没有什么是null但我仍然得到一个空指针异常

时间：2014-05-20 21:37:20

标签： java android android-fragments android-listview android-arrayadapter

在我的片段中，convertView为null，因此我将其设置为新视图。然后我打印出要发送到super.getView（）的所有内容，看看它是否为null。但我仍然在

上得到一个nullpointerexception 
view = super.getView(position, convertView, parent);

代码：

    listView.setAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, R.id.textView1, list.items)
            {
                @Override
                public View getView(final int position, View convertView, ViewGroup parent)
                {
                    View view;
                    if (convertView == null)
                    {
                        System.err.println("convertView was null... updating");
                        LayoutInflater infl = getActivity().getLayoutInflater();
                        convertView = infl.inflate(android.R.layout.simple_list_item_1, parent, false);
                    }
                    System.out.println(position + "\n" + convertView + "\n" + parent);
                    view = super.getView(position, convertView, parent);
                    String entry = list.items.get(position);
                    TextView text1 = (TextView) view.findViewById(R.id.textView1);
                    text1.setText(entry);
                    return view;
                }
            });
    return view;

position，convertView和parent的值：

05-20 16:32:57.760: I/System.out(18373): 0
05-20 16:32:57.760: I/System.out(18373): android.widget.TextView{42caa628 V.ED....     ......I. 0,0-0,0 #1020014 android:id/text1}
05-20 16:32:57.760: I/System.out(18373): android.widget.ListView{42c32a68 VFED.VC. ......ID 0,88-1080,1442 #7f080004 app:id/list}

有什么我可以改变来修复/改善这个吗？提前谢谢。

将根据请求提供其他代码和信息。

完整logcat：

05-20 16:45:26.360: D/dalvikvm(22735): Late-enabling CheckJNI
05-20 16:45:26.580: D/dalvikvm(22735): JIT code cache reset in 0 ms (0 bytes 7/0)
05-20 16:45:26.580: D/dalvikvm(22735): GC_FOR_ALLOC freed 451K, 3% free 22716K/23216K, paused 27ms, total 27ms
05-20 16:45:26.650: D/dalvikvm(22735): JIT code cache reset in 0 ms (0 bytes 8/0)
05-20 16:45:26.650: D/dalvikvm(22735): GC_FOR_ALLOC freed 496K, 3% free 22727K/23276K, paused 24ms, total 24ms
05-20 16:45:26.710: D/dalvikvm(22735): GC_FOR_ALLOC freed 512K, 3% free 22728K/23288K, paused 20ms, total 20ms
05-20 16:45:26.760: D/dalvikvm(22735): GC_FOR_ALLOC freed 501K, 3% free 22737K/23288K, paused 19ms, total 19ms
05-20 16:45:26.760: I/System.out(22735): FamilyLists
05-20 16:45:26.790: D/dalvikvm(22735): GC_FOR_ALLOC freed 71K, 3% free 22769K/23288K, paused 21ms, total 21ms
05-20 16:45:26.820: D/dalvikvm(22735): GC_FOR_ALLOC freed <1K, 3% free 22790K/23288K, paused 24ms, total 24ms
05-20 16:45:26.820: I/dalvikvm-heap(22735): Grow heap (frag case) to 22.380MB for 82960-byte allocation
05-20 16:45:26.840: D/dalvikvm(22735): GC_FOR_ALLOC freed <1K, 3% free 22871K/23372K, paused 21ms, total 21ms
05-20 16:45:26.870: D/dalvikvm(22735): GC_FOR_ALLOC freed 43K, 3% free 22895K/23372K, paused 18ms, total 18ms
05-20 16:45:26.910: D/dalvikvm(22735): GC_FOR_ALLOC freed 107K, 3% free 22936K/23456K, paused 20ms, total 20ms
05-20 16:45:26.950: I/Adreno-EGL(22735): <qeglDrvAPI_eglInitialize:320>: EGL 1.4 QUALCOMM Build: I0404c4692afb8623f95c43aeb6d5e13ed4b30ddbDate: 11/06/13
05-20 16:45:26.970: D/OpenGLRenderer(22735): Enabling debug mode 0
05-20 16:45:26.980: W/System.err(22735): convertView was null... updating
05-20 16:45:26.980: I/System.out(22735): 0
05-20 16:45:26.980: I/System.out(22735): android.widget.TextView{42c9e3b8 V.ED.... ......I. 0,0-0,0 #1020014 android:id/text1}
05-20 16:45:26.980: I/System.out(22735): android.widget.ListView{42c4bbc8 VFED.VC. ......ID 0,88-1080,1442 #7f080004 app:id/list}
05-20 16:45:26.980: D/AndroidRuntime(22735): Shutting down VM
05-20 16:45:26.980: W/dalvikvm(22735): threadid=1: thread exiting with uncaught exception (group=0x41613ba8)
05-20 16:45:26.980: E/AndroidRuntime(22735): FATAL EXCEPTION: main
05-20 16:45:26.980: E/AndroidRuntime(22735): Process: com.mail929.android.familylists, PID: 22735
05-20 16:45:26.980: E/AndroidRuntime(22735): java.lang.NullPointerException
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:392)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at com.mail929.android.familylists.ListFragment$2.getView(ListFragment.java:59)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.AbsListView.obtainView(AbsListView.java:2263)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.ListView.makeAndAddView(ListView.java:1790)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.ListView.fillDown(ListView.java:691)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.ListView.fillFromTop(ListView.java:752)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.ListView.layoutChildren(ListView.java:1630)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.AbsListView.onLayout(AbsListView.java:2091)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.View.layout(View.java:14817)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1055)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.View.layout(View.java:14817)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.View.layout(View.java:14817)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:743)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.View.layout(View.java:14817)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.View.layout(View.java:14817)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.View.layout(View.java:14817)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.View.layout(View.java:14817)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewGroup.layout(ViewGroup.java:4631)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1987)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1744)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.Choreographer.doCallbacks(Choreographer.java:574)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.Choreographer.doFrame(Choreographer.java:544)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.os.Handler.handleCallback(Handler.java:733)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.os.Handler.dispatchMessage(Handler.java:95)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.os.Looper.loop(Looper.java:136)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at android.app.ActivityThread.main(ActivityThread.java:5017)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at java.lang.reflect.Method.invokeNative(Native Method)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at java.lang.reflect.Method.invoke(Method.java:515)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
05-20 16:45:26.980: E/AndroidRuntime(22735):    at dalvik.system.NativeStart.main(Native Method)

1 个答案:

答案 0 :(得分：3)

您正在使用android.R.layout.simple_list_item_1，其TextView的ID为android.R.id.text1，不是 R.id.textView1 source。

请尝试以下代码，并了解Adapter的工作原理。互联网上提供ListView和自定义Adapter上的大量内容：

listView.setAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, android.R.id.text1, list.items)
            {
                @Override
                public View getView(final int position, View convertView, ViewGroup parent)
                {
                    View view = super.getView(position, convertView, parent);
                    String entry = list.items.get(position);
                    TextView text1 = (TextView) view.findViewById(android.R.id.text1);
                    text1.setText(entry);
                    return view;
                }
            });
相关问题
最新问题