Android中，可以使用HttpURLConnection来登录到aspx网站。下面是一个使用HttpURLConnection进行登录的示例代码：

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class LoginHelper {
    private static final String LOGIN_URL = "http://example.com/login.aspx";
    private static final String USERNAME = "username";
    private static final String PASSWORD = "password";

    public static void main(String[] args) {
        try {
            loginToWebsite();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void loginToWebsite() throws IOException {
        URL url = new URL(LOGIN_URL);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        // Enable output and input streams
        connection.setDoOutput(true);
        connection.setDoInput(true);

        // Set request method to POST
        connection.setRequestMethod("POST");

        // Set request parameters
        String postData = "username=" + URLEncoder.encode(USERNAME, "UTF-8") +
                "&password=" + URLEncoder.encode(PASSWORD, "UTF-8");

        // Send POST data
        DataOutputStream outputStream = new DataOutputStream(connection.getOutputStream());
        outputStream.writeBytes(postData);
        outputStream.flush();
        outputStream.close();

        // Get response code
        int responseCode = connection.getResponseCode();

        if (responseCode == HttpURLConnection.HTTP_OK) {
            // Read response
            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            StringBuilder response = new StringBuilder();

            while ((line = reader.readLine()) != null) {
                response.append(line);
            }

            reader.close();

            // Handle login success
            System.out.println("Login successful. Response: " + response.toString());
        } else {
            // Handle login failure
            System.out.println("Login failed. Response code: " + responseCode);
        }

        // Close connection
        connection.disconnect();
    }
}

在代码中，首先创建一个URL对象，然后使用该URL对象创建HttpURLConnection对象。接下来，我们启用输出和输入流，设置请求方法为POST，并设置请求参数。然后，我们发送POST数据，并获取响应码。如果响应码为HTTP_OK（200），则读取响应数据并处理登录成功。否则，处理登录失败。

请注意，此示例中的URL、用户名和密码是示例数据，请根据实际情况修改。