NullPointerException异常的自定义适配器getView [英] NullPointerException in custom adapter getView
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问题描述
我在编码一个ListView,有一个自定义列表给它一个自定义的适配器。
I'm coding a custom adapter for a ListView that has a custom list to it.
很明显,我必须写在 getView
功能。所以这里是我的code:
obviously, I have to write the getView
function. so here is my code:
/*1*/ public View getView(int position, View convertView, ViewGroup parent) {
/*2*/ View vi = convertView;
/*3*/ if (convertView == null)
/*4*/ vi = inflater.inflate(R.layout.result_list_item, null);
/*5*/
/*6*/ TextView title = (TextView) vi.findViewById(R.id.tvTitle);
/*7*/ TextView subtitle = (TextView) vi.findViewById(R.id.tvSubTitle);
/*8*/ ImageView image = (ImageView) vi.findViewById(R.id.imageView1);
/*9*/
/*10*/ title.setText(data.get(position).getDescription().toString());
/*11*/ subtitle.setText(data.get(position).getDate().toString());
/*12*/ String img = "http://someLink/" + data.get(position).getId() + "a_t.jpg";
/*13*/ imageLoader.DisplayImage(img, image);
/*14*/ return vi;
/*15*/ }
不过,我注意到,在线路6号方案与空指针异常崩溃。
But, I have noticed that on line number 6 the program crashes with a NullPointer exception.
这是我的崩溃报告:
04-18 09:33:32.745: E/AndroidRuntime(2209): FATAL EXCEPTION: main
04-18 09:33:32.745: E/AndroidRuntime(2209): java.lang.NullPointerException
04-18 09:33:32.745: E/AndroidRuntime(2209): at com.package.mojo.NoPicAdapter.getView(NoPicAdapter.java:46)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.AbsListView.obtainView(AbsListView.java:1554)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.ListView.measureHeightOfChildren(ListView.java:1264)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.ListView.onMeasure(ListView.java:1175)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.View.measure(View.java:8366)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.LinearLayout.measureVertical(LinearLayout.java:386)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.View.measure(View.java:8366)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.View.measure(View.java:8366)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.View.measure(View.java:8366)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.View.measure(View.java:8366)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.ViewRoot.performTraversals(ViewRoot.java:847)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.view.ViewRoot.handleMessage(ViewRoot.java:1868)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.os.Handler.dispatchMessage(Handler.java:99)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.os.Looper.loop(Looper.java:123)
04-18 09:33:32.745: E/AndroidRuntime(2209): at android.app.ActivityThread.main(ActivityThread.java:3691)
04-18 09:33:32.745: E/AndroidRuntime(2209): at java.lang.reflect.Method.invokeNative(Native Method)
04-18 09:33:32.745: E/AndroidRuntime(2209): at java.lang.reflect.Method.invoke(Method.java:507)
04-18 09:33:32.745: E/AndroidRuntime(2209): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847)
04-18 09:33:32.745: E/AndroidRuntime(2209): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605)
04-18 09:33:32.745: E/AndroidRuntime(2209): at dalvik.system.NativeStart.main(Native Method)
当然,布局和自身存在的项目...
of course, the layout and the items themselves exist...
什么想法?
更新:当我看到的变量在调试时,我看到六
未充气(六== NULL
),为什么?
update: when i look at the variables while debugging, I see that vi
was not inflated (vi == null
), why?
推荐答案
更改此:
vi = inflater.inflate(R.layout.result_list_item, null);
要这样:
vi = inflater.inflate(R.layout.result_list_item, parent, false);
这是您的适配器应该的:
this is how your adapter should be:
public class NoPicAdapter extends ArrayAdapter<NewAndCalendar> {
private ArrayList<NewAndCalendar> data;
private Activity mActivity;
private LayoutInflater inflater = null;
public NoPicAdapter(Activity a, ArrayList<NewAndCalendar> d) {
super(a, R.layout.no_pic_list_item, d);
mActivity = a;
data = d;
inflater = (LayoutInflater) mActivity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View vi = convertView;
if (vi == null)
vi = inflater.inflate(R.layout.no_pic_list_item, parent, false);
TextView title = (TextView) vi.findViewById(R.id.noPicTitle);
TextView subtitle = (TextView) vi.findViewById(R.id.noPicSubtitle);
title.setText(data.get(position).getmTitle());
subtitle.setText(data.get(position).getmPubDate());
return vi;
}
}
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