Java E/AndroidRuntime和xFE55;致命异常:主
当我测试我的应用程序时,在Android Studio控制台中出现以下错误:Java E/AndroidRuntime和xFE55;致命异常:主,java,android,android-studio,Java,Android,Android Studio,当我测试我的应用程序时,在Android Studio控制台中出现以下错误: 08-21 13:56:28.059 9637-9637/net.dominik.genpush E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: net.dominik.genpush, PID: 9637 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{net.do
08-21 13:56:28.059 9637-9637/net.dominik.genpush E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: net.dominik.genpush, PID: 9637
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{net.dominik.genpush/net.dominik.genpush.settings}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.app.Activity.findViewById(Activity.java:1884)
at net.dominik.genpush.settings.<init>(settings.java:23)
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1208)
at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2101)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
该应用程序也可以处理错误,但在一个应用程序中出现错误是不好的。
我已经在谷歌上搜索了很多,但我的java技能还远远不够,这是我第一次自创应用程序,原因是:java.lang.NullPointerException
Caused by: java.lang.NullPointerException
at android.app.Activity.findViewById(Activity.java:1884)
at net.dominik.genpush.settings.<init>(settings.java:23)
在android.app.Activity.findviewbyd(Activity.java:1884)上
在net.dominik.genpush.settings.(settings.java:23)
初始化“活动”settings
对象(可能是成员变量)时,调用findViewById()
太早了。你发布的代码没有显示这一点
实际上,只能在onCreate()或更高版本中调用活动函数
另外,将findViewById()
放在setContentView()
之后,这样它实际上可以返回null以外的内容。NullPointerException
在设置中。java
,第23行
您可以在logcat的原因中找到问题代码。显然,你的问题在于
at net.dominik.genpush.settings.<init>(settings.java:23)
net.dominik.genpush.settings.(settings.java:23)
at net.dominik.genpush.settings.<init>(settings.java:23)