Android SQLite数据库连接实现登录功能

本文实例为大家分享了Android SQLite数据库连接实现登录功能的具体代码，供大家参考，具体内容如下

布局文件

border.xml

<?xml version='1.0' encoding='utf-8'?><shape xmlns:android='http://schemas.android.com/apk/res/android' ><!-- 布局的背景颜色--><!-- <solid android:color='#FFFFFF' />--><!-- 边框线的粗细和颜色--> <stroke android: android:color='#000' /> <padding android:bottom='5dp' android:left='5dp' android:right='5dp' android:top='5dp' /><!-- 圆角--> <corners android:radius='5dp' /></shape>

<?xml version='1.0' encoding='utf-8'?><android.support.constraint.ConstraintLayout xmlns:android='http://schemas.android.com/apk/res/android' xmlns:app='http://schemas.android.com/apk/res-auto' xmlns:tools='http://schemas.android.com/tools' android:layout_width='match_parent' android:layout_height='match_parent' tools:context='.MainActivity'><LinearLayoutandroid:padding='5dp'android:background='@drawable/border'android:orientation='vertical'android:layout_gravity='center_horizontal'android:layout_width='360dp'android:layout_height='112dp'> <LinearLayout android:orientation='horizontal' android:layout_gravity='center_horizontal' android:layout_width='match_parent' android:layout_height='50dp'><ImageView android:layout_marginRight='15dp' android:layout_gravity='center_vertical' android:layout_width='30dp' android:layout_height='30dp' app:srcCompat='@drawable/usn' android: /><!-- android:background='@null' 去掉下划线--><EditText android:singleLine='true' android:background='@null' android:layout_width='match_parent' android:layout_height='match_parent' android:inputType='text' android:hint='用户名' android:ems='10' android: /> </LinearLayout> <!-- 水平线--> <View android:layout_height='0.5dip' android:background='#686868' android:layout_width='match_parent'/> <LinearLayout android:orientation='horizontal' android:layout_gravity='center_horizontal' android:layout_width='match_parent' android:layout_height='50dp'><ImageView android:layout_marginRight='15dp' android:layout_gravity='center_vertical' android:layout_width='30dp' android:layout_height='30dp' app:srcCompat='@drawable/pwd' android: /><EditText android:singleLine='true' android:background='@null' android:layout_width='match_parent' android:layout_height='match_parent' android:inputType='textPassword' android:hint='密码' android:ems='10' android: /> </LinearLayout> </LinearLayout> <Buttonandroid:layout_gravity='center_horizontal'android:background='#EF8D89'android:layout_marginTop='20dp'android:text='登 录'android:onClick='userLogin'android:layout_width='360dp'android:layout_height='wrap_content' android: /></android.support.constraint.ConstraintLayout>

MainActivity类

public class MainActivity extends AppCompatActivity implements View.OnClickListener{ //访问数据库的类 SQLiteDatabase db; //定义常量，作为消息的key public final static String MESSAGE_KEY='com.android2'; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); /** * (参数)1、context MainActivity * 2、name 数据库名 * 3、 * 4、版本号 */ final DatabaseHelper databaseHelper = new DatabaseHelper(this,'emis.db',null,2); //获得读取数据库权限 db = databaseHelper.getReadableDatabase(); setContentView(R.layout.activity_main); } /*响应*/ private void userLogin() { EditText et1 = findViewById(R.id.username); String username = et1.getText().toString(); EditText et2 = findViewById(R.id.password); String password = et2.getText().toString(); //游标类Cursor 负责生成读写数据库的对象 Cursor cursor = db.rawQuery('SELECT * FROM users WHERE username=? AND password=?',new String[]{username,password}); //数据库中有此数据，登录成功 if(cursor.getCount()>0){ Intent intent = new Intent(this,ReceiveActivity.class); intent.putExtra(MESSAGE_KEY,username); startActivity(intent); } else{ Toast.makeText(MainActivity.this,'用户名或密码错误!',Toast.LENGTH_SHORT).show(); } }}

ReceiveActivity类及布局

<?xml version='1.0' encoding='utf-8'?><LinearLayout xmlns:android='http://schemas.android.com/apk/res/android' xmlns:tools='http://schemas.android.com/tools' xmlns:app='http://schemas.android.com/apk/res-auto' android:layout_width='match_parent' android:layout_height='match_parent' tools:context='.ReceiveActivity'> <TextView android:textSize='24dp' android:layout_gravity='center_vertical' android: android:layout_width='match_parent' android:layout_height='match_parent' /></LinearLayout>

package com.android02;import android.content.Intent;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.widget.TextView;public class ReceiveActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_receive); //获取intent引用 Intent intent = getIntent(); //以MESSAGE_KEY获取获取编辑框文字 String message = intent.getStringExtra(MainActivity.MESSAGE_KEY); //以id获取TextView TextView textView = findViewById(R.id.output); //显示message textView.setText('欢迎!'+message); }}

测试：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持好吧啦网。