代码记录

activity_login.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    
    <LinearLayout
        android:id="@+id/layout1"
        android:layout_alignParentTop="true"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="60dp">
        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:textSize="18sp"
            android:text="账号:" />

        <EditText
            android:id="@+id/account"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:layout_gravity="center_vertical"/>
    </LinearLayout>

    <LinearLayout
        android:id="@+id/layout2"
        android:layout_below="@id/layout1"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="60dp">
        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:textSize="18sp"
            android:text="密码:" />

        <EditText
            android:id="@+id/password"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:layout_gravity="center_vertical"
            android:inputType="textPassword" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/layout3"
        android:layout_below="@id/layout2"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <CheckBox
            android:id="@+id/remember_pass"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="18sp"
            android:text="记住密码" />

    </LinearLayout>

    <Button
        android:id="@+id/login"
        android:layout_below="@id/layout3"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:background="#FF4081"
        android:text="登录" />

    <Button
        android:id="@+id/register"
        android:layout_alignParentBottom="true"
        android:layout_centerInParent="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#ffffff"
        android:textSize="16sp"
        android:textColor="#928E8E"
        android:text="注册" />

</RelativeLayout>


loginActivity.java:

package com.example.bizarredictionary;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;


public class LoginActivity extends BaseActivity implements View.OnClickListener{

    private SharedPreferences pref;

    private SharedPreferences.Editor editor;

    private EditText accountEdit;

    private EditText passwordEdit;

    private Button login, register;

    private CheckBox rememberPass;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        pref = PreferenceManager.getDefaultSharedPreferences(this); //获取SharedPreferences对象,自动使用当前应用程序的包名作为前缀来命名SharedPreferences文件。
        accountEdit = (EditText) findViewById(R.id.account);
        passwordEdit = (EditText) findViewById(R.id.password);
        rememberPass = (CheckBox) findViewById(R.id.remember_pass);

        Button login = findViewById(R.id.login);
        Button regidter = findViewById(R.id.register);
        login.setOnClickListener(this);
        regidter.setOnClickListener(this);

        boolean isRemember = pref.getBoolean("remember_password", false);
        boolean iskeep = pref.getBoolean("keep_login", false);

        if (iskeep) {
            Intent intent = new Intent(LoginActivity.this, MainActivity.class);
            startActivity(intent);
            finish();
        }
        if (isRemember) {
            // 将账号和密码都设置到文本框中
            String account = pref.getString("account", "");
            String password = pref.getString("password", "");
            accountEdit.setText(account);
            passwordEdit.setText(password);
            rememberPass.setChecked(true);
        }
    }

    @Override
    public void onClick(View v) {
        String account = accountEdit.getText().toString();
        String password = passwordEdit.getText().toString();
        switch(v.getId()){
            case R.id.login:
                // 如果账号是admin且密码是123456，就认为登录成功
                if (account.equals("admin") && password.equals("123456")) {
                    editor = pref.edit();
                    if (rememberPass.isChecked()) { // 检查复选框是否被选中
                        editor.putBoolean("remember_password", true);
                        editor.putString("account", account);
                        editor.putString("password", password);
                    } else {
                        editor.clear();
                    }
                    editor.putBoolean("keep_login", true);
                    editor.apply();

                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                    startActivity(intent);
                    finish();
                } else {
                    Toast.makeText(LoginActivity.this, "account or password is invalid",
                            Toast.LENGTH_SHORT).show();
                }

            case R.id.register:
                //if (account.equals(db.))
                break;

        }
    }
}