Java 如何在单击按钮时更改列表项中的文本视图
我想更改我的数量文本视图以反映特定项目的数量。但是单击add和sub按钮时,setText()函数似乎不起作用。这是我的适配器类Java 如何在单击按钮时更改列表项中的文本视图,java,android,listview,button,onclicklistener,Java,Android,Listview,Button,Onclicklistener,我想更改我的数量文本视图以反映特定项目的数量。但是单击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; // Si
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;
}
}
公共类ItemAdapter扩展了ArrayAdapter{
语境;
int[]图像,速率,数量;
字符串[]名称;
图像按钮添加,子;
ViewHolder;//因为将在onclick内访问
整数count1=0;
HashMap positiveEnumbers=新HashMap();
整数计数=0;
静态类视图持有者{
公共文本视图文本视图;
公共影像视图;
公共文本视图编号;
公共文本浏览率;
公共字符串唯一密钥;
}
公共项适配器(上下文c、字符串[]项、整数数量[]、整数[]速率、整数[]img){
//TODO自动生成的构造函数存根
super(c,R.layout.item_fooditems,R.id.tviitemname,items);
this.context=c;
这个。图像=img;
this.names=项目;
这个比率=比率;
这个.quant=数量;
}
@凌驾
公共视图getView(最终整数位置、视图转换视图、视图组父视图){
//TODO自动生成的方法存根
视图行=转换视图;
//重用视图
if(行==null){
LayoutFlater充气器=(LayoutFlater)上下文
.getSystemService(上下文布局\充气机\服务);
行=充气机。充气(R.layout.item_fooditems,父项,false);
ViewHolder ViewHolder=新ViewHolder();
viewHolder.imageView=(imageView)row.findviewbyd(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(位置);
add=(ImageButton)row.findViewById(R.id.bincrement);
add.setTag(位置);
sub=(ImageButton)row.findViewById(R.id.b增量);
sub.setTag(位置);
row.setTag(viewHolder);
}
holder=(ViewHolder)row.getTag();//保留一个全局内存
holder.imageView.setImageResource(图像[位置]);
holder.textView.setText(名称[位置]);
holder.rates.setText(Integer.toString(rate[position]);
holder.number.setText(Integer.toString(quant[position]);
持有人编号:setText(“x”);
add.setOnClickListener(新的OnClickListener(){
@凌驾
公共void onClick(视图v){
//TODO自动生成的方法存根
数量[位置]=数量[位置]+1;
count1+=1;
//holder.number.setText(Integer.toString(quant[position]);
holder.number.setText(count1.toString());
Toast.makeText(上下文,Integer.toString(quant[position]),Toast.LENGTH\u SHORT.show();
Log.d(“数量”,整数.toString(数量[位置]);
positiveEnumbers.put(holder.uniqueKey,count);//Key->String.valueOf(position)and Value->int count
}
});
sub.setOnClickListener(新的OnClickListener(){
@凌驾
公共void onClick(视图v){
//TODO自动生成的方法存根
数量[位置]——;
Toast.makeText(上下文,Integer.toString(quant[position]),Toast.LENGTH\u SHORT.show();
holder.number.setText(Integer.toString(quant[position]);
positiveEnumbers.put(holder.uniqueKey,count);//Key->String.valueOf(position)and Value->int count
}
});
返回行;
}
公共HashMap GetPositionEnumbers()
{
返回正枚举数;
}
}
需要进行哪些修改?只需调用notifyDataSetChanged()在添加和子按钮后单击代码 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();
}
});
希望能帮上忙 首先,您不应该使用这些单独的数组,而应该使用所需的所有值创建一个定制的模态类。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;
}
}
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
}
});
现在将这个模态类传递给适配器构造函数
现在来到添加/分点击监听器,不需要在添加/分点击监听器中设置数量文本视图的文本。您只需在更新itemList对应索引处的quantity值后通知适配器即可。为了增加数量,你可以这样做
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;
}
}
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
}
});
对于减去数量onClickListener(),可以执行相同的操作
这肯定会奏效。另外,在处理ListView/RecyclerView的自定义适配器时,最好维护一个列表而不是多个数组。没有帮助。和以前一样,我可以看到值正在更改,但textView没有。很抱歉响应太晚。但是itemList不是未定义的吗?itemList应该是/做什么?itemList是您将传递给适配器的列表,它将充当ListView的数据源。您将使用此arrayList(即itemList)将数据膨胀到ListView行。类型不匹配:无法从HashMap转换为ItemModel在get(位置)处出错itemList不是HashMap。它基本上是一个类似列表itemList=new ArrayList()的ArrayList;在初始化构造函数时,只需将其传递给适配器构造函数。如果你仍然没有得到,让我知道我会更新更多的代码行的答案。