android：at android.widget.RelativeLayout.onMeasure(Relayout)

04-03 06:00:07.896: E/AndroidRuntime(7328): FATAL EXCEPTION: main
04-03 06:00:07.896: E/AndroidRuntime(7328): java.lang.NullPointerException
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:529)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.View.measure(View.java:15518)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at com.example.radiobuttonlisttest.qer.setListViewHeightBasedOnChildren(qer.java:81)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at com.example.radiobuttonlisttest.qer.getView(qer.java:64)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.AbsListView.obtainView(AbsListView.java:2159)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.ListView.makeAndAddView(ListView.java:1831)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.ListView.fillDown(ListView.java:674)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.ListView.fillFromTop(ListView.java:735)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.ListView.layoutChildren(ListView.java:1652)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.AbsListView.onLayout(AbsListView.java:1994)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.View.layout(View.java:14008)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewGroup.layout(ViewGroup.java:4373)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1663)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1521)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.View.layout(View.java:14008)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewGroup.layout(ViewGroup.java:4373)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.View.layout(View.java:14008)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewGroup.layout(ViewGroup.java:4373)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1663)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1521)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.View.layout(View.java:14008)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewGroup.layout(ViewGroup.java:4373)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.View.layout(View.java:14008)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewGroup.layout(ViewGroup.java:4373)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1892)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1711)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.Choreographer.doCallbacks(Choreographer.java:562)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.Choreographer.doFrame(Choreographer.java:532)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.os.Handler.handleCallback(Handler.java:725)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.os.Handler.dispatchMessage(Handler.java:92)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.os.Looper.loop(Looper.java:137)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at android.app.ActivityThread.main(ActivityThread.java:5041)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at java.lang.reflect.Method.invokeNative(Native Method)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at java.lang.reflect.Method.invoke(Method.java:511)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-03 06:00:07.896: E/AndroidRuntime(7328):  at dalvik.system.NativeStart.main(Native Method)
04-03 06:01:57.828: E/Trace(7399): error opening trace file: No such file or directory (2)

不知道什么原因，当我的adapter是在getview时，通过inflater.inflate(相对布局)则会直接崩溃。只要套一层线性布局就不会崩溃了。这是为什么呢？