Question

我在Android上遇到问题。我想知道设备是否连接到GSM网络，因此它可以发送短信。

我尝试了两种方式，它以同样的方式结束。在Moto G 4G上我能够确定它是否具有访问权限。在Redmi Note 4上，它总是返回false。

第一个：

public static boolean hasCellularAccess(Context context) {
    TelephonyManager telephonyManager = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);

    if(telephonyManager == null || telephonyManager.getAllCellInfo() == null || telephonyManager.getAllCellInfo().size() == 0){
        return false;
    }

    if (telephonyManager.getAllCellInfo().get(0) instanceof CellInfoLte){
        CellInfoLte cellInfoLte = (CellInfoLte)telephonyManager.getAllCellInfo().get(0);
        CellSignalStrength cellSignalStrengthGsm = cellInfoLte.getCellSignalStrength();
        return cellSignalStrengthGsm.getLevel() > 0;
    }

    CellInfoGsm cellinfogsm = (CellInfoGsm) telephonyManager.getAllCellInfo().get(0);
    CellSignalStrength cellSignalStrengthGsm = cellinfogsm.getCellSignalStrength();
    return cellSignalStrengthGsm.getLevel() > 0;
}

第二个：

public class CustomPhoneListener extends PhoneStateListener {
private static final String TAG = "PhoneListener";

@Override
public void onSignalStrengthsChanged(SignalStrength signalStrength) {
    super.onSignalStrengthsChanged(signalStrength);
    Log.i(TAG, "onSignalStrengthsChanged: " + signalStrength);
    if (signalStrength.isGsm()) {
        Log.i(TAG, "onSignalStrengthsChanged: getGsmSignalStrength "
                + signalStrength.getGsmSignalStrength() + signalStrength);
    }
    try {

        Method[] methods = android.telephony.SignalStrength.class
                .getMethods();
        for (Method mthd : methods) {
            if (mthd.getName().equals("getLteSignalStrength")) {
                Log.i(TAG,
                        "onSignalStrengthsChanged: " + mthd.getName() + " "
                                + mthd.invoke(signalStrength));
            }
        }
    } catch (SecurityException | IllegalArgumentException | InvocationTargetException | IllegalAccessException e) {
        e.printStackTrace();
    }

}}

在Redmi上我有：

SignalStrength：0 48 -120 -160 -7 0 -1 99 -93 -6 282 2147483647   gsm | lte 1 1 1

==＆GT;值99未知

在Moto上：

SignalStrength：99 0 -120 -160 -120 -1 -1 18 -109 -8 116   2147483647 2147483647 gsm | lte 0 -108 -1 false 0 0 0 0 2 99 99 99 4

==＆GT; 0到31之间的值是好的

之前有人遇到过这个问题并解决了吗？我已经读过一些三星Galaxy也存在这个问题。

谢谢！

Answer 1

有效！

所以这是我最后的工作，它的确有效。如果手机的正常运行时间值很长，那么API似乎会返回错误值。

public static boolean hasCellularAccess(Context context) {
    TelephonyManager telephonyManager = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);
    if(telephonyManager == null || telephonyManager.getAllCellInfo() == null || telephonyManager.getAllCellInfo().size() == 0){
        return false;
    }

    if (telephonyManager.getAllCellInfo().get(0) instanceof CellInfoLte){
        CellInfoLte cellInfoLte = (CellInfoLte)telephonyManager.getAllCellInfo().get(0);
        CellSignalStrength cellSignalStrengthGsm = cellInfoLte.getCellSignalStrength();
        return cellSignalStrengthGsm.getLevel() > 0;
    }

    if(telephonyManager.getAllCellInfo().get(0) instanceof CellInfoGsm){
        CellInfoGsm cellinfogsm = (CellInfoGsm) telephonyManager.getAllCellInfo().get(0);
        CellSignalStrength cellSignalStrengthGsm = cellinfogsm.getCellSignalStrength();
        return cellSignalStrengthGsm.getLevel() > 0;
    }else {
        CellInfoWcdma cellinfogsm = (CellInfoWcdma) telephonyManager.getAllCellInfo().get(0);
        CellSignalStrength cellSignalStrengthGsm = cellinfogsm.getCellSignalStrength();
        return cellSignalStrengthGsm.getLevel() > 0;
    }
}

PhoneStateListener Android错误值

1 个答案: