Java Android空指针异常MySimpleTreeAdapter
我在下面的代码中遇到了一些错误。我知道这是一个混乱的方式来处理事情。由于某种原因,我得到了一个空指针异常。堆栈跟踪指向第44行,即该行:Java Android空指针异常MySimpleTreeAdapter,java,android,Java,Android,我在下面的代码中遇到了一些错误。我知道这是一个混乱的方式来处理事情。由于某种原因,我得到了一个空指针异常。堆栈跟踪指向第44行,即该行: MySimpleCursorTreeAdapter mscta = new MySimpleCursorTreeAdapter( 代码: 堆栈跟踪: 09-11 14:33:09.365: ERROR/AndroidRuntime(161): Uncaught handler: thread main exiting due to uncaught exce
MySimpleCursorTreeAdapter mscta = new MySimpleCursorTreeAdapter(
代码:
堆栈跟踪:
09-11 14:33:09.365: ERROR/AndroidRuntime(161): Uncaught handler: thread main exiting due to uncaught exception
09-11 14:33:10.565: ERROR/AndroidRuntime(161): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.home.max/com.browse.max.Categories}: java.lang.NullPointerException
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.ActivityThread.startActivityNow(ActivityThread.java:2242)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:631)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.widget.TabHost.setCurrentTab(TabHost.java:317)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:127)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:346)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.View.performClick(View.java:2344)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.View.onTouchEvent(View.java:4133)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.View.dispatchTouchEvent(View.java:3672)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:850)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1712)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1202)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.Activity.dispatchTouchEvent(Activity.java:1987)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1696)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.view.ViewRoot.handleMessage(ViewRoot.java:1658)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.os.Handler.dispatchMessage(Handler.java:99)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.os.Looper.loop(Looper.java:123)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.ActivityThread.main(ActivityThread.java:4203)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at java.lang.reflect.Method.invokeNative(Native Method)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at java.lang.reflect.Method.invoke(Method.java:521)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at dalvik.system.NativeStart.main(Native Method)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): Caused by: java.lang.NullPointerException
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.browse.max.Categories$MySimpleCursorTreeAdapter.getChildrenCursor(Categories.java:69)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.widget.CursorTreeAdapter.getChildrenCursorHelper(CursorTreeAdapter.java:106)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.widget.SimpleCursorTreeAdapter.init(SimpleCursorTreeAdapter.java:172)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.widget.SimpleCursorTreeAdapter.<init>(SimpleCursorTreeAdapter.java:157)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.browse.max.Categories$MySimpleCursorTreeAdapter.<init>(Categories.java:62)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at com.browse.max.Categories.onCreate(Categories.java:44)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
09-11 14:33:10.565: ERROR/AndroidRuntime(161): ... 29 more
09-11 14:33:09.365:错误/AndroidRuntime(161):未捕获处理程序:由于未捕获异常,线程主线程正在退出
09-11 14:33:10.565:错误/AndroidRuntime(161):java.lang.RuntimeException:无法启动活动组件信息{com.home.max/com.browse.max.Categories}:java.lang.NullPointerException
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于android.app.ActivityThread.startActivityNow(ActivityThread.java:2242)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:631)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.widget.TabHost.setCurrentTab(TabHost.java:317)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:127)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:346)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.view.performClick(view.java:2344)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.view.onTouchEvent(view.java:4133)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.view.dispatchTouchEvent(view.java:3672)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:850)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:882)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1712)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1202)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.app.Activity.dispatchTouchEvent(Activity.java:1987)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1696)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.view.ViewRoot.handleMessage(ViewRoot.java:1658)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.os.Handler.dispatchMessage(Handler.java:99)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.os.Looper.loop(Looper.java:123)上
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于android.app.ActivityThread.main(ActivityThread.java:4203)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于java.lang.reflect.Method.invokenactive(本机方法)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于java.lang.reflect.Method.invoke(Method.java:521)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
09-11 14:33:10.565:错误/AndroidRuntime(161):在dalvik.system.NativeStart.main(本机方法)
09-11 14:33:10.565:错误/AndroidRuntime(161):由以下原因引起:java.lang.NullPointerException
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在com.browse.max.Categories$MySimpleCursorTreeAdapter.getChildrenCursor(Categories.java:69)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.widget.CursorTreeAdapter.getChildrenCursorHelper(CursorTreeAdapter.java:106)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于android.widget.SimpleCursorTreeAdapter.init(SimpleCursorTreeAdapter.java:172)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.widget.SimpleCursorTreeAdapter。(SimpleCursorTreeAdapter.java:157)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在com.browse.max.Categories$MySimpleCursorTreeAdapter。(Categories.java:62)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):位于com.browse.max.Categories.onCreate(Categories.java:44)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
09-11 14:33:10.565:ERROR/AndroidRuntime(161):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
09-11 14:33:10.565:错误/AndroidRuntime(161):。。。还有29个
如果异常确实在您指定的行中抛出,那么原因是R.id
为null
其他可能性是R
为null
或R.layout
为null。但如果其中任何一个是真的,那么NPE将由以下人员抛出:
setContentView(R.layout.cattest);
请张贴stacktrace并指出异常发生在哪一行。
NullPointers
非常容易跟踪。我不明白为什么会有这么多关于它们的问题……我已经添加了堆栈跟踪,并将特定行打印到了帖子的顶部。这是linecom.browse.max.Categories$MySimpleCur
setContentView(R.layout.cattest);