java - 短信接收器仅在打开某个 Activity 时才起作用

Question

我创建了一个应用程序，它使用 BroadcastReceiver 类在应用程序内接收 SMS 消息，以便在收到特定短信时更改和控制应用程序内的不同内容。我最近向应用程序添加了一个新 Activity ，现在的问题是，如果应用程序收到一条短信，它将崩溃，除非新 Activity 已经启动。谁能想到为什么会这样？谢谢

这是我的崩溃错误日志:

 07-31 15:51:50.135: E/AndroidRuntime(779): FATAL EXCEPTION: main
 07-31 15:51:50.135: E/AndroidRuntime(779): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.becatech.gsmzonecontroller/com.becatech.gsmzonecontroller.MainActivity}: java.lang.NullPointerException
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.ActivityThread.access$700(ActivityThread.java:140)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.os.Handler.dispatchMessage(Handler.java:99)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.os.Looper.loop(Looper.java:137)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.ActivityThread.main(ActivityThread.java:4921)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at java.lang.reflect.Method.invokeNative(Native Method)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at java.lang.reflect.Method.invoke(Method.java:511)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at dalvik.system.NativeStart.main(Native Method)
 07-31 15:51:50.135: E/AndroidRuntime(779): Caused by: java.lang.NullPointerException
 07-31 15:51:50.135: E/AndroidRuntime(779):     at com.becatech.gsmzonecontroller.MainActivity.onCreate(MainActivity.java:66)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.Activity.performCreate(Activity.java:5206)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
 07-31 15:51:50.135: E/AndroidRuntime(779):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)

Answer 1

在主 Activity 的第 66 行有一个 nullPointerException