有人能解释我，如何实现？ 我有一个listview和footer的活动，包含一些元素（textview）。
使用自定义适配器构建的Listview。每个listview项都有很少的元素。我的问题是：当我点击某个listview的元素时，如何在自定义适配器中更改页脚中的textview？
很多！
/ ****我的适配器**** /
public class MyListAdapter extends ArrayAdapter<Product> implements UndoAdapter {
private final Context mContext;
private HashMap<Product, Integer> mIdMap = new HashMap<Product, Integer>();
ArrayList<Product> products = new ArrayList<Product>();
final int INVALID_ID = -1;
LayoutInflater lInflater;
String imagePath;
public MyListAdapter(Context context, int textViewResourceId, List<Product> prod) {
//super(context, textViewResourceId, prod);
super(prod);
lInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mContext = context;
for (int i = 0; i < prod.size(); i++) {
//add(prod.get(i));
mIdMap.put(prod.get(i),i);
}
}
@Override
public long getItemId(final int position) {
//return getItem(position).hashCode();
Product item = (Product) getItem(position);
return mIdMap.get(item);
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public View getView(final int position, View convertView, final ViewGroup parent) {
ViewHolder holder = null;;
Product p = getItem(position);
if (convertView == null) {
convertView = lInflater.inflate(R.layout.item, null);
//convertView.setBackgroundResource(R.drawable.rounded_corners);
int currentTheme = Utils.getCurrentTheme(convertView.getContext());
switch (currentTheme) {
case 0:
convertView.setBackgroundResource(R.drawable.rounded_corners);
break;
case 1:
convertView.setBackgroundResource(R.drawable.border);
break;
default:
convertView.setBackgroundResource(R.drawable.rounded_corners);
break;
}
holder = new ViewHolder();
holder.tvDescr = (TextView) convertView.findViewById(R.id.tvDescr);
holder.list_image = (ImageView) convertView.findViewById(R.id.list_image);
holder.products_amount = (TextView) convertView.findViewById(R.id.amountDigits);
holder.products_price = (TextView) convertView.findViewById(R.id.priceDigits);
holder.ivImage = (ImageView) convertView.findViewById(R.id.ivImage);
holder.unit = (TextView) convertView.findViewById(R.id.unit);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if(p.getProductImageBitmap() != null && p.getProductImageBitmap() != "") {
Log.d("PATH -- ", p.getProductImageBitmap());
ImageLoader imageLoader = ImageLoader.getInstance();
DisplayImageOptions options = new DisplayImageOptions.Builder().cacheInMemory(true)
.resetViewBeforeLoading(true)
.showImageForEmptyUri(R.drawable.ic_launcher)
.showImageOnFail(R.drawable.ic_launcher)
/*.showImageOnLoading(R.id.progress_circular)*/
.build();
imageLoader.displayImage(p.getProductImageBitmap(), holder.list_image, options);
} else {
holder.list_image.setImageResource(R.drawable.ic_launcher);
}
holder.tvDescr.setText(p.getProductName());
holder.ivImage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String deletedItem = getItem(position).getProductName();
MyListAdapter.this.remove(getItem(position));
if (MyListAdapter.this.getCount() > 0) {
Toast.makeText(mContext, deletedItem + " " + mContext.getString(R.string.deleted_item), Toast.LENGTH_SHORT).show();
MyListAdapter.this.notifyDataSetChanged();
} else {
Toast.makeText(mContext,mContext.getString(R.string.sklerolist_empty), Toast.LENGTH_SHORT).show();
}
}
});
//Функционал для большой картинки продукта
//открывается новое активити с большой картинкой
holder.list_image.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
imagePath = getItem(position).getProductImageBitmap();
if(imagePath != null && imagePath != "") {
Pattern normalPrice = Pattern.compile("^file");
Matcher m2 = normalPrice.matcher(imagePath);
if (m2.find()) {
Intent myIntent = new Intent(view.getContext(), ViewImage.class).putExtra("imagePath", imagePath);
view.getContext().startActivity(myIntent);
}
}
}
});
holder.products_price.setText(fmt(p.getProductPrice()));
holder.products_amount.setText(fmt(p.getProductAmount()));
holder.unit.setText(p.getProductUnit());
return convertView;
}
public static String fmt(double d){
if(d == (long) d)
return String.format("%d",(long)d);
else
return String.format("%s",d);
}
static class ViewHolder {
ImageView list_image;
TextView tvDescr;
TextView products_amount;
TextView products_price;
TextView unit;
ImageView ivImage;
ProgressBar circleProgress;
}
@NonNull
@Override
public View getUndoView(final int position, final View convertView, @NonNull final ViewGroup parent) {
View view = convertView;
if (view == null) {
//view = LayoutInflater.from(mContext).inflate(R.layout.undo_row, parent, false);
view = lInflater.inflate(R.layout.undo_row, parent, false);
}
return view;
}
@NonNull
@Override
public View getUndoClickView(@NonNull final View view) {
return view.findViewById(R.id.undo_row_undobutton);
}
public View getHeaderView(final int position, final View convertView, final ViewGroup parent) {
TextView view = (TextView) convertView;
//View view = convertView;
if (view == null) {
//view = (TextView) LayoutInflater.from(mContext).inflate(R.layout.list_header, parent, false);
//view = lInflater.inflate(R.layout.list_header, parent, false);
}
//view.setText(mContext.getString(R.string.header, getHeaderId(position)));
return view;
}
public long getHeaderId(final int position) {
return position / 10;
}
}
答案 0 :(得分：3)
您的ListView有一个监听列表元素上的点击事件。
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// Do something when a list item is clicked
}
但是如果你想将其他东西从适配器传回到Activity或包含Fragment和ListView的{{1}}，你应该创建一个简单的界面并将其设置为适配器的侦听器。之后，在适配器中设置行上的点击事件，并使用您自己的界面通知Adapter或Activity。
例如，您的界面定义如下
Fragment在您的public interface OnItemClickedCustomAdapter {
public void onClick(ItemPosition position);
}
课程中，您将拥有一名私人会员
Adapter以及用于设置侦听器的方法
private OnItemClickedCustomAdapter mListener;
从定义了public void setOnItemClickedCustomAdapter(OnItemClickedCustomAdapter listener){
this.mListener = listener;
}
的{{1}}或Activity开始，您的适配器设置完毕后，您就可以Fragment作为ListView参数，你去。您的活动现在将收听您的活动。要触发事件，只需从自定义适配器调用setOnItemClickedCustomAdapter即可。您可以将所需的数据传回this或mListener.onClick()，然后您可以直接访问Activity或Fragment，并可以更改它们。