个人冲刺（四）——体温上报app（二阶段）

冲刺任务：完成用户注册功能和数据库类

RegisterActivity.java

package com.example.helloworld;
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.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
/**
 * Created by littlecurl 2018/6/24
 */
/**
 * 此类 implements View.OnClickListener 之后，
 * 就可以把onClick事件写到onCreate()方法之外
 * 这样，onCreate()方法中的代码就不会显得很冗余
 */
public class RegisterActivity extends AppCompatActivity implements View.OnClickListener {

    private String realCode;
    private DBOpenHelper mDBOpenHelper;
    private Button mBtRegisteractivityRegister;
    private RelativeLayout mRlRegisteractivityTop;
    private ImageView mIvRegisteractivityBack;
    private LinearLayout mLlRegisteractivityBody;
    private EditText mEtRegisteractivityUsername;
    private EditText mEtRegisteractivityUserid;
    private EditText mEtRegisteractivityUserphone;
    private EditText mEtRegisteractivityUseraddress;
    private EditText mEtRegisteractivityPhonecodes;
    private ImageView mIvRegisteractivityShowcode;
    private RelativeLayout mRlRegisteractivityBottom;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);

        initView();

        mDBOpenHelper = new DBOpenHelper(this);

        //将验证码用图片的形式显示出来
        mIvRegisteractivityShowcode.setImageBitmap(Code.getInstance().createBitmap());
        realCode = Code.getInstance().getCode().toLowerCase();
    }

    private void initView(){
        mBtRegisteractivityRegister = findViewById(R.id.bt_registeractivity_register);
        mRlRegisteractivityTop = findViewById(R.id.rl_registeractivity_top);
        mIvRegisteractivityBack = findViewById(R.id.iv_registeractivity_back);
        mLlRegisteractivityBody = findViewById(R.id.ll_registeractivity_body);
        mEtRegisteractivityUsername = findViewById(R.id.et_registeractivity_name);
        mEtRegisteractivityUserid = findViewById(R.id.et_registeractivity_id);
        mEtRegisteractivityUserphone = findViewById(R.id.et_registeractivity_phone);
        mEtRegisteractivityUseraddress = findViewById(R.id.et_registeractivity_address);
        mEtRegisteractivityPhonecodes = findViewById(R.id.et_registeractivity_phoneCodes);
        mIvRegisteractivityShowcode = findViewById(R.id.iv_registeractivity_showCode);
        mRlRegisteractivityBottom = findViewById(R.id.rl_registeractivity_bottom);

        /**
         * 注册页面能点击的就三个地方
         * top处返回箭头、刷新验证码图片、注册按钮
         */
        mIvRegisteractivityBack.setOnClickListener(this);
        mIvRegisteractivityShowcode.setOnClickListener(this);
        mBtRegisteractivityRegister.setOnClickListener(this);
    }

    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.iv_registeractivity_back: //返回登录页面
                Intent intent1 = new Intent(this, loginActivity.class);
                startActivity(intent1);
                finish();
                break;
            case R.id.iv_registeractivity_showCode:    //改变随机验证码的生成
                mIvRegisteractivityShowcode.setImageBitmap(Code.getInstance().createBitmap());
                realCode = Code.getInstance().getCode().toLowerCase();
                break;
            case R.id.bt_registeractivity_register:    //注册按钮
                //获取用户输入的用户名、密码、验证码
                String username = mEtRegisteractivityUsername.getText().toString().trim();
                String userid = mEtRegisteractivityUserid.getText().toString().trim();
                String userphone = mEtRegisteractivityUserphone.getText().toString().trim();
                String useraddress = mEtRegisteractivityUseraddress.getText().toString().trim();
                String phoneCode = mEtRegisteractivityPhonecodes.getText().toString().toLowerCase();
                //注册验证
                if (!TextUtils.isEmpty(username) && !TextUtils.isEmpty(userid) && !TextUtils.isEmpty(phoneCode) && !TextUtils.isEmpty(userphone)
                        && !TextUtils.isEmpty(useraddress)    ) {
                    if (phoneCode.equals(realCode)) {
                        //将用户名和密码加入到数据库中
                        mDBOpenHelper.add(username, userid,userphone,useraddress);
                        Intent intent2 = new Intent(this, MainActivity.class);
                        startActivity(intent2);
                        finish();
                        Toast.makeText(this,  "验证通过，注册成功", Toast.LENGTH_SHORT).show();
                    } else {
                        Toast.makeText(this, "验证码错误,注册失败", Toast.LENGTH_SHORT).show();
                    }
                }else {
                    Toast.makeText(this, "未完善信息，注册失败", Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }
}

