安卓如何书写注册和登录界面

一、如何跳转一个活动

左边的是本活动名称，右边的是跳转界面活动名称

Intent intent = new Intent(LoginActivity.this, RegisterActivity.class);
startActivity(intent);
finish();

二、如果在不同的界面传递参数

//发送消息
SharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("username", username);
editor.putString("password", password);
editor.apply(); 

//接收消息
SharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);
String savedUsername = sharedPreferences.getString("username", "");
String savedPassword = sharedPreferences.getString("password", "");

三、如何让图片是按钮

<ImageButton
            android:id="@+id/imageButton"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:src="@drawable/s7" />

四、登录界面

1、创建一个LoginActivity类，然后创建对应的界面文件.xml

2、注册登录界面，并让登录界面其成为主界面

        <activity
            android:name=".LoginActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".MainActivity"/>
        <activity android:name=".RegisterActivity"/>

3、书写登录界面

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="20dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="账号："
        android:textSize="20dp"/>

    <EditText
        android:id="@+id/usernameEditText"
        android:layout_width="180dp"
        android:layout_height="wrap_content"
        android:textSize="20dp"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="密码："
            android:textSize="20dp"/>

        <EditText
            android:id="@+id/passwordEditText"
            android:layout_width="180dp"
            android:layout_height="wrap_content"
            android:textSize="20dp"/>
    </LinearLayout>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="20dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">

        <CheckBox
            android:id="@+id/rememberPasswordCheckbox"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="记住密码"
            android:layout_gravity="start"
            android:layout_marginStart="16dp"
            android:layout_marginTop="8dp"/>

        <TextView
            android:layout_width="80dp"
            android:layout_height="wrap_content"/>

        <Button
            android:id="@+id/zcButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="点击注册" />
    </LinearLayout>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="20dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">
        <Button
            android:id="@+id/loginButton"
            android:layout_width="200dp"
            android:layout_height="wrap_content"
            android:text="确认登录" />
    </LinearLayout>

</LinearLayout>

4、书写登录活动代码

package com.example.yaodian;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class LoginActivity extends AppCompatActivity {

    EditText usernameEditText;
    EditText passwordEditText;
    Button loginButton;
    Button zcButton;

    CheckBox rememberPasswordCheckbox ;



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

        rememberPasswordCheckbox = findViewById(R.id.rememberPasswordCheckbox);
        usernameEditText = findViewById(R.id.usernameEditText);
        passwordEditText = findViewById(R.id.passwordEditText);
        loginButton = findViewById(R.id.loginButton);
        zcButton = findViewById(R.id.zcButton);
        loginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                String inputUsername = usernameEditText.getText().toString();
                String inputPassword = passwordEditText.getText().toString();

                SharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);
                String savedUsername = sharedPreferences.getString("username", "");
                String savedPassword = sharedPreferences.getString("password", "");

                // 在这里添加登录验证逻辑
                if (inputUsername.equals(savedUsername) && inputPassword.equals(savedPassword)) {
                    Toast.makeText(LoginActivity.this, "登录成功", Toast.LENGTH_SHORT).show();

                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                    startActivity(intent);
                    finish();
                    // 跳转到 MainActivity 或其他操作
                } else {

                    new AlertDialog.Builder(LoginActivity.this)
                            .setTitle("提示")
                            .setMessage("登录失败，用户名或密码错误")
                            .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialog, int which) {
                                }
                            })
                            .show();
                }

            }
        });

        zcButton.setOnClickListener((l) -> {
            Intent intent = new Intent(LoginActivity.this, RegisterActivity.class);
            startActivity(intent);
            finish();
        });


//        // 监听复选框状态变化
//        rememberPasswordCheckbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
//            @Override
//            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
//                // 根据复选框状态来处理记住密码逻辑
//                if (isChecked) {
//
//                } else {
//
//                }
//            }
//        });
    }
}

五、注册界面

同登录界面

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="20dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="       账号："
            android:textSize="20dp"/>

        <EditText
            android:id="@+id/usernameEditText"
            android:layout_width="180dp"
            android:layout_height="wrap_content"
            android:textSize="20dp"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="       密码："
            android:textSize="20dp"/>

        <EditText
            android:id="@+id/passwordEditText"
            android:layout_width="180dp"
            android:layout_height="wrap_content"
            android:textSize="20dp"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="确认密码："
            android:textSize="20dp"/>

        <EditText
            android:id="@+id/password2EditText"
            android:layout_width="180dp"
            android:layout_height="wrap_content"
            android:textSize="20dp"/>
    </LinearLayout>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="50dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center">
        <Button
            android:id="@+id/registerButton"
            android:layout_width="200dp"
            android:layout_height="wrap_content"
            android:text="确认注册" />
    </LinearLayout>

</LinearLayout>

package com.example.yaodian;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class RegisterActivity extends AppCompatActivity {

    private EditText usernameEditText;
    private EditText passwordEditText;

    private EditText password2EditText;
    private Button registerButton;

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

        usernameEditText = findViewById(R.id.usernameEditText);
        passwordEditText = findViewById(R.id.passwordEditText);
        password2EditText = findViewById(R.id.password2EditText);
        registerButton = findViewById(R.id.registerButton);

        registerButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String username = usernameEditText.getText().toString().trim();
                String password = passwordEditText.getText().toString().trim();
                String password2 = password2EditText.getText().toString().trim();

                if (username.isEmpty() || password.isEmpty()) {
                    // 弹出“请输入账号和密码”的对话框
                    new AlertDialog.Builder(RegisterActivity.this)
                            .setTitle("提示")
                            .setMessage("请输入账号和密码")
                            .setPositiveButton("确定", null)
                            .show();
                } else if (!password.equals(password2)) {
                    // 弹出“两次密码不一样，请重新输入”的对话框
                    new AlertDialog.Builder(RegisterActivity.this)
                            .setTitle("提示")
                            .setMessage("两次密码不一样，请重新输入")
                            .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialog, int which) {
                                    // 清空密码和确认密码输入框
                                    passwordEditText.setText("");
                                    password2EditText.setText("");
                                }
                            })
                            .show();
                } else {
                    // 保存注册信息到 SharedPreferences
                    SharedPreferences sharedPreferences = getSharedPreferences("MyPrefs", MODE_PRIVATE);
                    SharedPreferences.Editor editor = sharedPreferences.edit();
                    editor.putString("username", username);
                    editor.putString("password", password);
                    editor.apply();

                    Toast.makeText(RegisterActivity.this, "注册成功", Toast.LENGTH_SHORT).show();

                    Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);
                    startActivity(intent);
                    finish();


                }



            }
        });
    }
}