我想更改数量textview以反映特定商品的数量。但是在单击add和sub按钮时,setText()函数似乎不起作用。这是我的适配器类
public class ItemAdapter extends ArrayAdapter<String>{
Context context;
int[] images,rate,quant;
String[] names;
ImageButton add, sub;
ViewHolder holder; // Since will be accessed inside onclick
Integer count1=0;
HashMap<String,Integer> positiveNumbers = new HashMap<String,Integer>();
Integer count=0;
static class ViewHolder {
public TextView textView;
public ImageView imageView;
public TextView number;
public TextView rates;
public String uniqueKey;
}
public ItemAdapter(Context c, String[] items, int quantity[], int[] rate, int[] img) {
// TODO Auto-generated constructor stub
super(c, R.layout.item_fooditems, R.id.tvitemname, items);
this.context = c;
this.images = img;
this.names = items;
this.rate=rate;
this.quant=quantity;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View row = convertView;
// reuse views
if (row == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.item_fooditems, parent, false);
ViewHolder viewHolder = new ViewHolder();
viewHolder.imageView = (ImageView) row.findViewById(R.id.ivimage);
viewHolder.textView = (TextView) row.findViewById(R.id.tvitemname);
viewHolder.number = (TextView)row.findViewById(R.id.tvquantity);
viewHolder.rates = (TextView)row.findViewById(R.id.tvprice);
viewHolder.uniqueKey = String.valueOf(position);
add = (ImageButton) row.findViewById(R.id.bincrement);
add.setTag(position);
sub = (ImageButton) row.findViewById(R.id.bdecrement);
sub.setTag(position);
row.setTag(viewHolder);
}
holder = (ViewHolder) row.getTag(); //keeping one global memory
holder.imageView.setImageResource(images[position]);
holder.textView.setText(names[position]);
holder.rates.setText(Integer.toString(rate[position]));
holder.number.setText(Integer.toString(quant[position]));
holder.number.setText("x");
add.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
quant[position]=quant[position]+1;
count1 +=1;
//holder.number.setText(Integer.toString(quant[position]));
holder.number.setText(count1.toString());
Toast.makeText(context, Integer.toString(quant[position]), Toast.LENGTH_SHORT).show();
Log.d("Quantity",Integer.toString(quant[position]));
positiveNumbers.put(holder.uniqueKey,count); //Key -> String.valueOf(position) and Value -> int count
}
});
sub.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
quant[position]--;
Toast.makeText(context, Integer.toString(quant[position]), Toast.LENGTH_SHORT).show();
holder.number.setText(Integer.toString(quant[position]));
positiveNumbers.put(holder.uniqueKey,count); //Key -> String.valueOf(position) and Value -> int count
}
});
return row;
}
public HashMap<String, Integer> getPositiveNumbers()
{
return positiveNumbers;
}
}
需要进行哪些修改?
答案 0 :(得分:1)
首先,您应该使用所需的所有值创建自定义模态类,而不是采用这些单独的数组。例如,在您的情况下,它将是这样的。
public class Item {
private String itemName = "";
private int quantity;
private int rate;
private int image;
public String getItemName() {
return itemName;
}
public void setItemName(String itemName) {
this.itemName = itemName;
}
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
public int getRate() {
return rate;
}
public void setRate(int rate) {
this.rate = rate;
}
public int getImage() {
return image;
}
public void setImage(int image) {
this.image = image;
}
}
现在将这个模态类传递给你的适配器构造函数。这就是你在getView()中设置值的方法
Item item=itemList.get(position); //here itemList is the list you are passing to your adapter.
holder.imageView.setImageResource(item.getImage());
holder.textView.setText(item.getItemName());
holder.rates.setText(String.valueOf(item.getRate()));
holder.number.setText(String.valueOf(item.getQuantity()));
现在进入您的添加/子点击监听器,无需在添加/子点击监听器内设置数量TextView的文本。您可以在更新itemList的相应索引处的数量值后通知您的适配器。例如。为了增加数量,你可以做这样的事情。
add.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Item item=itemList.get(position);// getting the item at particular position
item.setQuantity(item.getQuantity()+1);// incrementing item quantity by 1
itemList.set(position,item);// updating the itemList to that new item with incremented quantity
notifyDataSetChanged();//notifying the adapter
}
});
您可以为减去数量onClickListener()做同样的事情。
sub.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Item item=itemList.get(position);//getting the item at particular position
item.setQuantity(item.getQuantity()-1);//decrementing item quantity by 1
itemList.set(position,item);// updating the itemList to that new item with decremented quantity
notifyDataSetChanged();//notifying the adapter
}
});
这肯定有用。在处理ListView / RecyclerView的自定义适配器时,最好还是维护单个列表而不是多个数组。
答案 1 :(得分:0)
您必须在添加和子按钮点击代码后调用 notifyDataSetChanged(); 。
添加
add.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
quant[position]=quant[position]+1;
count1 +=1;
//holder.number.setText(Integer.toString(quant[position]));
holder.number.setText(count1.toString());
Toast.makeText(context, Integer.toString(quant[position]), Toast.LENGTH_SHORT).show();
Log.d("Quantity",Integer.toString(quant[position]));
positiveNumbers.put(holder.uniqueKey,count); //Key -> String.valueOf(position) and Value -> int count
notifyDataSetChanged();
}
});
对于Sub
sub.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
quant[position]--;
Toast.makeText(context, Integer.toString(quant[position]), Toast.LENGTH_SHORT).show();
holder.number.setText(Integer.toString(quant[position]));
positiveNumbers.put(holder.uniqueKey,count); //Key -> String.valueOf(position) and Value -> int count
notifyDataSetChanged();
}
});
希望它有所帮助!!