这是我的代码，在这里我试图从Arraylist中删除该项目并尝试使用notifyDataSetChanged更新布局项目。
public class GroupContactListingAdapter extends BaseAdapter {
private LayoutInflater mInflater;
private ArrayList<ContactListDto> groupListDto = new ArrayList<ContactListDto>();
private Activity context;
public static ArrayList<String> selectList;
@Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
/**
* Assigning the parameter
*
* @param mContext1
* Getting the context of the class
* @param contactList
* list to be display
* @param value
* if 0 all, if 1 unblocked and 2 blocked
* @param isContactList
* if 1 then contact list and if 0 search contact list
*/
public GroupContactListingAdapter(Activity mContext1,
ArrayList<ContactListDto> contactList) {
this.context = mContext1;
this.mInflater = (LayoutInflater) mContext1
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (this.groupListDto != null) {
this.groupListDto.clear();
}
this.groupListDto = contactList;
selectList = new ArrayList<String>();
}
@Override
public int getCount() {
return groupListDto.size();
}
@Override
public Object getItem(int position) {
return groupListDto.get(position);
}
@Override
public long getItemId(int arg0) {
return arg0;
}
@Override
public View getView(final int position, View convertView, ViewGroup arg2) {
final ViewHolder viewHolder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.group_listing_item, null);
viewHolder = new ViewHolder();
viewHolder.nameTextView = (TextView) convertView
.findViewById(R.id.group_name);
viewHolder.relative = (RelativeLayout) convertView
.findViewById(R.id.group_layout);
viewHolder.deleteContacts = (Button) convertView
.findViewById(R.id.btn_group_contact_delete);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.deleteContacts.setVisibility(View.VISIBLE);
viewHolder.deleteContacts
.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Helper.printLogD(" deleting position is " + position);
selectList.add(groupListDto.get(position)
.getContactId());
groupListDto.remove(groupListDto.get(position));
notifyDataSetChanged();
}
});
viewHolder.nameTextView.setText(groupListDto.get(position)
.getContactFullName());
if (position % 2 == 0) {
viewHolder.relative.setBackgroundColor(context.getResources()
.getColor(R.color.white));
} else {
viewHolder.relative.setBackgroundColor(context.getResources()
.getColor(R.color.list_even_color));
}
return convertView;
}
发生以下错误
12-18 11:43:01.895: E/ListView(24434): null
12-18 11:43:01.895: E/ListView(24434): java.lang.NullPointerException
12-18 11:43:01.895: E/ListView(24434): at com.hazemedia.stewdent.client.android.ui.adapter.GroupContactListingAdapter$ViewHolder.access$4(GroupContactListingAdapter.java:133)
12-18 11:43:01.895: E/ListView(24434): at com.hazemedia.stewdent.client.android.ui.adapter.GroupContactListingAdapter.getView(GroupContactListingAdapter.java:94)
12-18 11:43:01.895: E/ListView(24434): at android.widget.AbsListView.obtainView(AbsListView.java:1428)
12-18 11:43:01.895: E/ListView(24434): at android.widget.ListView.makeAndAddView(ListView.java:1801)
12-18 11:43:01.895: E/ListView(24434): at android.widget.ListView.fillSpecific(ListView.java:1339)
12-18 11:43:01.895: E/ListView(24434): at android.widget.ListView.layoutChildren(ListView.java:1625)
12-18 11:43:01.895: E/ListView(24434): at android.widget.AbsListView.onLayout(AbsListView.java:1279)
12-18 11:43:01.895: E/ListView(24434): at android.view.View.layout(View.java:7321)
12-18 11:43:01.895: E/ListView(24434): at android.widget.RelativeLayout.onLayout(RelativeLayout.java:912)
12-18 11:43:01.895: E/ListView(24434): at android.view.View.layout(View.java:7321)
12-18 11:43:01.895: E/ListView(24434): at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-18 11:43:01.895: E/ListView(24434): at android.view.View.layout(View.java:7321)
12-18 11:43:01.895: E/ListView(24434): at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-18 11:43:01.895: E/ListView(24434): at android.view.View.layout(View.java:7321)
12-18 11:43:01.895: E/ListView(24434): at android.view.ViewRoot.performTraversals(ViewRoot.java:1217)
12-18 11:43:01.895: E/ListView(24434): at android.view.ViewRoot.handleMessage(ViewRoot.java:1995)
12-18 11:43:01.895: E/ListView(24434): at android.os.Handler.dispatchMessage(Handler.java:99)
12-18 11:43:01.895: E/ListView(24434): at android.os.Looper.loop(Looper.java:150)
12-18 11:43:01.895: E/ListView(24434): at android.app.ActivityThread.main(ActivityThread.java:4389)
12-18 11:43:01.895: E/ListView(24434): at java.lang.reflect.Method.invokeNative(Native Method)
12-18 11:43:01.895: E/ListView(24434): at java.lang.reflect.Method.invoke(Method.java:507)
12-18 11:43:01.895: E/ListView(24434): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:849)
12-18 11:43:01.895: E/ListView(24434): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:607)
12-18 11:43:01.895: E/ListView(24434): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：3)
创建此问题是因为我没有在convertView实例中分析viewHolder。
convertView .setTag(viewHolder);
答案 1 :(得分：1)
尝试这种类型的代码可能会对您有所帮助，
@Override
public View getView(final int position, View convertView, ViewGroup arg2) {
ViewHolder mViewHolder;
if(convertView == null){
mViewHolder = new ViewHolder();
mInflater = (LayoutInflater) context .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = mInflater.inflate(R.layout.group_listing_item, null);
mViewHolder. nameTextView = (TextView) convertView .findViewById(R.id.group_name);
mViewHolder.relative = (RelativeLayout) convertView .findViewById(R.id.group_layout);
mViewHolder.deleteContacts = (Button) convertView .findViewById(R.id.btn_group_contact_delete);
convertView.setTag(mViewHolder);
} else {
mViewHolder = (ViewHolder)convertView.getTag();
}
deleteContacts.setVisibility(View.VISIBLE);
deleteContacts .setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Helper.printLogD(" deleting position is " + position);
selectList.add(groupListDto.get(position) .getContactId());
groupListDto.remove(groupListDto.get(position));
notifyDataSetChanged();
}
});
nameTextView.setText(groupListDto.get(position) .getContactFullName());
if (position % 2 == 0) {
relative.setBackgroundColor(context.getResources() .getColor(R.color.white));
} else {
relative.setBackgroundColor(context.getResources() .getColor(R.color.list_even_color));
}
return convertView;
}
public class ViewHolder{
TextView nameTextView;
RelativeLayout relative;
Button deleteContacts;
}