我正在自定义Android listView。以下是我的custtom适配器的代码
public class MyAdapter extends BaseAdapter {
Context context;
ArrayList<menu_itemss>list;
String[] textArray;
int[] images;
menu_itemss m;
public class menu_itemss
{
public String text;
public int image;
public menu_itemss(String text,int images)
{
this.text=text;
this.image=images;
}
}
public class ViewHolders
{
ImageView imageView;
TextView textView;
public ViewHolders(View view)
{
textView=(TextView)view.findViewById(R.id.textView4);
imageView=(ImageView)view.findViewById(R.id.imageView);
}
}
public MyAdapter(Context contexts,String[] arr)
{
list=new ArrayList<menu_itemss>();
textArray=arr;
this.context=contexts;
images= new int[]{R.drawable.logo, R.drawable.logo, R.drawable.logo,
R.drawable.logo};
for (int i=0;i<textArray.length;i++)
{
m=new menu_itemss(textArray[i],images[i]);
list.add(m);
}
}
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row=convertView;
ViewHolders holder = null;
if (row==null)
{
LayoutInflater inflater=(LayoutInflater)
context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.list,parent,false);
holder=new ViewHolders(row);
row.setTag(holder);
}
else
{
holder=(ViewHolders)row.getTag();
}
menu_itemss item=list.get(position);
holder.imageView.setImageResource(item.image);
holder.textView.setText(item.text);
return row;
}
}
以下是使用Adapter
的ListView对象声明 ListView listView=(ListView)findViewById(R.id.list);
ListAdapter adapter=new MyAdapter(getApplicationContext(),s);
listView.setAdapter(adapter);
当我构建代码时，Android工作室不会显示任何错误，但是当我在我的Android设备上运行时，会显示以下错误
Unfortunately ! your application stopped working!
LOG Cat：
FATAL EXCEPTION: main
Process: com.example.mashood.muftiattaullahmultanicom, PID: 27743
java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
at com.example.mashood.muftiattaullahmultanicom.MyAdapter$ViewHolders.<init>(MyAdapter.java:48)
at com.example.mashood.muftiattaullahmultanicom.MyAdapter.getView(MyAdapter.java:95)
at android.widget.AbsListView.obtainView(AbsListView.java:2402)
at android.widget.ListView.makeAndAddView(ListView.java:1891)
at android.widget.ListView.fillDown(ListView.java:713)
at android.widget.ListView.fillFromTop(ListView.java:779)
at android.widget.ListView.layoutChildren(ListView.java:1699)
at android.widget.AbsListView.onLayout(AbsListView.java:2206)
at android.view.View.layout(View.java:16075)
at android.view.ViewGroup.layout(ViewGroup.java:5300)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1077)
at android.view.View.layout(View.java:16075)
at android.view.ViewGroup.layout(ViewGroup.java:5300)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:16075)
at android.view.ViewGroup.layout(ViewGroup.java:5300)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:16075)
at android.view.ViewGroup.layout(ViewGroup.java:5300)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:16075)
at android.view.ViewGroup.layout(ViewGroup.java:5300)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:16075)
at android.view.ViewGroup.layout(ViewGroup.java:5300)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:16075)
at android.view.ViewGroup.layout(ViewGroup.java:5300)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2119)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1873)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1073)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5988)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5910)
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:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
在这方面的任何帮助将不胜感激。谢谢你
答案 0 :(得分：0)
请将充气视图分配给该行。
row = inflater.inflate(R.layout.list,parent,false);
崩溃是因为您将null对象传递给ViewHolders。