滚动时，Android Listview重置更改

生也有涯，知也无涯。这篇文章主要讲述滚动时，Android Listview重置更改相关的知识，希望能为你提供帮助。
我正在使用带有自定义适配器的ListFragment。
我的适配器有一个textview和一个带箭头的隐藏imageview。当用户选择项目时，箭头显示并且背景颜色发生变化。但是，当用户滚动列表时，所有更改都将恢复为默认值。
我应该怎么做才能解决这些变化？
编辑：
我的适配器类..

public class PropriedadeAdapter extends BaseAdapter { private Context context; private List< Propriedades> prop; public PropriedadeAdapter(Context context, List< Propriedades> prop) { this.context = context; this.prop = prop; }public int getCount() { return prop.size(); }public Object getItem(int position) { return prop.get(position); }public long getItemId(int position) { return position; }public View getView(int position, View convertView, ViewGroup parent) { // Recupera o produto da posi??o atual Propriedades p = prop.get(position); // Layout XML int arquivoLayout = R.layout.lista_prop; LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); View v = inflater.inflate(arquivoLayout, null); // Atualiza o valor do Text para o nome do produto TextView textNome = (TextView) v.findViewById(R.id.nome); textNome.setText(p.getNome()); return v; } }

我的片段课..

public class frag_lista extends ListFragment{ImageView ultimoItem = null; @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); ArrayList< Propriedades> props = new ArrayList< Propriedades> (); for(int i = 0; i < 50; i++) { Propriedades prop = new Propriedades(); prop.setNome("FRUTA "+i); props.add(prop); } setListAdapter(new PropriedadeAdapter(this.getActivity(),props)); }@Override public void onListItemClick(ListView l, View v, int position, long id) { ImageView seta = (ImageView)v.findViewById(R.id.imgSeta); seta.setVisibility(0); LinearLayout linha = (LinearLayout)v.findViewById(R.id.linha); linha.setBackgroundColor(Color.GRAY); if(ultimoItem != null) { ultimoItem.setVisibility(4); } ultimoItem = seta; }}

【滚动时，Android Listview重置更改】我该怎么做才能坚持onListItemClick方法的变化????
答案根据您的评论，我认为您没有正确使用适配器。
Adapter提供ListView自动调用的方法。
您应该在内存中保留选定的索引，并在每次调用getView(...)方法时恢复View状态（从position参数jusging）。
查找有关ListView和Adapter的教程。
编辑：
请注意，我没有测试代码，但它可能是这样的：

// TeddyBearFr: Class name typically starts with a capital letter! Frag_lista, not frag_lista public class frag_lista extends ListFragment{ImageView ultimoItem = null; @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); ArrayList< Propriedades> props = new ArrayList< Propriedades> (); for(int i = 0; i < 50; i++) { Propriedades prop = new Propriedades(); prop.setNome("FRUTA "+i); props.add(prop); } setListAdapter(new PropriedadeAdapter(this.getActivity(),props)); }@Override public void onListItemClick(ListView l, View v, int position, long id) {// TeddyBearFr: notify the adapter ( (PropriedadeAdapter) this.getListAdapter() ).onListItemClick(position); // TeddyBearFr: your last item must be managed in the getView(...) method of the Adapter //if(ultimoItem != null) //{ //ultimoItem.setVisibility(4); // TeddyBearFr: don't use integer like this, use android constants! View.INVISIBLE //} //ultimoItem = seta; }}public class PropriedadeAdapter extends BaseAdapter { private final static String TAG = "PropriedadeAdapter"; private Context context; private List< Propriedades> prop; private Set< Integer> mSelectedItemsPosition; public PropriedadeAdapter(Context context, List< Propriedades> prop) { this.context = context; this.prop = prop; // TeddyBearFr: set to store selected indexes this.mSelectedItemsPosition = new HashSet< Integer> (); }public int getCount() { return prop.size(); }public Object getItem(int position) { return prop.get(position); }public long getItemId(int position) { return position; }public View getView(int position, View convertView, ViewGroup parent) { Log.d(TAG, "getView(position=" + position + ", convertView=" + convertView + ", parent=" + parent + ")" ); // Recupera o produto da posi??o atual Propriedades p = prop.get(position); // TeddyBearFr: use existing view if exist ; otherwise create a new one View v; if( convertView == null ){ // Layout XML int arquivoLayout = R.layout.lista_prop; LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = inflater.inflate(arquivoLayout, null); } else{ v = convertView; }// Atualiza o valor do Text para o nome do produto TextView textNome = (TextView) v.findViewById(R.id.nome); textNome.setText(p.getNome()); // TeddyBearFr: update view according its selection state ImageView seta = (ImageView)v.findViewById(R.id.imgSeta); boolean isViewSelected = this.mSelectedItemsPosition.contains(position); int visibility = ( isViewSelected ? VIEW.VISIBLE : VIEW.GONE ); seta.setVisibility(visibility); LinearLayout linha = (LinearLayout)v.findViewById(R.id.linha); linha.setBackgroundColor( isViewSelected ? Color.GRAY : Color.RED ); if( position == getCount()-1 ){ // perform special processes on the last item of the list if needed }return v; }// TeddyBearFr: callback when click public void onListItemClick(int position){ Log.d(TAG, "onListItemClick(position=" + position + ")"); // update selected index data // Note that I haven't tested if it works. Because native integer "position" will be wrapped in Integer object, there's a chance that the Set compares the references on objects instead of their value if( this.mSelectedItemsPosition.contains(position) ){ this.mSelectedItemsPosition.remove(position); } else{ this.mSelectedItemsPosition.add(position); }// ask the list to be refreshed -> you'll see that getView() will be called only for each displayed view this.notifyDataSetChanged(); }}

另一答案convertView有两个状态，它们是null而不是null。您的问题发生是因为eveytime yout getView（）调用新的布局inflater实例正在初始化。仅当convertView为null时才初始化inflater。

public View getView(int position, View convertView, ViewGroup parent) {Propriedades p = prop.get(position); int arquivoLayout = R.layout.lista_prop; View v; if (convertView==null){ v = inflater.inflate(arquivoLayout, null); } else { v = convertView; }// Atualiza o valor do Text para o nome do produto TextView textNome = (TextView) v.findViewById(R.id.nome); textNome.setText(p.getNome()); return v; }

另外，请记住将inflater声明为字段。

LayoutInflater inflater = null;

并在构造函数中初始化它。

public PropriedadeAdapter(Context context, List< Propriedades> prop) { this.context = context; this.prop = prop; inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); }