MyDBHelper.java

package com.example.helloworld;

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

import androidx.annotation.Nullable;

public class MyDBHelper extends SQLiteOpenHelper {
    private Context context;
    public MyDBHelper(Context context,String name,int version) {
        super(context, name, null, version);
        this.context=context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String sql="create table IF NOT EXISTS personwendu(id integer primary key autoincrement, address varchar, name varchar, wendu varchar, dateandtime varchar,more varchar)";
        db.execSQL(sql);
        Toast.makeText(context,"数据加入成功",Toast.LENGTH_LONG).show();
    }

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

DBOpenHelper.java

package com.example.helloworld;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

import java.util.ArrayList;

public class DBOpenHelper extends SQLiteOpenHelper {
    /**
     * 声明一个AndroidSDK自带的数据库变量db
     */
    private SQLiteDatabase db;

    /**
     * 写一个这个类的构造函数，参数为上下文context，所谓上下文就是这个类所在包的路径
     * 指明上下文，数据库名，工厂默认空值，版本号默认从1开始
     * super(context,"db_test",null,1);
     * 把数据库设置成可写入状态，除非内存已满，那时候会自动设置为只读模式
     * 不过，以现如今的内存容量，估计一辈子也见不到几次内存占满的状态
     * db = getReadableDatabase();
     */
    public DBOpenHelper(Context context){
        super(context,"db_test",null,1);
        db = getReadableDatabase();
    }

    /**
     * 重写两个必须要重写的方法，因为class DBOpenHelper extends SQLiteOpenHelper
     * 而这两个方法是 abstract 类 SQLiteOpenHelper 中声明的 abstract 方法
     * 所以必须在子类 DBOpenHelper 中重写 abstract 方法
     * 想想也是，为啥规定这么死必须重写？
     * 因为，一个数据库表，首先是要被创建的，然后免不了是要进行增删改操作的
     * 所以就有onCreate()、onUpgrade()两个方法
     * @param db
     */
    @Override
    public void onCreate(SQLiteDatabase db){
        db.execSQL("CREATE TABLE IF NOT EXISTS user(" +
                "_id INTEGER PRIMARY KEY AUTOINCREMENT," +
                "username TEXT," +
                "userid TEXT,"+
                "userphone TEXT,"+
                "useraddress TEXT)"
        );
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
        db.execSQL("DROP TABLE IF EXISTS user");
        onCreate(db);
    }
    /**
     * 接下来写自定义的增删改查方法
     * 这些方法，写在这里归写在这里，以后不一定都用
     * add()
     * delete()
     * update()
     * getAllData()
     */
    public void add(String username,String userid,String userphone,String useraddress){
        db.execSQL("INSERT INTO user (username,userid,userphone,useraddress) VALUES(?,?,?,?)",
                new Object[]{username,userid,userphone,useraddress});
    }
    public void delete(String userphone){
        db.execSQL("DELETE FROM user WHERE userphone = "+userphone);
    }
    public void updata(String userphone){
        db.execSQL("UPDATE user SET userphone = ?",new Object[]{userphone});
    }

    /**
     * 前三个没啥说的，都是一套的看懂一个其他的都能懂了
     * 下面重点说一下查询表user全部内容的方法
     * 我们查询出来的内容，需要有个容器存放，以供使用，
     * 所以定义了一个ArrayList类的list
     * 有了容器，接下来就该从表中查询数据了，
     * 这里使用游标Cursor，这就是数据库的功底了，
     * 在Android中我就不细说了，因为我数据库功底也不是很厚，
     * 但我知道，如果需要用Cursor的话，第一个参数："表名"，中间5个：null，
     *                                                     最后是查询出来内容的排序方式："name DESC"
     * 游标定义好了，接下来写一个while循环，让游标从表头游到表尾
     * 在游的过程中把游出来的数据存放到list容器中
     * @return
     */
    public ArrayList<User> getAllData(){

        ArrayList<User> list = new ArrayList<User>();
        Cursor cursor = db.query("user",null,null,null,null,null,"username DESC");
        cursor.moveToFirst();
        while(cursor.moveToNext()){
            String username = cursor.getString(cursor.getColumnIndex("username"));
            String userid = cursor.getString(cursor.getColumnIndex("userid"));
            String userphone = cursor.getString(cursor.getColumnIndex("userphone"));
            String useraddress = cursor.getString(cursor.getColumnIndex("useraddress"));
            list.add(new User(username,userid,userphone,useraddress));
        }
        Log.v("输出数据库查询结果：",list.toString());
        return list;
    }
}