Android 在我的片段中添加微调器时总是出现NullPointerException
我正在尝试创建一个带有微调器的联系人列表,您可以在其中为联系人选择不同的角色 在将微调器添加到联系人列表(list_item.xml)的布局时,我总是会遇到NullPointerException,我就是找不到我的错误 kontakte_片段-XML文件Android 在我的片段中添加微调器时总是出现NullPointerException,android,xml,android-layout,android-fragments,android-spinner,Android,Xml,Android Layout,Android Fragments,Android Spinner,我正在尝试创建一个带有微调器的联系人列表,您可以在其中为联系人选择不同的角色 在将微调器添加到联系人列表(list_item.xml)的布局时,我总是会遇到NullPointerException,我就是找不到我的错误 kontakte_片段-XML文件 <?xml version="1.0" encoding="utf-8"?> <ScrollView android:layout_width="wrap_content" androi
<?xml version="1.0" encoding="utf-8"?>
<ScrollView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context="match_parent"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="1"
android:background="#ffffff">
<ListView
android:layout_width="fill_parent"
android:layout_height="657dp"
android:id="@+id/listViewKontakte" />
</LinearLayout>
</ScrollView>
我的列表的布局(List_item.xml)
KontakteFragment-活动类
public class KontakteFragment extends Fragment {
private ArrayList<String> data = new ArrayList<String>();
Spinner spinner;
ArrayAdapter<CharSequence> adapter;
public static KontakteFragment newInstance() {
KontakteFragment fragment = new KontakteFragment();
return fragment;
}
public KontakteFragment(){
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.kontakte_fragment, container, false);
ListView lv = (ListView) rootView.findViewById(R.id.listViewKontakte);
generateListContent();
lv.setAdapter(new MyListAdapter(getContext(), R.layout.list_item, data));
spinner = (Spinner) rootView.findViewById(R.id.spinnerKontakte);
adapter = ArrayAdapter.createFromResource(getActivity().getBaseContext(), R.array.profile_kontakte, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
return rootView;
}
private void generateListContent() {
for(int i = 0; i < 55; i++){
data.add("This is row number" + i);
}
}
private class MyListAdapter extends ArrayAdapter<String>{
private int layout;
public MyListAdapter(Context context, int resource, List<String> objects) {
super(context, resource, objects);
layout = resource;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder mainViewHolder = null;
if(convertView == null){
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(layout, parent, false);
ViewHolder viewHolder = new ViewHolder();
viewHolder.thumbnail = (ImageView) convertView.findViewById(R.id.kontaktListePic);
viewHolder.titel = (TextView) convertView.findViewById(R.id.textview1kontakteTitel);
viewHolder.unterTitel = (TextView) convertView.findViewById(R.id.untertitelKontaktListe);
convertView.setTag(viewHolder);
}
else{
mainViewHolder = (ViewHolder) convertView.getTag();
mainViewHolder.titel.setText(getItem(position));
mainViewHolder.unterTitel.setText(getItem(position));
}
return convertView;
}
}
public class ViewHolder {
ImageView thumbnail;
TextView titel;
TextView unterTitel;
}
} // This is the end of our KontakteFragment Class
公共类KontakteFragment扩展片段{
private ArrayList data=new ArrayList();
纺纱机;
阵列适配器;
公共静态KontakteFragment newInstance(){
KontakteFragment片段=新的KontakteFragment();
返回片段;
}
公共广播电台{
}
CreateView上的公共视图(布局、充气机、视图组容器、捆绑包保存状态){
视图根视图=充气机。充气(R.layout.kontakte_碎片,容器,假);
ListView lv=(ListView)rootView.findViewById(R.id.listViewKontakte);
generateListContent();
lv.setAdapter(新的MyListAdapter(getContext(),R.layout.list_项,数据));
微调器=(微调器)rootView.findviewbyd(R.id.spinnerKontakte);
adapter=ArrayAdapter.createFromResource(getActivity().getBaseContext(),R.array.profile\u kontakte,android.R.layout.simple\u spinner\u item);
setDropDownViewResource(android.R.layout.simple\u微调器\u下拉菜单\u项);
旋转器。设置适配器(适配器);
返回rootView;
}
私有void generateListContent(){
对于(int i=0;i<55;i++){
data.add(“这是行号”+i);
}
}
私有类MyListAdapter扩展了ArrayAdapter{
专用int布局;
公共MyListAdapter(上下文、int资源、列表对象){
超级(上下文、资源、对象);
布局=资源;
}
@凌驾
公共视图getView(int位置、视图转换视图、视图组父视图){
ViewHolder mainViewHolder=null;
if(convertView==null){
LayoutInflater充气器=LayoutInflater.from(getContext());
convertView=充气机。充气(布局,父级,假);
ViewHolder ViewHolder=新ViewHolder();
viewHolder.thumboil=(ImageView)convertView.findViewById(R.id.kontaktListPic);
viewHolder.titel=(TextView)convertView.findViewById(R.id.textView1kontaktitel);
viewHolder.unterTitel=(TextView)convertView.findViewById(R.id.untertitelKontaktListe);
convertView.setTag(viewHolder);
}
否则{
mainViewHolder=(ViewHolder)convertView.getTag();
mainViewHolder.titel.setText(getItem(position));
mainViewHolder.untertel.setText(getItem(position));
}
返回视图;
}
}
公共类视图持有者{
图像视图缩略图;
文本视图滴度;
TextView Untertel;
}
}//这是我们的KontakteFragment课程的结束
您正在片段的布局中查找微调器,但它在LitsView的元素布局中。
您可以在适配器的getView
方法中获得对微调器的正确引用,如下所示:
Spinner yourSpinner = (Spinner) convertView.findViewById(R.id.spinnerKontakte);
您在片段中的何处添加了微调器?你这样做是错误的
public class KontakteFragment extends Fragment {
private ArrayList<String> data = new ArrayList<String>();
ArrayAdapter<CharSequence> adapter;
public static KontakteFragment newInstance() {
KontakteFragment fragment = new KontakteFragment();
return fragment;
}
public KontakteFragment(){
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.kontakte_fragment, container, false);
ListView lv = (ListView) rootView.findViewById(R.id.listViewKontakte);
generateListContent();
lv.setAdapter(new MyListAdapter(getContext(), R.layout.list_item, data));
adapter = ArrayAdapter.createFromResource(getActivity().getBaseContext(), R.array.profile_kontakte, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
return rootView;
}
private void generateListContent() {
for(int i = 0; i < 55; i++){
data.add("This is row number" + i);
}
}
private class MyListAdapter extends ArrayAdapter<String>{
private int layout;
public MyListAdapter(Context context, int resource, List<String> objects) {
super(context, resource, objects);
layout = resource;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder mainViewHolder = null;
if(convertView == null){
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(layout, parent, false);
ViewHolder viewHolder = new ViewHolder();
viewHolder.thumbnail = (ImageView) convertView.findViewById(R.id.kontaktListePic);
viewHolder.titel = (TextView) convertView.findViewById(R.id.textview1kontakteTitel);
viewHolder.unterTitel = (TextView) convertView.findViewById(R.id.untertitelKontaktListe);
convertView.setTag(viewHolder);
viewHolder.spinner = (Spinner)convertView.findViewById(R.id.spinnerKontakte);
}
else{
mainViewHolder = (ViewHolder) convertView.getTag();
mainViewHolder.titel.setText(getItem(position));
mainViewHolder.unterTitel.setText(getItem(position));
// here you have to set data to spinner
}
return convertView;
}
}
public class ViewHolder {
ImageView thumbnail;
TextView titel;
TextView unterTitel;
Spinner spinner
}
}
公共类KontakteFragment扩展片段{
private ArrayList data=new ArrayList();
阵列适配器;
公共静态KontakteFragment newInstance(){
KontakteFragment片段=新的KontakteFragment();
