Android:不确定为什么我的列表视图变得混乱不堪? [英] Android: Not sure why my listview is getting all jumbled up?
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问题描述
我实现了一个可以正常工作的ListView，直到我添加了5个以上的项目和2个标题.我不能完全确定为什么某些项目没有出现而其他项目却多次出现.修复此问题的任何帮助将不胜感激.代码包括在下面.
Toolbox.java
public class Toolbox extends Fragment {
private ListView lstView;
private View rootView;
List<Tools> tools;
public static Toolbox newInstance(Context context) {
Toolbox fragment = new Toolbox();
return fragment;
}
public Toolbox() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
((MainActivity) getActivity()).setActionBarTitle("Technical Toolbox");
rootView = inflater.inflate(R.layout.fragment_toolbox, container, false);
lstView =(ListView) rootView.findViewById(R.id.list);
final FragmentActivity c = getActivity();
//final RecyclerView recyclerView = (RecyclerView) recView.findViewById(R.id.reView);
setToolBoxData();
setToolBoxAdapter();
return rootView;
}
private void setToolBoxAdapter() {
ListArrayAdapter adapter = new ListArrayAdapter(getActivity(),tools);
lstView.setAdapter(adapter);
}
private void setToolBoxData(){
tools=new ArrayList<>();
tools.add(new Header("Languages"));
tools.add(new ListItem("Android",R.drawable.ic_android));
tools.add(new ListItem("XML", R.drawable.ic_xml));
tools.add(new ListItem("Java",R.drawable.ic_java));
tools.add(new ListItem("JavaScript", R.drawable.ic_javascript));
tools.add(new ListItem("C++", R.drawable.ic_cpp));
tools.add(new ListItem("Visual Basic", R.drawable.ic_vb));
tools.add(new ListItem("HTML", R.drawable.ic_html));
tools.add(new ListItem("CSS", R.drawable.ic_css));
tools.add(new Header("Source Control"));
tools.add(new ListItem("Git", R.drawable.ic_git));
tools.add(new ListItem("GitHub", R.drawable.ic_github_cat));
tools.add(new ListItem("SourceTree", R.drawable.ic_sourcetree));
tools.add(new ListItem("BitBucket", R.drawable.ic_bitbucket));
tools.add(new Header("DataBase"));
tools.add(new ListItem("Parse", R.drawable.ic_parse));
tools.add(new ListItem("MS Access", R.drawable.ic_access));
tools.add(new ListItem("SQL", R.drawable.ic_sql));
tools.add(new Header("Design & IDE Tools"));
tools.add(new ListItem("Android Studio", R.drawable.ic_androidstudio));
tools.add(new ListItem("Visual Studio", R.drawable.ic_visual_studio));
tools.add(new ListItem("Genymotion", R.drawable.ic_genymotion));
tools.add(new ListItem("Ionic", R.drawable.ic_ionic));
tools.add(new Header("Office Tools"));
tools.add(new ListItem("MS Project", R.drawable.ic_project));
tools.add(new ListItem("MS Visio", R.drawable.ic_visio));
tools.add(new ListItem("MS Excel", R.drawable.ic_excel));
tools.add(new ListItem("MS Word", R.drawable.ic_word));
}
}
ListArrayAdapter.java
public class ListArrayAdapter extends ArrayAdapter<Tools> {
private LayoutInflater mInflater;
public enum RowType{ LIST_ITEM, HEADER_ITEM }
public ListArrayAdapter(Context context, List<Tools> tools){
super(context, 0, tools);
mInflater = LayoutInflater.from(context);
}
@Override
public int getViewTypeCount(){return RowType.values().length;}
@Override
public int getItemViewType(int pos){return getItem(pos).getViewType();}
private static final int TYPE_ITEM = 0;
private static final int TYPE_SEPARATOR = 1;
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
int rowType = getItemViewType(position);
View View;
if (convertView == null) {
holder = new ViewHolder();
switch (rowType) {
case TYPE_ITEM:
convertView = mInflater.inflate(R.layout.listview_item, null);
holder.View=getItem(position).getView(mInflater, convertView);
break;
case TYPE_SEPARATOR:
convertView = mInflater.inflate(R.layout.list_title, null);
holder.View=getItem(position).getView(mInflater, convertView);
break;
}
convertView.setTag(holder);
}
else
