我有一个有12行的ListView。每个行项都包含一个ImageView和两个TextView。 ImageViews＆＃39;可见性都设置为INVISIBLE。当我单击一行时，我将ImageView的可见性更改为VISIBLE。
所以，我点击第一行，它的ImageView变得可见，这很好。但是，当我滚动ListView时，我发现其他行＆＃39; ImageViews也变得可见。我已经做了很多搜索，发现这是由于回收视图，因为我使用的是ViewHolder模式。
我已查看以下链接
但是还没能在我的代码中实现它。老实说，我不知道怎么做。以下是我的相关代码
listview_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:gravity="center_vertical"
android:background="@color/frame_background"
android:padding="5dp"
>
<!-- the innner view - provides the white rectangle -->
<RelativeLayout android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/frame" >
<!-- the icon view -->
<ImageView android:id="@+id/ivIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="5dp"
android:scaleType="fitXY"
android:layout_alignParentLeft="true"
android:visibility="invisible"
/>
<!-- the container view for the title and description -->
<RelativeLayout android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/ivIcon"
android:layout_centerVertical="true"
>
<!-- the title view -->
<TextView android:id="@+id/tvTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="@android:style/TextAppearance.Medium" />
<!-- the description view -->
<TextView android:id="@+id/tvDescription"
android:layout_below="@id/tvTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="@android:style/TextAppearance.Small" />
</RelativeLayout>
</RelativeLayout>
</RelativeLayout>
ListViewItem.java
public class ListViewItem {
public final String title; // the text for the ListView item title
public final String description; // the text for the ListView item description
public final int drawableRef; //Ref to drawable so Picassco can load it
public boolean visible;
public ListViewItem(int drawableRef, String title, String description) {
this.drawableRef=drawableRef;
this.title = title;
this.description = description;
}
public void setVisible(boolean value)
{
visible = value;
}
public boolean getVisible()
{
return visible;
}
}
ListViewDemoAdapter.java
public class ListViewDemoAdapter extends ArrayAdapter<ListViewItem> {
public ListViewDemoAdapter(Context context, List<ListViewItem> items) {
super(context, R.layout.listview_item,items);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if(convertView == null) {
// inflate the GridView item layout
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.listview_item, parent, false);
// initialize the view holder
viewHolder = new ViewHolder();
viewHolder.ivIcon = (ImageView) convertView.findViewById(R.id.ivIcon);
//viewHolder.ivIcon.setVisibility(View.INVISIBLE);
viewHolder.tvTitle = (TextView) convertView.findViewById(R.id.tvTitle);
viewHolder.tvDescription = (TextView) convertView.findViewById(R.id.tvDescription);
convertView.setTag(viewHolder);
} else {
// recycle the already inflated view
viewHolder = (ViewHolder) convertView.getTag();
}
if(position==ListViewDemoFragment.getSelectedPosition())
{
viewHolder.ivIcon.setVisibility(View.VISIBLE);
}
// update the item view
ListViewItem item = getItem(position);
//viewHolder.ivIcon.setImageDrawable(item.icon);
Picasso.with(getContext()).load(item.drawableRef).into(viewHolder.ivIcon);
viewHolder.tvTitle.setText(item.title);
viewHolder.tvDescription.setText(item.description);
return convertView;
}
private static class ViewHolder {
ImageView ivIcon;
TextView tvTitle;
TextView tvDescription;
}
}
ListViewDemoFragment.java
public class ListViewDemoFragment extends ListFragment {
private static List<ListViewItem> mItems; // ListView items list
private static int mSelectedItem=-1;
