Android studio 编写登录注册代码

以下是一个简单的示例代码，用于实现登录和注册功能：

1. activity_login.xml 布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">

    <EditText
        android:id="@+id/username_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Username"/>

    <EditText
        android:id="@+id/password_edit_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="textPassword"
        android:hint="Password"/>

    <Button
        android:id="@+id/login_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Login"/>

    <Button
        android:id="@+id/register_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Register"/>

</LinearLayout>

2. LoginActivity.java 代码：

public class LoginActivity extends AppCompatActivity {

    private EditText mUsernameEditText;
    private EditText mPasswordEditText;

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

        mUsernameEditText = findViewById(R.id.username_edit_text);
        mPasswordEditText = findViewById(R.id.password_edit_text);

        Button loginButton = findViewById(R.id.login_button);
        loginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String username = mUsernameEditText.getText().toString();
                String password = mPasswordEditText.getText().toString();
                // 处理登录逻辑
                if (TextUtils.isEmpty(username)) {
                    Toast.makeText(LoginActivity.this, "Please enter your username", Toast.LENGTH_SHORT).show();
                } else if (TextUtils.isEmpty(password)) {
                    Toast.makeText(LoginActivity.this, "Please enter your password", Toast.LENGTH_SHORT).show();
                } else {
                    // 登录成功
                    Toast.makeText(LoginActivity.this, "Login success", Toast.LENGTH_SHORT).show();
                }
            }
        });

        Button registerButton = findViewById(R.id.register_button);
        registerButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String username = mUsernameEditText.getText().toString();
                String password = mPasswordEditText.getText().toString();
                // 处理注册逻辑
                if (TextUtils.isEmpty(username)) {
                    Toast.makeText(LoginActivity.this, "Please enter your username", Toast.LENGTH_SHORT).show();
                } else if (TextUtils.isEmpty(password)) {
                    Toast.makeText(LoginActivity.this, "Please enter your password", Toast.LENGTH_SHORT).show();
                } else {
                    // 注册成功
                    Toast.makeText(LoginActivity.this, "Register success", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

以上代码仅供参考，实际情况需要根据具体需求进行修改。