Question

我的应用程序有几个操作栏标签，这是其中一个片段。它应该显示有关电池的一些信息。导航应用程序一段时间后会出现错误。请解释导致问题的原因以及解决问题的方法

以下是LogCat的错误：

05-15 07:24:30.809: E/AndroidRuntime(25883): FATAL EXCEPTION: main
05-15 07:24:30.809: E/AndroidRuntime(25883): java.lang.RuntimeException: Error receiving broadcast Intent { act=android.intent.action.BATTERY_CHANGED flg=0x60000010 (has extras) } in com.example.mytaskmanager.Battery$1@4185ea78
05-15 07:24:30.809: E/AndroidRuntime(25883):     at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:755)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at android.os.Handler.handleCallback(Handler.java:605)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at android.os.Handler.dispatchMessage(Handler.java:92)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at android.os.Looper.loop(Looper.java:154)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at android.app.ActivityThread.main(ActivityThread.java:4624)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at java.lang.reflect.Method.invokeNative(Native Method)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at java.lang.reflect.Method.invoke(Method.java:511)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at dalvik.system.NativeStart.main(Native Method)
05-15 07:24:30.809: E/AndroidRuntime(25883): Caused by: java.lang.NullPointerException
05-15 07:24:30.809: E/AndroidRuntime(25883):     at com.example.mytaskmanager.Battery.setare(Battery.java:77)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at com.example.mytaskmanager.Battery$1.onReceive(Battery.java:120)
05-15 07:24:30.809: E/AndroidRuntime(25883):     at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:746)
05-15 07:24:30.809: E/AndroidRuntime(25883):     ... 9 more

和代码：

public class Battery extends Fragment {
    private TextView batteryInfo, memoryInfo, procent;
    int  health = 0, level=0, plugged=0, scale=0, status=0, temperature=0, voltage=0;
    String  technology = "";
    boolean present = false;
    ProgressBar pb;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View myFragmentView = inflater.inflate(R.layout.layout, container, false);
        return myFragmentView;
    }

    @Override
    public void onResume() {
        super.onResume();
        procent=(TextView)getActivity().findViewById(R.id.BatteryProc);
        batteryInfo=(TextView)getActivity().findViewById(R.id.textViewBatteryInfo);
        pb = (ProgressBar)getActivity().findViewById(R.id.progressbar);
        memoryInfo = (TextView)getActivity().findViewById(R.id.memory);
        setare();
        getMemInfo();

    }



    public void setare(){

        procent.setText("Level: " + level + "%");
        pb.setProgress(level);
        batteryInfo.setText(
                "Health: "+health+"\n"+
                "Plugged: "+plugged+"\n"+
                "Present: "+present+"\n"+
                "Scale: "+scale+"\n"+
                "Status: "+status+"\n"+
                "Technology: "+technology+"\n"+
                "Temperature: "+temperature+"\n"+
                "Voltage: "+voltage+"\n");

    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getActivity().registerReceiver(this.batteryInfoReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
     }

    private BroadcastReceiver batteryInfoReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            health= intent.getIntExtra(BatteryManager.EXTRA_HEALTH,0);
            level= intent.getIntExtra(BatteryManager.EXTRA_LEVEL,0);
            plugged= intent.getIntExtra(BatteryManager.EXTRA_PLUGGED,0);
            present= intent.getExtras().getBoolean(BatteryManager.EXTRA_PRESENT);
            scale= intent.getIntExtra(BatteryManager.EXTRA_SCALE,0);
            status= intent.getIntExtra(BatteryManager.EXTRA_STATUS,0);
            technology= intent.getExtras().getString(BatteryManager.EXTRA_TECHNOLOGY);
            temperature= intent.getIntExtra(BatteryManager.EXTRA_TEMPERATURE,0);
            voltage= intent.getIntExtra(BatteryManager.EXTRA_VOLTAGE,0);

            batteryInfo=(TextView)getActivity().findViewById(R.id.textViewBatteryInfo);
            pb = (ProgressBar)getActivity().findViewById(R.id.progressbar);
            memoryInfo = (TextView)getActivity().findViewById(R.id.memory);
            procent=(TextView)getActivity().findViewById(R.id.BatteryProc);

            setare();        
            getMemInfo();

        }
    };

Answer 1

您的View层次结构中的过程，batteryInfo视图在哪里？如果它们位于onCreateView中的R.layout.layout中，请将findViewByIds移动到onCreateView并使用myFragmentView而不是getActivity（）：例如：procent = (TextView) myFragmentView.findViewById(R.id.BatteryProc);

获取电池信息时出现Android错误（在片段中）

1 个答案: