片段类内部的java ProgressBar导致setMax方法出现NullPointerException？
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.analogin_fragment,
container, false);
AITVVOLT0 = (TextView) rootView.findViewById(R.id.aintvvolt0);
AITVVOLT1 = (TextView) rootView.findViewById(R.id.aintvvolt1);
AITVVOLT2 = (TextView) rootView.findViewById(R.id.aintvvolt2);
AITVVOLT3 = (TextView) rootView.findViewById(R.id.aintvvolt3);
AITVVOLT4 = (TextView) rootView.findViewById(R.id.aintvvolt4);
AITVVOLT5 = (TextView) rootView.findViewById(R.id.aintvvolt5);
AIVOLTBAR0 = (ProgressBar) rootView.findViewById(R.id.aintvvoltbar0);
AIVOLTBAR0 = (ProgressBar) rootView.findViewById(R.id.aintvvoltbar1);
AIVOLTBAR0 = (ProgressBar) rootView.findViewById(R.id.aintvvoltbar2);
AIVOLTBAR0 = (ProgressBar) rootView.findViewById(R.id.aintvvoltbar3);
AIVOLTBAR0 = (ProgressBar) rootView.findViewById(R.id.aintvvoltbar4);
AIVOLTBAR0 = (ProgressBar) rootView.findViewById(R.id.aintvvoltbar5);
AIVOLTBAR0.setMax(100);
AIVOLTBAR1.setMax(100);
AIVOLTBAR2.setMax(100);
AIVOLTBAR3.setMax(100);
AIVOLTBAR4.setMax(100);
AIVOLTBAR5.setMax(100);
AIVOLTBAR0.setProgress(0);
AIVOLTBAR1.setProgress(0);
AIVOLTBAR2.setProgress(0);
AIVOLTBAR3.setProgress(0);
AIVOLTBAR4.setProgress(0);
AIVOLTBAR5.setProgress(0);
return rootView;
}
艾沃尔特酒吧。setMax（）；方法会导致NullPointerException，但ProgressBars不是null（使用日志测试，并注释掉setMax会导致程序工作）
Logcat：
08-20 16:23:18.409: E/AndroidRuntime(1332): Process: com.nanospark.安卓app, PID: 1332
08-20 16:23:18.409: E/AndroidRuntime(1332): java.lang.NullPointerException
08-20 16:23:18.409: E/AndroidRuntime(1332): at com.nanospark.安卓app.MainActivity$AnalogInputFragment.onCreateView(MainActivity.java:218)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:938)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1115)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1478)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:446)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.os.Handler.handleCallback(Handler.java:733)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.os.Handler.dispatchMessage(Handler.java:95)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.os.Looper.loop(Looper.java:136)
08-20 16:23:18.409: E/AndroidRuntime(1332): at 安卓.app.ActivityThread.main(ActivityThread.java:5017)
08-20 16:23:18.409: E/AndroidRuntime(1332): at java.lang.reflect.Method.invokeNative(Native Method)
08-20 16:23:18.409: E/AndroidRuntime(1332): at java.lang.reflect.Method.invoke(Method.java:515)
08-20 16:23:18.409: E/AndroidRuntime(1332): at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
08-20 16:23:18.409: E/AndroidRuntime(1332): at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:595)
08-20 16:23:18.409: E/AndroidRuntime(1332): at dalvik.system.NativeStart.main(Native Method)
08-20 16:27:27.557: E/BluetoothAdapter(1387): Bluetooth binder is null
08-20 16:27:27.853: E/OpenGLRenderer(1387): Getting MAX_TEXTURE_SIZE from GradienCache
08-20 16:27:27.853: E/OpenGLRenderer(1387): MAX_TEXTURE_SIZE: 16384
08-20 16:27:27.865: E/OpenGLRenderer(1387): Getting MAX_TEXTURE_SIZE from Caches::initConstraints()
08-20 16:27:27.869: E/OpenGLRenderer(1387): MAX_TEXTURE_SIZE: 16384
08-20 16:27:28.409: E/AndroidRuntime(1387): FATAL EXCEPTION: main
08-20 16:27:28.409: E/AndroidRuntime(1387): Process: com.nanospark.安卓app, PID: 1387
08-20 16:27:28.409: E/AndroidRuntime(1387): java.lang.NullPointerException
08-20 16:27:28.409: E/AndroidRuntime(1387): at com.nanospark.安卓app.MainActivity$AnalogInputFragment.onCreateView(MainActivity.java:223)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:938)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1115)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1478)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:446)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.os.Handler.handleCallback(Handler.java:733)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.os.Handler.dispatchMessage(Handler.java:95)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.os.Looper.loop(Looper.java:136)
08-20 16:27:28.409: E/AndroidRuntime(1387): at 安卓.app.ActivityThread.main(ActivityThread.java:5017)
08-20 16:27:28.409: E/AndroidRuntime(1387): at java.lang.reflect.Method.invokeNative(Native Method)
08-20 16:27:28.409: E/AndroidRuntime(1387): at java.lang.reflect.Method.invoke(Method.java:515)
08-20 16:27:28.409: E/AndroidRuntime(1387): at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
08-20 16:27:28.409: E/AndroidRuntime(1387): at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:595)
08-20 16:27:28.409: E/AndroidRuntime(1387): at dalvik.system.NativeStart.main(Native Method)
# 1 楼答案
问题是你有一些打字错误。您多次设置
AIVOLTBAR0，而不是单独设置每个进度条：相反，它需要这样：