{
holder = (ViewHolder) convertView.getTag();
}
return convertView;
}
public static class ViewHolder {
public View View;
}
}
Tools.java
public interface Tools {
public int getViewType();
public View getView(LayoutInflater inflater, View convertView);
}
ListItem.java
public class ListItem implements Tools {
private final String str1;
private final int pic1;
public ListItem(String text1, int pic1) {
this.str1 = text1;
this.pic1 = pic1;
}
@Override
public int getViewType() {
return ListArrayAdapter.RowType.LIST_ITEM.ordinal();
}
@Override
public View getView(LayoutInflater inflater, View convertView) {
View view;
if (convertView == null) {
view = (View) inflater.inflate(R.layout.listview_item, null);
// Do some initialization
} else {
view = convertView;
}
TextView text1 = (TextView) view.findViewById(R.id.listText);
ImageView picture1 = (ImageView) view.findViewById(R.id.listIcon);
text1.setText(str1);
picture1.setImageResource(pic1);
return view;
}
}
Header.java
public class Header implements Tools {
private final String name;
public Header(String name) {
this.name = name;
}
@Override
public int getViewType() {
return ListArrayAdapter.RowType.HEADER_ITEM.ordinal();
}
@Override
public View getView(LayoutInflater inflater, View convertView) {
View view;
if (convertView == null) {
view = (View) inflater.inflate(R.layout.header, null);
// Do some initialization
} else {
view = convertView;
}
TextView text = (TextView) view.findViewById(R.id.separator);
text.setText(name);
return view;
}
}
解决方案
您仅在if (convertView == null)情况下填充行小部件.如果convertView不是null，则只需将其返回原样即可，这意味着它将具有来自某些先前position的数据，而不是所请求的position的数据.
IOW，您需要在每次 getView()调用时调用诸如setText()和setImageResource()之类的方法，以使用请求的position的数据填充行的小部件.
I implemented a ListView that worked correctly until I added more than 5 items and 2 headers. Im not entirely sure why some items are not appearing and others are appearing multiple times. Any assistance in fixing this will be much appreciated. Code is include below.
Toolbox.java
public class Toolbox extends Fragment {
private ListView lstView;
private View rootView;
List<Tools> tools;
public static Toolbox newInstance(Context context) {
Toolbox fragment = new Toolbox();
return fragment;
}
public Toolbox() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
((MainActivity) getActivity()).setActionBarTitle("Technical Toolbox");
rootView = inflater.inflate(R.layout.fragment_toolbox, container, false);
lstView =(ListView) rootView.findViewById(R.id.list);
final FragmentActivity c = getActivity();
//final RecyclerView recyclerView = (RecyclerView) recView.findViewById(R.id.reView);
setToolBoxData();
setToolBoxAdapter();
return rootView;
}
private void setToolBoxAdapter() {
ListArrayAdapter adapter = new ListArrayAdapter(getActivity(),tools);
lstView.setAdapter(adapter);
}
private void setToolBoxData(){
tools=new ArrayList<>();
tools.add(new Header("Languages"));
tools.add(new ListItem("Android",R.drawable.ic_android));
tools.add(new ListItem("XML", R.drawable.ic_xml));
tools.add(new ListItem("Java",R.drawable.ic_java));
tools.add(new ListItem("JavaScript", R.drawable.ic_javascript));
tools.add(new ListItem("C++", R.drawable.ic_cpp));
tools.add(new ListItem("Visual Basic", R.drawable.ic_vb));
tools.add(new ListItem("HTML", R.drawable.ic_html));
tools.add(new ListItem("CSS", R.drawable.ic_css));
tools.add(new Header("Source Control"));
tools.add(new ListItem("Git", R.drawable.ic_git));
tools.add(new ListItem("GitHub", R.drawable.ic_github_cat));
tools.add(new ListItem("SourceTree", R.drawable.ic_sourcetree));
tools.add(new ListItem("BitBucket", R.drawable.ic_bitbucket));
tools.add(new Header("DataBase"));
tools.add(new ListItem("Parse", R.drawable.ic_parse));
