Android 应用无法在设备上启动

Question

我正在用 android 开发一个应用程序，没有语法错误，但是当我在我的设备上部署我的应用程序时，它会出现以下 logcat 错误，如果有人可以帮我做我的 colg 项目，请帮助我

这些是以下 logcat 错误

            12-01 01:52:10.310: E/Trace(7853): error opening trace file: No such file or directory (2)
            12-01 01:52:10.310: D/ActivityThread(7853): setTargetHeapUtilization:0.75
            12-01 01:52:10.310: D/ActivityThread(7853): setTargetHeapIdealFree:8388608
            12-01 01:52:10.310: D/ActivityThread(7853): setTargetHeapConcurrentStart:2097152
            12-01 01:52:10.380: W/dalvikvm(7853): Refusing to reopen boot DEX '/system/framework/hwframework.jar'
            12-01 01:52:10.660: I/ActivityThread(7853): Pub com.aiou.fyp.provider: com.aiou.fyp.DataProvider
            12-01 01:52:11.070: W/dalvikvm(7853): threadid=1: thread exiting with uncaught exception (group=0x42022438)
            12-01 01:52:11.090: E/AndroidRuntime(7853): FATAL EXCEPTION: main
            12-01 01:52:11.090: E/AndroidRuntime(7853): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.aiou.fyp/com.aiou.fyp.MainActivity}: java.lang.NullPointerException
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2077)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2102)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.ActivityThread.access$600(ActivityThread.java:137)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.os.Handler.dispatchMessage(Handler.java:99)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.os.Looper.loop(Looper.java:137)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.ActivityThread.main(ActivityThread.java:4838)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at java.lang.reflect.Method.invokeNative(Native Method)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at java.lang.reflect.Method.invoke(Method.java:511)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:874)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at dalvik.system.NativeStart.main(Native Method)
            12-01 01:52:11.090: E/AndroidRuntime(7853): Caused by: java.lang.NullPointerException
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at com.aiou.fyp.MainActivity.onCreate(MainActivity.java:53)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.Activity.performCreate(Activity.java:5010)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2041)
            12-01 01:52:11.090: E/AndroidRuntime(7853):     ... 11 more

Answer 1

这通常发生在您忘记为您的布局组件之一充气但您试图在您的课程中使用它时。