Android Studio App 在新的 android 版本中不工作 [关闭]

Question

我创建了一个应用程序，它适用于较旧的 android 版本（最低 API 为 10），但是当我将它安装到其他设备（Android 4.4.2）时，该应用程序无法运行，我收到“应用程序无响应”屏幕。有什么帮助吗？

当我在菜单中选择一个位置时应用程序崩溃，这应该打开一个新活动...

还是谢谢

-编辑（错误消息）-

07-20 16:55:26.766  22142-22142/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.desenvolvimento.sqlteste, PID: 22142
android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.desenvolvimento.sqlteste/com.example.desenvolvimento.sqlteste.LoginActivity}; have you declared this activity in your AndroidManifest.xml?
        at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1852)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1552)
        at android.app.Activity.startActivityForResult(Activity.java:3746)
        at android.app.Activity.startActivityForResult(Activity.java:3707)
        at android.app.Activity.startActivity(Activity.java:4027)
        at android.app.Activity.startActivity(Activity.java:3989)
        at com.example.desenvolvimento.sqlteste.MainActivity$1.onItemClick(MainActivity.java:33)
        at android.widget.AdapterView.performItemClick(AdapterView.java:300)
        at android.widget.AbsListView.performItemClick(AbsListView.java:1143)
        at android.widget.AbsListView$PerformClick.run(AbsListView.java:3044)
        at android.widget.AbsListView.onTouchUp(AbsListView.java:3845)
        at android.widget.AbsListView.onTouchEvent(AbsListView.java:3617)
        at android.view.View.dispatchTouchEvent(View.java:8393)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2426)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2158)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2432)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2172)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2432)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2172)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2432)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2172)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2432)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2172)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2314)
        at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1692)
        at android.app.Activity.dispatchTouchEvent(Activity.java:2749)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2275)
        at android.view.View.dispatchPointerEvent(View.java:8583)
        at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4091)
        at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3957)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3509)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3562)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3528)
        at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3638)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3536)
        at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3695)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3509)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3562)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3528)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3536)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3509)
        at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5806)
        at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5745)
        at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5716)
        at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5896)
        at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:192)
        at android.os.MessageQueue.nativePollOnce(Native Method)
        at android.os.MessageQueue.next(MessageQueue.java:143)
        at android.os.Looper.loop(Looper.java:122)
        at android.app.ActivityThread.main(ActivityThread.java:5312)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.refl

-新的logcat

07-20 17:22:47.931  26650-26650/? E/AndroidRuntime? FATAL EXCEPTION: main
Process: com.example.desenvolvimento.sqlteste, PID: 26650
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.desenvolvimento.sqlteste/com.example.desenvolvimento.sqlteste.LoginActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2314)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2388)
        at android.app.ActivityThread.access$800(ActivityThread.java:148)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1292)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5312)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference
        at com.example.desenvolvimento.sqlteste.LoginActivity.setupActionBar(LoginActivity.java:120)
        at com.example.desenvolvimento.sqlteste.LoginActivity.onCreate(LoginActivity.java:35)
        at android.app.Activity.performCreate(Activity.java:5953)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1128)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2267)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2388)
            at android.app.ActivityThread.access$800(ActivityThread.java:148)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1292)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5312)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)

Answer 1

您需要在您的AndroidManifest.xml 中正确声明com.example.desenvolvimento.sqlteste.LoginActivity。由于您没有提供任何代码，因此这是要给出的最具体的答案。

请参阅Android Manifest documentation for activity。

此外，下一步是分析为什么LoginActivity 中的第 120 行会抛出 NullPointerException（根据您的异常日志）。

Answer 2

您必须将新活动添加到 AndroidManifest.xml 文件中