tools.add(new ListItem("MS Access", R.drawable.ic_access));
tools.add(new ListItem("SQL", R.drawable.ic_sql));
tools.add(new Header("Design & IDE Tools"));
tools.add(new ListItem("Android Studio", R.drawable.ic_androidstudio));
tools.add(new ListItem("Visual Studio", R.drawable.ic_visual_studio));
tools.add(new ListItem("Genymotion", R.drawable.ic_genymotion));
tools.add(new ListItem("Ionic", R.drawable.ic_ionic));
tools.add(new Header("Office Tools"));
tools.add(new ListItem("MS Project", R.drawable.ic_project));
tools.add(new ListItem("MS Visio", R.drawable.ic_visio));
tools.add(new ListItem("MS Excel", R.drawable.ic_excel));
tools.add(new ListItem("MS Word", R.drawable.ic_word));
}
}
ListArrayAdapter.java
public class ListArrayAdapter extends ArrayAdapter<Tools> {
private LayoutInflater mInflater;
public enum RowType{ LIST_ITEM, HEADER_ITEM }
public ListArrayAdapter(Context context, List<Tools> tools){
super(context, 0, tools);
mInflater = LayoutInflater.from(context);
}
@Override
public int getViewTypeCount(){return RowType.values().length;}
@Override
public int getItemViewType(int pos){return getItem(pos).getViewType();}
private static final int TYPE_ITEM = 0;
private static final int TYPE_SEPARATOR = 1;
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
int rowType = getItemViewType(position);
View View;
if (convertView == null) {
holder = new ViewHolder();
switch (rowType) {
case TYPE_ITEM:
convertView = mInflater.inflate(R.layout.listview_item, null);
holder.View=getItem(position).getView(mInflater, convertView);
break;
case TYPE_SEPARATOR:
convertView = mInflater.inflate(R.layout.list_title, null);
holder.View=getItem(position).getView(mInflater, convertView);
break;
}
convertView.setTag(holder);
}
else
{
holder = (ViewHolder) convertView.getTag();
}
return convertView;
}
public static class ViewHolder {
public View View;
}
}
Tools.java
public interface Tools {
public int getViewType();
public View getView(LayoutInflater inflater, View convertView);
}
ListItem.java
public class ListItem implements Tools {
private final String str1;
private final int pic1;
public ListItem(String text1, int pic1) {
this.str1 = text1;
this.pic1 = pic1;
}
@Override
public int getViewType() {
return ListArrayAdapter.RowType.LIST_ITEM.ordinal();
}
@Override
public View getView(LayoutInflater inflater, View convertView) {
View view;
if (convertView == null) {
view = (View) inflater.inflate(R.layout.listview_item, null);
// Do some initialization
} else {
view = convertView;
}
TextView text1 = (TextView) view.findViewById(R.id.listText);
ImageView picture1 = (ImageView) view.findViewById(R.id.listIcon);
text1.setText(str1);
picture1.setImageResource(pic1);
return view;
}
}
Header.java
public class Header implements Tools {
private final String name;
public Header(String name) {
this.name = name;
}
@Override
public int getViewType() {
return ListArrayAdapter.RowType.HEADER_ITEM.ordinal();
}
@Override
public View getView(LayoutInflater inflater, View convertView) {
View view;
if (convertView == null) {
view = (View) inflater.inflate(R.layout.header, null);
// Do some initialization
} else {
view = convertView;
}
TextView text = (TextView) view.findViewById(R.id.separator);
text.setText(name);
return view;
}
}
解决方案
You are only populating your row widgets in the if (convertView == null) case. If convertView is not null, you are simply returning it unchanged, meaning it will have data from some prior position, not the position that is being requested.
IOW, you need to call methods like setText() and setImageResource() on every getView() call, to fill in the row's widgets with the data for the requested position.
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