安卓studio编写登录注册功能

实现登录注册功能需要用到安卓开发中的布局、控件、数据库和网络通信等知识。以下是一个简单的登录注册示例代码，供参考：

1. 布局文件activity_main.xml

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

    <EditText
        android:id="@+id/username"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入用户名" />

    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入密码"
        android:inputType="textPassword" />

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

    <TextView
        android:id="@+id/register"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="注册账号"
        android:gravity="center"
        android:textColor="@color/colorAccent" />

</LinearLayout>

2. 注册页面布局文件activity_register.xml

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

    <EditText
        android:id="@+id/username"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入用户名" />

    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入密码"
        android:inputType="textPassword" />

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

</LinearLayout>

3. MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private EditText usernameEditText, passwordEditText;
    private Button loginButton;
    private TextView registerTextView;

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

        usernameEditText = findViewById(R.id.username);
        passwordEditText = findViewById(R.id.password);
        loginButton = findViewById(R.id.login);
        registerTextView = findViewById(R.id.register);

        loginButton.setOnClickListener(this);
        registerTextView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.login:
                String username = usernameEditText.getText().toString().trim();
                String password = passwordEditText.getText().toString().trim();
                if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
                    Toast.makeText(this, "用户名或密码不能为空", Toast.LENGTH_SHORT).show();
                } else {
                    // 调用登录接口
                    // TODO
                }
                break;
            case R.id.register:
                Intent intent = new Intent(MainActivity.this, RegisterActivity.class);
                startActivity(intent);
                break;
            default:
                break;
        }
    }
}

4. RegisterActivity.java

public class RegisterActivity extends AppCompatActivity implements View.OnClickListener {
    private EditText usernameEditText, passwordEditText;
    private Button registerButton;

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

        usernameEditText = findViewById(R.id.username);
        passwordEditText = findViewById(R.id.password);
        registerButton = findViewById(R.id.register);

        registerButton.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.register:
                String username = usernameEditText.getText().toString().trim();
                String password = passwordEditText.getText().toString().trim();
                if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
                    Toast.makeText(this, "用户名或密码不能为空", Toast.LENGTH_SHORT).show();
                } else {
                    // 调用注册接口
                    // TODO
                }
                break;
            default:
                break;
        }
    }
}

5. 网络通信部分（使用OkHttp库）

public class HttpUtil {
    private static final String TAG = "HttpUtil";

    private static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");

    public static void sendOkHttpRequest(final String address, final String json, final Callback callback) {
        OkHttpClient client = new OkHttpClient();
        RequestBody requestBody = RequestBody.create(JSON, json);
        final Request request = new Request.Builder().url(address).post(requestBody).build();
        client.newCall(request).enqueue(callback);
    }
}

6. 数据库部分（使用LitePal库）

先在build.gradle中添加以下依赖：

dependencies {
    implementation 'org.litepal.android:core:3.0.0'
}

创建User实体类：

public class User extends LitePalSupport {
    private String username;
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

7. 登录接口示例代码

private void login(String username, String password) {
    JSONObject jsonObject = new JSONObject();
    try {
        jsonObject.put("username", username);
        jsonObject.put("password", password);
    } catch (JSONException e) {
        e.printStackTrace();
    }
    String json = jsonObject.toString();
    HttpUtil.sendOkHttpRequest("http://www.example.com/login", json, new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {
            Log.d(TAG, "onFailure: " + e.getMessage());
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(MainActivity.this, "登录失败，请检查网络连接", Toast.LENGTH_SHORT).show();
                }
            });
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String responseData = response.body().string();
            Log.d(TAG, "onResponse: " + responseData);
            try {
                JSONObject jsonObject = new JSONObject(responseData);
                int code = jsonObject.getInt("code");
                if (code == 1) {
                    // 登录成功，保存用户信息
                    User user = new User();
                    user.setUsername(username);
                    user.setPassword(password);
                    user.save();

                    Intent intent = new Intent(MainActivity.this, HomeActivity.class);
                    startActivity(intent);
                    finish();
                } else {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(MainActivity.this, "用户名或密码错误", Toast.LENGTH_SHORT).show();
                        }
                    });
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    });
}

8. 注册接口示例代码

private void register(String username, String password) {
    JSONObject jsonObject = new JSONObject();
    try {
        jsonObject.put("username", username);
        jsonObject.put("password", password);
    } catch (JSONException e) {
        e.printStackTrace();
    }
    String json = jsonObject.toString();
    HttpUtil.sendOkHttpRequest("http://www.example.com/register", json, new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {
            Log.d(TAG, "onFailure: " + e.getMessage());
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(RegisterActivity.this, "注册失败，请检查网络连接", Toast.LENGTH_SHORT).show();
                }
            });
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            String responseData = response.body().string();
            Log.d(TAG, "onResponse: " + responseData);
            try {
                JSONObject jsonObject = new JSONObject(responseData);
                int code = jsonObject.getInt("code");
                if (code == 1) {
                    // 注册成功，保存用户信息
                    User user = new User();
                    user.setUsername(username);
                    user.setPassword(password);
                    user.save();

                    Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);
                    startActivity(intent);
                    finish();
                } else {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(RegisterActivity.this, "注册失败，请重新尝试", Toast.LENGTH_SHORT).show();
                        }
                    });
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    });
}

注意：以上代码仅供参考，具体实现方式可能因项目需求和开发细节而有所不同，还需根据具体情况进行调整和完善。