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
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);
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);
}
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
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考高分网。



