我安装了一些Android Studio更新之前,我的android应用程序运行平稳,并要求我在安装更新后升级gradle等。Android Studio - 应用程序已停止,但0代码错误
之后,Android Studio要求我更新我的Android模拟器(Emulator Nexus 5X API 24 Android v7.0),因为我做了所有这些更改,当我单击运行时,我的应用程序无法打开。但要记住它没有作弄错误,当我调试等
从Android的监视错误消息是:
08-13 14:07:30.735 3889-3889/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.smartlegal.law.freeman.smartlegal, PID: 3889
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.smartlegal.law.freeman.smartlegal/com.smartlegal.law.freeman.smartlegal.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at com.smartlegal.law.freeman.smartlegal.MainActivity.onCreate(MainActivity.java:39)
at android.app.Activity.performCreate(Activity.java:6662)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
08-13 14:07:30.744 3889-3896/? W/art: Suspending all threads took: 5.874ms
请提供[mcve]。这将包括'com.smartlegal.law.freeman.smartlegal.MainActivity'的'onCreate()'的源代码以及由该方法加载的任何布局资源。 – CommonsWare