public MySqLiteHelper(Context context,String name,SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
        this.context = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(LAN_USER);
        Toast.makeText(context,"数据库创建成功！",Toast.LENGTH_LONG).show();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    }
}

MainActivity

package com.example.xiaofeiwa.myqqloginapplication;

import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    MySqLiteHelper helper;
    private EditText user, password;
    private Button login, register;
    private String name;
    private String psd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //数据库操作
        helper = new MySqLiteHelper(this, "SAVE_USER.db", null, 1);
        SQLiteDatabase database = helper.getReadableDatabase();
        Cursor cursor = database.rawQuery("select * from user", null);
        if (cursor.moveToFirst()) {
            do {
                //从数据库获取到用户名、密码
                name = cursor.getString(cursor.getColumnIndex("name"));
                psd = cursor.getString(cursor.getColumnIndex("password"));
            } while (cursor.moveToNext());
            //关闭游标
            cursor.close();
        }
        initViews();
    }

    private void initViews() {
        user = findViewById(R.id.et_user);
        password = findViewById(R.id.et_password);
        login = findViewById(R.id.btn_login);
        register = findViewById(R.id.btn_register);
        //注册按钮点击事件
        register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, ResterActivity.class);
                startActivity(intent);
            }
        });
        //登录按钮点击事件
        //验证当前账号、密码是否跟注册报讯在数据库的账号、密码一致，一致则允许登录
        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //获取输入框文本
                String username = user.getText().toString().trim();
                String mpassword = password.getText().toString().trim();
                //database.query("user",null,null,null,null,null,null);
                if (username.equals("") && mpassword.equals("")) {
                    Toast.makeText(MainActivity.this, "账号/密码不能为空", Toast.LENGTH_LONG).show();
                } else {
                    sureuser(username, mpassword);
                }
            }
        });
    }
    private void sureuser(String username, String mpassword) {
        if (username.equals(name) && mpassword.equals(psd)) {
            //账号密码校验正确
            // 登陆成功，跳转的用户界面
            Intent intent = new Intent(this, UserActivity.class);
            startActivity(intent);
            //提示
            Toast.makeText(MainActivity.this, "登陆成功！", Toast.LENGTH_LONG).show();
        } else {
            Toast.makeText(MainActivity.this, "手机号/密码错误！", Toast.LENGTH_LONG).show();
        }
    }
}

至于登陆成功的界面就不贴出来了，大家自由发挥