在Android中获取信号强度

Question

我希望在我点击API调用时得到设备的信号强度。我搜索了所有相关的主题，但我还没有成功。

所以我想获得信号强度

SignalStrength ss = null  ; // some initialization

int n = ss.getGsmSignalStrength();

但是在使用它时，很明显我会得到空指针异常，因为我已经将SignalStrength初始化为null。但我不知道如何初步化。

另外，我不想使用PhoneStateListener，因为只有在信号发生变化时才会触发它。

我使用下面的代码获得信号强度

TelephonyManager telephonyManager = (TelephonyManager)this.getSystemService(Context.TELEPHONY_SERVICE);
CellInfoGsm cellinfogsm = (CellInfoGsm)telephonyManager.getAllCellInfo().get(0);
CellSignalStrengthGsm cellSignalStrengthGsm = cellinfogsm.getCellSignalStrength();
cellSignalStrengthGsm.getDbm();

但是我不想使用CellSignalStrength，因为它只在API级别17中添加，并且在17级以下不起作用。我希望代码能够在API Level 7+上运行。

或者是否有其他方法，以便我可以在达到API调用时获得信号强度？

Answer 1

定义变量：

TelephonyManager mTelephonyManager;
MyPhoneStateListener mPhoneStatelistener;   
int mSignalStrength = 0;

然后将此类添加到您的代码中：

class MyPhoneStateListener extends PhoneStateListener {

     @Override
     public void onSignalStrengthsChanged(SignalStrength signalStrength) {
         super.onSignalStrengthsChanged(signalStrength);
         mSignalStrength = signalStrength.getGsmSignalStrength();
         mSignalStrength = (2 * mSignalStrength) - 113; // -> dBm           
     }
 }

并在您的onCreate方法中使用：

mPhoneStatelistener = new MyPhoneStateListener();
mTelephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
mTelephonyManager.listen(mPhoneStatelistener, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);

Answer 2

全球定义：

TelephonyManager telephonyManager;
myPhoneStateListener psListener;
TextView txtSignalStr;

onCreate方法：

@Override
protected void onCreate(final Bundle savedInstanceState) {
 txtSignalStr = (TextView)findViewById(R.id.signalStrength);
 psListener = new myPhoneStateListener();
 telephonyManager = (TelephonyManager)getActivity().getSystemService(Context.TELEPHONY_SERVICE);
 telephonyManager.listen(psListener,PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
}

创建myPhoneStateListener类：

public class myPhoneStateListener extends PhoneStateListener {
    public int signalStrengthValue;

    public void onSignalStrengthsChanged(SignalStrength signalStrength) {
        super.onSignalStrengthsChanged(signalStrength);
        if (signalStrength.isGsm()) {
            if (signalStrength.getGsmSignalStrength() != 99)
                signalStrengthValue = signalStrength.getGsmSignalStrength() * 2 - 113;
            else
                signalStrengthValue = signalStrength.getGsmSignalStrength();
        } else {
            signalStrengthValue = signalStrength.getCdmaDbm();
        }
        txtSignalStr.setText("Signal Strength : " + signalStrengthValue);
    }
}

Answer 3

public class PhoneCustomStateListener extends PhoneStateListener {

    public int signalSupport = 0;

    @Override
    public void onSignalStrengthsChanged(SignalStrength signalStrength) {
        super.onSignalStrengthsChanged(signalStrength);

        signalSupport = signalStrength.getGsmSignalStrength();
        Log.d(getClass().getCanonicalName(), "------ gsm signal --> " + signalSupport);

        if (signalSupport > 30) {
            Log.d(getClass().getCanonicalName(), "Signal GSM : Good");


        } else if (signalSupport > 20 && signalSupport < 30) {
            Log.d(getClass().getCanonicalName(), "Signal GSM : Avarage");


        } else if (signalSupport < 20 && signalSupport > 3) {
            Log.d(getClass().getCanonicalName(), "Signal GSM : Weak");


        } else if (signalSupport < 3) {
            Log.d(getClass().getCanonicalName(), "Signal GSM : Very weak");


        }
    }
}

Answer 4

我们不应该初始化signalstrength，而不是使用phonelistener并覆盖onSignalStrengthsChanged（SignalStrength signalStrength）方法。

例如，请查看以下代码段

class SamplePhoneStateListener extends PhoneStateListener {

        int signalStrength = 0;

        @Override
        public void onSignalStrengthsChanged(SignalStrength signalStrength) {
            super.onSignalStrengthsChanged(signalStrength);
            signalStrength = signalStrength.getGsmSignalStrength();
            //You can check the signal strength value here..
        }

    }

使用TelephonyManager对象你可以听上面的类就好

TelephonyManagerObject.listen(myListener,
            PhoneStateListener.LISTEN_SIGNAL_STRENGTHS)

Answer 5

这对我有用：

需要哪些服务：

ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);

如何收集指标：

public void startGatherMetrics() {
    NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
    if (networkInfo != null) {
        networkInfoStr = connectivityManager.getActiveNetworkInfo().toString();

        // gather Network Capabilities
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
            Network network = connectivityManager.getActiveNetwork();
            networkInfoStr += "; " + connectivityManager.getNetworkCapabilities(network).toString();
        }
    }
    Log.d("A_NETWORK_INFO", networkInfoStr);

    new Thread(new Runnable() {
        @Override
        public void run() {
            quitLooper = false;
            Looper.prepare();
            telephonyManager.listen(new PhoneStateListener() {
                @Override
                public void onSignalStrengthsChanged(SignalStrength signalStrength) {
                    super.onSignalStrengthsChanged(signalStrength);
                    Log.d("A_NETWORK_METRICS",
                        "Signal Strength (0-4 / dBm):" + getLevel(signalStrength) + " / "
                            + getDbm(signalStrength));

                    if (quitLooper)
                        Looper.myLooper().quit();
                }
            }, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);

            Looper.loop();
        }
    }).start();

}

public void stop() {
    quitLooper = true;
}

可以找到“getLevel（signalStrength）”和“getDbm（signalStrength）”here。

Answer 6

你没有实例化SignalStrength（可能你不能）。从应用程序代码。

您必须使用PhoneStateListener（子类），并实现onSignalStrengthsChanged：

http://developer.android.com/reference/android/telephony/PhoneStateListener.html#onSignalStrengthsChanged(android.telephony.SignalStrength)

将为您创建SignalStrength并将其传递到您的覆盖中。