private static ListViewDemoAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// initialize the items list
mItems = new ArrayList<ListViewItem>();
Resources resources = getResources();
mItems.add(new ListViewItem(R.drawable.harley1, "TITLE 1", "DESCRIPTION 1"));
mItems.add(new ListViewItem(R.drawable.harley2, "TITLE 2", "DESCRIPTION 2"));
mItems.add(new ListViewItem(R.drawable.harley3, "TITLE 3", "DESCRIPTION 3"));
mItems.add(new ListViewItem(R.drawable.harley4, "TITLE 4", "DESCRIPTION 4"));
mItems.add(new ListViewItem(R.drawable.harley5, "TITLE 5", "DESCRIPTION 5"));
mItems.add(new ListViewItem(R.drawable.harley6, "TITLE 6", "DESCRIPTION 6"));
mItems.add(new ListViewItem(R.drawable.harley7, "TITLE 7", "DESCRIPTION 7"));
mItems.add(new ListViewItem(R.drawable.harley8, "TITLE 8", "DESCRIPTION 8"));
mItems.add(new ListViewItem(R.drawable.harley9, "TITLE 9", "DESCRIPTION 9"));
mItems.add(new ListViewItem(R.drawable.harley10, "TITLE 10", "DESCRIPTION 10"));
mItems.add(new ListViewItem(R.drawable.harley11, "TITLE 11", "DESCRIPTION 11"));
mItems.add(new ListViewItem(R.drawable.harley12, "TITLE 12", "DESCRIPTION 12"));
// initialize and set the list adapter
adapter = new ListViewDemoAdapter(getActivity(), mItems);
setListAdapter(adapter);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// remove the dividers from the ListView of the ListFragment
getListView().setDivider(null);
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// retrieve theListView item
ListViewItem item = mItems.get(position);
mSelectedItem = position;
adapter.notifyDataSetChanged();
// do something
Toast.makeText(getActivity(), item.title, Toast.LENGTH_SHORT).show();
}
public static int getSelectedPosition()
{
return mSelectedItem;
}
public static List<ListViewItem> getList()
{
return mItems;
}
public static ListViewDemoAdapter getAdapter()
{
return adapter;
}
}
我想我需要修改我的ListViewItem.java和我的适配器，但是在实现我看到的解决方案时遇到了麻烦。
修改
ListViewItem.java
public boolean visible = false;
public ListViewItem(int drawableRef, String title, String description) {
//this.icon = Resources.getSystem().getDrawable(drawableRef);
//this.icon = icon;
this.drawableRef=drawableRef;
this.title = title;
this.description = description;
}
public void setVisible(boolean value)
{
visible = value;
}
public boolean getVisible()
{
return visible;
}
ListViewDemoFragment onClick方法更改
public void onListItemClick(ListView l, View v, int position, long id) {
// retrieve theListView item
ListViewItem item = mItems.get(position);
mSelectedItem = position;
item.setVisible(true);
adapter.notifyDataSetChanged();
// do something
Toast.makeText(getActivity(), item.title, Toast.LENGTH_SHORT).show();
}
getView（）函数更改
else {
// recycle the already inflated view
viewHolder = (ViewHolder) convertView.getTag();
}
ListViewItem item = getItem(position);
if(position==ListViewDemoFragment.getSelectedPosition())
{
if(item.getVisible()==true) {
viewHolder.ivIcon.setVisibility(View.VISIBLE);
}
}
// update the item view
//viewHolder.ivIcon.setImageDrawable(item.icon);
Picasso.with(getContext()).load(item.drawableRef).into(viewHolder.ivIcon);
viewHolder.tvTitle.setText(item.title);
viewHolder.tvDescription.setText(item.description);
return convertView;
答案 0 :(得分：0)
由于您有boolean visible来记录状态，因此没有必要这样做：
if(position==ListViewDemoFragment.getSelectedPosition())
{
if(item.getVisible()==true) {
viewHolder.ivIcon.setVisibility(View.VISIBLE);
}
}
让数据确定ImageView的可见度。将以下代码写入getView
ListViewItem item = getItem(position);
if (item.getVisible()) {
viewHolder.ivIcon.setVisibility(View.VISIBLE);
} else {
viewHolder.ivIcon.setVisibility(View.INVISIBLE);
}