我刚开始学习 Android 开发,想知道如何获取用户的信号强度。下面的代码可以获得 GSM 网络的 Dbm:
TelephonyManager telephonyManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
// Get GSM Signal Strength (Dbm)
CellInfoGsm GSM = (CellInfoGsm)telephonyManager.getAllCellInfo().get(0);
CellSignalStrengthGsm cellSignalStrengthGsm = GSM.getCellSignalStrength();
signalStrength = cellSignalStrengthGsm.getDbm();
然而,我希望能够获取任何类型网络的信号强度。不管是GSM、LTE、CDMA还是WCDMA网络。我已经查看了电信文档,但是我不知道如何操作。我尝试使用与上面相同的代码,只是用Lte代替Gsm,但这导致我的模拟器崩溃。
任何帮助都将不胜感激。
更新并添加了下面答案中的监听器,但现在只要运行app就会崩溃。这是日志文件。
05-26 11:25:21.140: D/AndroidRuntime(921): Shutting down VM
05-26 11:25:21.140: W/dalvikvm(921): threadid=1: thread exiting with uncaught exception (group=0xb3aecba8)
05-26 11:25:21.170: E/AndroidRuntime(921): FATAL EXCEPTION: main
05-26 11:25:21.170: E/AndroidRuntime(921): Process: com.example.androidcellinfo, PID: 921
05-26 11:25:21.170: E/AndroidRuntime(921): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.androidcellinfo/com.example.androidcellinfo.MainActivity}: java.lang.NullPointerException
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.os.Handler.dispatchMessage(Handler.java:102)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.os.Looper.loop(Looper.java:136)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.ActivityThread.main(ActivityThread.java:5017)
05-26 11:25:21.170: E/AndroidRuntime(921): at java.lang.reflect.Method.invokeNative(Native Method)
05-26 11:25:21.170: E/AndroidRuntime(921): at java.lang.reflect.Method.invoke(Method.java:515)
05-26 11:25:21.170: E/AndroidRuntime(921): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-26 11:25:21.170: E/AndroidRuntime(921): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-26 11:25:21.170: E/AndroidRuntime(921): at dalvik.system.NativeStart.main(Native Method)
05-26 11:25:21.170: E/AndroidRuntime(921): Caused by: java.lang.NullPointerException
05-26 11:25:21.170: E/AndroidRuntime(921): at com.example.androidcellinfo.CellInfo.<init>(CellInfo.java:74)
05-26 11:25:21.170: E/AndroidRuntime(921): at com.example.androidcellinfo.MainActivity.onCreate(MainActivity.java:28)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.Activity.performCreate(Activity.java:5231)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
05-26 11:25:21.170: E/AndroidRuntime(921): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
05-26 11:25:21.170: E/AndroidRuntime(921): ... 11 more
05-26 11:25:25.090: I/Process(921): Sending signal. PID: 921 SIG: 9
以下是第74行(CellInfo)的代码:
![Code Snippet 1](https://istack.dev59.com/xueSu.webp)
![Code Snippet 2](https://istack.dev59.com/v7fRx.webp)