วิธีดึงข้อมูลอุปกรณ์ (Device Info) ใน Android

การดึงข้อมูลเซลล์ (Cell Info) และข้อมูลอุปกรณ์ใน Android

ตัวอย่างสาธิตการใช้ TelephonyManager.getAllCellInfo() (API 17+) เพื่อดึงข้อมูลเซลล์ทावरทั้งหมดที่อุปกรณ์ตรวจพบ พร้อมข้อมูลอุปกรณ์จาก Build class

ขั้นตอนที่ 1: สร้างโปรเจกต์ใหม่

Android Studio → File → New Project

ขั้นตอนที่ 2: Layout XML (res/layout/activity_main.xml)

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

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/text"
            android:textSize="14sp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="16dp" />

    </ScrollView>

</LinearLayout>

ขั้นตอนที่ 3: AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="https://schemas.android.com/apk/res/android"
    package="com.example.myapplication">

    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application ...>
        <activity android:name=".MainActivity"> ... </activity>
    </application>
</manifest>

ขั้นตอนที่ 4: โค้ด Java (src/MainActivity.java)

package com.example.myapplication;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.RequiresApi;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.telephony.CellIdentity;
import android.telephony.CellInfo;
import android.telephony.CellInfoGsm;
import android.telephony.CellInfoLte;
import android.telephony.CellInfoNr;
import android.telephony.CellInfoWcdma;
import android.telephony.TelephonyManager;
import android.widget.TextView;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private static final int PERMISSION_REQUEST_CODE = 100;
    TextView textView;
    TelephonyManager telephonyManager;

    @RequiresApi(api = Build.VERSION_CODES.P)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = findViewById(R.id.text);
        telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        checkPermissionAndFetch();
    }

    private void checkPermissionAndFetch() {
        String[] perms = {Manifest.permission.READ_PHONE_STATE, Manifest.permission.ACCESS_FINE_LOCATION};
        boolean granted = true;
        for (String p : perms) {
            if (ActivityCompat.checkSelfPermission(this, p) != PackageManager.PERMISSION_GRANTED) {
                granted = false; break;
            }
        }
        if (!granted) {
            ActivityCompat.requestPermissions(this, perms, PERMISSION_REQUEST_CODE);
        } else {
            fetchAllDeviceInfo();
        }
    }

    @RequiresApi(api = Build.VERSION_CODES.P)
    private void fetchAllDeviceInfo() {
        StringBuilder sb = new StringBuilder();

        // === 1. Device Info (Build class - ไม่ต้อง Permission) ===
        sb.append("=== DEVICE INFO (Build) ===\n");
        sb.append("Brand: ").append(Build.BRAND).append("\n");
        sb.append("Manufacturer: ").append(Build.MANUFACTURER).append("\n");
        sb.append("Model: ").append(Build.MODEL).append("\n");
        sb.append("Device: ").append(Build.DEVICE).append("\n");
        sb.append("Product: ").append(Build.PRODUCT).append("\n");
        sb.append("Hardware: ").append(Build.HARDWARE).append("\n");
        sb.append("Board: ").append(Build.BOARD).append("\n");
        sb.append("Bootloader: ").append(Build.BOOTLOADER).append("\n");
        sb.append("Fingerprint: ").append(Build.FINGERPRINT).append("\n");
        sb.append("API Level: ").append(Build.VERSION.SDK_INT).append(" (").append(Build.VERSION.RELEASE).append(")\n");
        sb.append("Security Patch: ").append(Build.VERSION.SECURITY_PATCH).append("\n\n");

        // === 2. Telephony Info ===
        sb.append("=== TELEPHONY INFO ===\n");
        sb.append("Phone Type: ").append(getPhoneTypeName(telephonyManager.getPhoneType())).append("\n");
        sb.append("Network Type: ").append(getNetworkTypeName(telephonyManager.getNetworkType())).append("\n");
        sb.append("Network Operator: ").append(telephonyManager.getNetworkOperatorName()).append("\n");
        sb.append("Network Operator (Numeric): ").append(telephonyManager.getNetworkOperator()).append("\n");
        sb.append("Sim Operator: ").append(telephonyManager.getSimOperatorName()).append("\n");
        sb.append("Sim Country ISO: ").append(telephonyManager.getSimCountryIso()).append("\n");
        sb.append("Data State: ").append(getDataStateName(telephonyManager.getDataState())).append("\n");
        sb.append("Call State: ").append(getCallStateName(telephonyManager.getCallState())).append("\n");
        sb.append("SMS Capable: ").append(telephonyManager.isSmsCapable()).append("\n");
        sb.append("World Phone: ").append(telephonyManager.isWorldPhone()).append("\n");
        sb.append("Voice+Data Concurrent: ").append(telephonyManager.isConcurrentVoiceAndDataSupported()).append("\n\n");

