安卓学习
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();
}
}
}