安卓应用中GSM信号强度测量总是显示为0

Question

信号强度一直显示为0

此代码运行无误，但信号强度始终显示为0。我尝试在模拟器和我的安卓设备上运行此代码，但都显示信号强度为0。

请详细说明如何获取我的移动网络的正确信号强度，如果可能的话，还要说明获取其他网络区域的信号强度的代码。

MainActivity.java

 package com.example.termproject;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.View;
 import android.app.Activity;
 import android.telephony.PhoneStateListener;
 import android.telephony.SignalStrength;
 import android.telephony.TelephonyManager;
 import android.content.Context;
 import android.widget.Toast;

 public class MainActivity extends Activity 
 {
    TelephonyManager Tel;
    MyPhoneStateListener MyListener;
    private int signal;

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

     }

     @Override
               public boolean onCreateOptionsMenu(Menu menu) 
     {
         getMenuInflater().inflate(R.menu.activity_main, menu);
         return true;
     }
     class MyPhoneStateListener extends PhoneStateListener
     {
       int signal;
       @Override
       public void onSignalStrengthsChanged(SignalStrength signalStrength)
       {
          super.onSignalStrengthsChanged(signalStrength);
          signal = signalStrength.getGsmSignalStrength();
       }
     }
     public void myaction(View v)
     {
        MyListener = new MyPhoneStateListener();
         Tel = ( TelephonyManager )getSystemService(Context.TELEPHONY_SERVICE);
         Tel.listen(MyListener ,PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
         Toast.makeText(getApplicationContext(), "GSM signal strength is " +    String.valueOf(this.signal), Toast.LENGTH_SHORT).show();
     }
 }

Manifest.xml

 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.example.termproject"
     android:versionCode="1"
     android:versionName="1.0" >

     <uses-sdk
         android:minSdkVersion="8"
         android:targetSdkVersion="15" />
     <!-- PERMISSIONS -->
    <uses-permission android:name="android.permission.CALL_PHONE"></uses-permission>
    <uses-permission android:name="android.permission.INTERNET"></uses-permission>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />


    <!-- LICENSE PERMISSIONS -->    
    <uses-permission android:name="com.android.vending.CHECK_LICENSE" />

    <!-- USES -->
    <uses-feature android:name="android.hardware.telephony"      android:required="false"/>
     <application
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
         <activity
             android:name=".MainActivity"
             android:label="@string/title_activity_main" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
     </application>

 </manifest>

activity_main.xml

 <RelativeLayout 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" >

     <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerHorizontal="true"
         android:layout_centerVertical="true"
         tools:context=".MainActivity" />
     <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@string/button_send" 
         android:onClick="myaction"/>


 </RelativeLayout>

- user1740542

Answer 1

这个线程似乎发现你的PhoneStateListener不正确。从你的问题来看，似乎你有一个CDMA设备，所以GSM始终会返回0。不确定模拟器的期望行为。

在Android中检测接收信号返回的时间

package com.piusvelte.wapdroid;

import static com.piusvelte.wapdroid.WapdroidService.PHONE_TYPE_CDMA;
import static android.telephony.NeighboringCellInfo.UNKNOWN_RSSI;
import android.telephony.CellLocation;
import android.telephony.PhoneStateListener;
import android.telephony.SignalStrength;
import android.telephony.TelephonyManager;

// PhoneStateListener for api >= 7
public class PhoneListenerApi7 extends PhoneStateListener {
        private WapdroidService mService;

        public PhoneListenerApi7(WapdroidService service) {
                mService = service;
        }

        public void onCellLocationChanged(CellLocation location) {
                // this also calls signalStrengthChanged, since signalStrengthChanged isn't reliable enough by itself
                mService.getCellInfo(location);
        }

        public void onSignalStrengthChanged(int asu) {
                // add cdma support, convert signal from gsm
                if ((mService.mTeleManager.getPhoneType() == TelephonyManager.PHONE_TYPE_GSM) || (mService.mTeleManager.getPhoneType() == PHONE_TYPE_CDMA)) mService.signalStrengthChanged((asu > 0) && (asu != UNKNOWN_RSSI) ? (2 * asu - 113) : asu);
                else mService.release();
        }

        public void onSignalStrengthsChanged(SignalStrength signalStrength) {
                if (mService.mTeleManager.getPhoneType() == TelephonyManager.PHONE_TYPE_GSM) {
                        int asu = signalStrength.getGsmSignalStrength();
                        mService.signalStrengthChanged((asu > 0) && (asu != UNKNOWN_RSSI) ? (2 * asu - 113) : asu);
                }
                else if (mService.mTeleManager.getPhoneType() == PHONE_TYPE_CDMA) mService.signalStrengthChanged(signalStrength.getCdmaDbm() < signalStrength.getEvdoDbm() ? signalStrength.getCdmaDbm() : signalStrength.getEvdoDbm());
                else mService.release();
        }
}

- ian.shaun.thomas