java - 变量空指针异常

Question

我有存储静态主变量（应用程序的计算器）的主类（扩展应用程序）。所以在暂停应用程序（主页按钮或通话）后

06-21 00:43:14.916: E/AndroidRuntime(26676): FATAL EXCEPTION: AsyncTask #1
06-21 00:43:14.916: E/AndroidRuntime(26676): java.lang.RuntimeException: An error occured while executing doInBackground()
06-21 00:43:14.916: E/AndroidRuntime(26676):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.lang.Thread.run(Thread.java:856)
06-21 00:43:14.916: E/AndroidRuntime(26676): Caused by: java.lang.NullPointerException
06-21 00:43:14.916: E/AndroidRuntime(26676):    at com.AMain$CalcTask.doInBackground(AMain.java:106)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at ru.ps.horoscope.AMain$CalcTask.doInBackground(AMain.java:1)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
06-21 00:43:14.916: E/AndroidRuntime(26676):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
06-21 00:43:14.916: E/AndroidRuntime(26676):    ... 5 more

106 字符串：if (!_.calc.Calculated) CALCULATE_();

_ extends Application

如何解决？

       @Override
            protected Void doInBackground(Void... arg0) {
                // TODO Auto-generated method stub
if (!_.calc.Calculated) CALCULATE_();
                return null;
            }

Answer 1

_或calc为空。您需要发布代码才能获得比这更多的信息。