        // === 3. Cell Info (All Cells) ===
        sb.append("=== CELL INFO (getAllCellInfo) ===\n");
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            List<CellInfo> cellInfoList = telephonyManager.getAllCellInfo();
            if (cellInfoList != null && !cellInfoList.isEmpty()) {
                for (int i = 0; i < cellInfoList.size(); i++) {
                    sb.append("Cell ").append(i + 1).append(": ").append(parseCellInfo(cellInfoList.get(i))).append("\n");
                }
            } else {
                sb.append("No cell info available (Airplane mode? No SIM?)\n");
            }
        } else {
            sb.append("Need ACCESS_FINE_LOCATION permission\n");
        }

        textView.setText(sb.toString());
    }

    private String parseCellInfo(CellInfo cellInfo) {
        CellIdentity identity = cellInfo.getCellIdentity();
        android.telephony.CellSignalStrength signal = cellInfo.getCellSignalStrength();
        StringBuilder sb = new StringBuilder();

        if (identity instanceof CellIdentityGsm) {
            CellIdentityGsm gsm = (CellIdentityGsm) identity;
            sb.append("GSM | MCC:").append(gsm.getMcc())
              .append(" MNC:").append(gsm.getMnc())
              .append(" CID:").append(gsm.getCid())
              .append(" LAC:").append(gsm.getLac())
              .append(" ARFCN:").append(gsm.getArfcn())
              .append(" RSSI:").append(signal.getAsuLevel()).append(" ASU (").append(signal.getDbm()).append(" dBm)");
        } else if (identity instanceof CellIdentityWcdma) {
            CellIdentityWcdma wcdma = (CellIdentityWcdma) identity;
            sb.append("WCDMA | MCC:").append(wcdma.getMcc())
              .append(" MNC:").append(wcdma.getMnc())
              .append(" CID:").append(wcdma.getCid())
              .append(" LAC:").append(wcdma.getLac())
              .append(" PSC:").append(wcdma.getPsc())
              .append(" RSCP:").append(signal.getDbm()).append(" dBm");
        } else if (identity instanceof CellIdentityLte) {
            CellIdentityLte lte = (CellIdentityLte) identity;
            sb.append("LTE | MCC:").append(lte.getMcc())
              .append(" MNC:").append(lte.getMnc())
              .append(" CI:").append(lte.getCi())
              .append(" TAC:").append(lte.getTac())
              .append(" PCI:").append(lte.getPci())
              .append(" EARFCN:").append(lte.getEarfcn())
              .append(" Band:").append(lte.getBand())
              .append(" RSRP:").append(signal.getDbm()).append(" dBm");
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q && identity instanceof CellIdentityNr) {
            CellIdentityNr nr = (CellIdentityNr) identity;
            sb.append("5G NR | MCC:").append(nr.getMcc())
              .append(" MNC:").append(nr.getMnc())
              .append(" NCI:").append(nr.getNci())
              .append(" PCI:").append(nr.getPci())
              .append(" NR-ARFCN:").append(nr.getNrarfcn())
              .append(" Band:").append(nr.getBand())
              .append(" RSRP:").append(signal.getDbm()).append(" dBm");
        } else {
            sb.append("Unknown Cell Type: ").append(cellInfo.getClass().getSimpleName());
        }
        return sb.toString();
    }

    // Helper methods (เหมือนบทความก่อนหน้า)
    private String getPhoneTypeName(int type) { ... }
    private String getNetworkTypeName(int type) { ... }
    private String getDataStateName(int state) { ... }
    private String getCallStateName(int state) { ... }

    @RequiresApi(api = Build.VERSION_CODES.P)
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == PERMISSION_REQUEST_CODE) {
            boolean granted = grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED;
            if (granted) fetchAllDeviceInfo();
            else textView.setText("Permission denied");
        }
    }
}

การทดสอบ

รันแอป อนุญาต Permission (Phone State + Location) จะแสดงข้อมูลอุปกรณ์ครบถ้วน + Cell Info ทุกเซลล์ที่ตรวจพบ

ข้อมูลที่ได้จาก getAllCellInfo()

• Serving Cell: เซลล์ที่เชื่อมต่ออยู่ (Primary)
• Neighbor Cells: เซลล์รอบข้าง (สำหรับ Handover)
• รองรับ: GSM, WCDMA, LTE, 5G NR (API 29+)
• แต่ละ Cell มี: Identity (MCC, MNC, CID/PCI, TAC, Band) + Signal Strength

Cell Identity Fields คำอธิบาย

Signal Strength Metrics

• getAsuLevel() - Arbitrary Strength Unit (0-31 GSM, 0-97 LTE)
• getDbm() - dBm (Negative values, closer to 0 = stronger)
• getLevel() - 0-4 (Signal Bar Level)
• LTE: RSRP (dBm), RSRQ (dB), RSSNR (dB), CQI (0-15)
• 5G: RSRP, RSRQ, SINR

กรณีการใช้งาน (Use Cases)

• Network Diagnostic Tools
• Signal Strength Mapping / Coverage Maps
• Carrier Aggregation Detection (Multiple LTE Cells)
• Handover Analysis
• IoT Device Network Selection
• Emergency Location (Cell ID based)

Best Practices

1. ขอ ACCESS_FINE_LOCATION (จำเป็นสำหรับ getAllCellInfo() API 28+)
2. จัดการ null/empty list (Airplane mode, No SIM)
3. ใช้ PhoneStateListener.LISTEN_CELL_INFO สำหรับ Real-time Updates
4. Dual SIM: ใช้ createForSubscriptionId() ต่อ Subscription
5. Cache ผลลัพธ์ - การสแกน Cell ใช้ Battery มาก

Real-time Cell Info Listener (API 17+)

telephonyManager.listen(new PhoneStateListener() {
    @Override
    public void onCellInfoChanged(List<CellInfo> cellInfoList) {
        super.onCellInfoChanged(cellInfoList);
        // อัปเดต UI ด้วย cellInfoList ใหม่
        runOnUiThread(() -> updateCellInfoUI(cellInfoList));
    }
}, PhoneStateListener.LISTEN_CELL_INFO);