返回片段;
}
公共广播电台{
}
CreateView上的公共视图(布局、充气机、视图组容器、捆绑包保存状态){
视图根视图=充气机。充气(R.layout.kontakte_碎片,容器,假);
ListView lv=(ListView)rootView.findViewById(R.id.listViewKontakte);
generateListContent();
lv.setAdapter(新的MyListAdapter(getContext(),R.layout.list_项,数据));
adapter=ArrayAdapter.createFromResource(getActivity().getBaseContext(),R.array.profile\u kontakte,android.R.layout.simple\u spinner\u item);
setDropDownViewResource(android.R.layout.simple\u微调器\u下拉菜单\u项);
旋转器。设置适配器(适配器);
返回rootView;
}
私有void generateListContent(){
对于(int i=0;i<55;i++){
data.add(“这是行号”+i);
}
}
私有类MyListAdapter扩展了ArrayAdapter{
专用int布局;
公共MyListAdapter(上下文、int资源、列表对象){
超级(上下文、资源、对象);
布局=资源;
}
@凌驾
公共视图getView(int位置、视图转换视图、视图组父视图){
ViewHolder mainViewHolder=null;
if(convertView==null){
LayoutInflater充气器=LayoutInflater.from(getContext());
convertView=充气机。充气(布局,父级,假);
ViewHolder ViewHolder=新ViewHolder();
viewHolder.thumboil=(ImageView)convertView.findViewById(R.id.kontaktListPic);
viewHolder.titel=(TextView)convertView.findViewById(R.id.textView1kontaktitel);
viewHolder.unterTitel=(TextView)convertView.findViewById(R.id.untertitelKontaktListe);
convertView.setTag(viewHolder);
viewHolder.spinner=(微调器)convertView.findViewById(R.id.spinnerKontakte);
}
否则{
mainViewHolder=(ViewHolder)convertView.getTag();
mainViewHolder.titel.setText(getItem(position));
mainViewHolder.untertel.setText(getItem(position));
//在这里,您必须将数据设置为微调器
}
返回视图;
}
}
公共类视图持有者{
图像视图缩略图;
文本视图滴度;
Te
public class KontakteFragment extends Fragment {
private ArrayList<String> data = new ArrayList<String>();
ArrayAdapter<CharSequence> adapter;
public static KontakteFragment newInstance() {
KontakteFragment fragment = new KontakteFragment();
return fragment;
}
public KontakteFragment(){
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.kontakte_fragment, container, false);
ListView lv = (ListView) rootView.findViewById(R.id.listViewKontakte);
generateListContent();
lv.setAdapter(new MyListAdapter(getContext(), R.layout.list_item, data));
adapter = ArrayAdapter.createFromResource(getActivity().getBaseContext(), R.array.profile_kontakte, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
return rootView;
}
private void generateListContent() {
for(int i = 0; i < 55; i++){
data.add("This is row number" + i);
}
}
private class MyListAdapter extends ArrayAdapter<String>{
private int layout;
public MyListAdapter(Context context, int resource, List<String> objects) {
super(context, resource, objects);
layout = resource;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder mainViewHolder = null;
if(convertView == null){
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(layout, parent, false);
ViewHolder viewHolder = new ViewHolder();
viewHolder.thumbnail = (ImageView) convertView.findViewById(R.id.kontaktListePic);
viewHolder.titel = (TextView) convertView.findViewById(R.id.textview1kontakteTitel);
viewHolder.unterTitel = (TextView) convertView.findViewById(R.id.untertitelKontaktListe);
convertView.setTag(viewHolder);
viewHolder.spinner = (Spinner)convertView.findViewById(R.id.spinnerKontakte);
}
else{
mainViewHolder = (ViewHolder) convertView.getTag();
mainViewHolder.titel.setText(getItem(position));
mainViewHolder.unterTitel.setText(getItem(position));
// here you have to set data to spinner
}
return convertView;
}
}
public class ViewHolder {
ImageView thumbnail;
TextView titel;
TextView unterTitel;
Spinner spinner
}
}