[英]Why is Getter and Setter not working for Arraylist in Android
[英]Getter and setter not working as expected in recyclerview android
我從齊射請求中獲取json值。 我使用setter方法將這些值添加到列表中。 當我在適配器onBindViewholder()方法中檢索值並將其顯示在recyclerview結果中時,未按預期顯示:
下面的代碼引用了在MainActivity.java中向齊射請求和響應中的列表添加值:
private ProductsPojo pojo;
public static ProductsAdapter productsAdapter;
private List<ProductsPojo> pojoList;
pojo = new ProductsPojo();
pojoList = new ArrayList<>();
StringRequest request = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
// Log.d("Appet8","Products response:"+response.toString());
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray products = jsonObject.getJSONArray("products");
for (int i=0;i<products.length();i++) {
JSONObject product_object = products.getJSONObject(i);
String name = product_object.getString("name");
String price = product_object.getString("price");
String product_id = product_object.getString("id");
String sessionname = product_object.getString("sessionname");
String image = product_object.getString("image");
String categoryname = product_object.getString("categoryname");
pojo.setName(product_object.getString("name"));
pojo.setImage(product_object.getString("image"));
pojoList.add(pojo);
}
productsAdapter = new ProductsAdapter(pojoList,getApplicationContext());
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// Toast.makeText(getApplicationContext(),error.getMessage(), Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
// Posting parameters to login url
Map<String, String> params = new HashMap<String, String>();
params.put("customer_id", customer_id);
return params;
}
};
AppController.getInstance().addToRequestQueue(request,tag_request);
下面的代碼指的是在ProductFragment.java中將適配器設置為recyclerview:
private GridLayoutManager layoutManager;
private RecyclerView recyclerView;
recyclerView = (RecyclerView) view.findViewById(R.id.productList);
recyclerView.setHasFixedSize(true);
layoutManager = new GridLayoutManager(getActivity().getApplicationContext(),3);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(MainActivity.productsAdapter);
下面的代碼引用顯示值的適配器類ProductsAdapter.java:
public class ProductsAdapter extends RecyclerView.Adapter<ProductsAdapter.ProductsViewHolder> {
private List<ProductsPojo> productList;
private Context context;
public ProductsAdapter(List<ProductsPojo> productList,Context context) {
this.productList=productList;
this.context = context;
}
@Override
public ProductsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.
from(parent.getContext()).
inflate(R.layout.products_list, parent, false);
ProductsViewHolder holder = new ProductsViewHolder(view);
return holder;
}
@Override
public void onBindViewHolder(final ProductsViewHolder holder,final int position) {
final ProductsPojo pojo = productList.get(position);
Log.d("Appet8","Name:"+pojo.getName());
holder.vTitle.setText(pojo.getName());
holder.vTitle.setTypeface(MainActivity.font);
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
pojo.setSelected(!pojo.isSelected());
holder.itemView.setBackgroundColor(pojo.isSelected() ? Color.parseColor("#4D79CF08") : Color.parseColor("#2D6F6F6F"));
if(pojo.isSelected()) {
holder.selected.setVisibility(View.VISIBLE);
} else if(!pojo.isSelected()) {
holder.selected.setVisibility(View.GONE);
}
}
});
}
@Override
public int getItemCount() {
return productList.size();
}
public static class ProductsViewHolder extends RecyclerView.ViewHolder {
protected TextView vTitle;
protected ImageView image,selected;
protected CardView product_card;
public ProductsViewHolder(View v) {
super(v);
vTitle = (TextView) v.findViewById(R.id.title);
image = (ImageView) v.findViewById(R.id.product);
product_card = (CardView) v.findViewById(R.id.product_card);
selected = (ImageView) v.findViewById(R.id.selected);
}
}
}
這是我從截擊請求中得到的響應:
{
"products":[
{
"name":"Idli",
"price":"120",
"id":"Fi2mYuQA",
"sessionname":"Breakfast",
"image":"VCYwmSae2BShoshone_Falls-1200px.jpeg",
"categoryname":"Veg"
},
{
"name":"Meals123",
"price":"200",
"id":"bmF8Is1Y",
"sessionname":"Dinner",
"image":"sIe8JBFzaRstock-photo-115193575.jpg",
"categoryname":"Non Veg"
},
{
"name":"Dosa",
"price":"100",
"id":"e9sWHV4A",
"sessionname":"Breakfast",
"image":"j8nu4GpVa7Shoshone_Falls-1200px.jpeg",
"categoryname":"Veg"
},
{
"name":"Coca",
"price":"40",
"id":"0oJDfdCz",
"sessionname":"Cold Drinks",
"image":"LrkS8QpAs7Shoshone_Falls-1200px.jpeg",
"categoryname":"Veg"
},
{
"name":"ICe",
"price":"100",
"id":"2ykEgtSs",
"sessionname":null,
"image":"KtPX9C26oRShoshone_Falls-1200px.jpeg",
"categoryname":"Veg"
}
]
}
這是我得到的輸出。 項目名稱重復。
下面的代碼引用ProductsPojo.java:
public class ProductsPojo {
public String name;
public String image;
private boolean isSelected = false;
public void setName(String name) {
this.name = name;
}
public void setImage(String image) {
this.image = image;
}
public String getName() {
return name;
}
public String getImage() {
return image;
}
public void setSelected(boolean selected) {
isSelected = selected;
}
public boolean isSelected() {
return isSelected;
}
}
在我看來,您只能在這里創建一個ProductsPojo
實例:
pojo = new ProductsPojo();
然后在循環中,您繼續修改此實例,然后一次又一次地將其添加到列表中。 這樣,您最終得到的列表中的同一項目(最后一項)是響應中得到的對象數量的多少倍。
您想要做的可能是每次都在for循環的開頭創建一個新的ProductsPojo
,如下所示:
for (int i=0;i<products.length();i++) {
ProductsPojo pojo = new ProductsPojo();
JSONObject product_object = products.getJSONObject(i);
String name = product_object.getString("name");
String price = product_object.getString("price");
String product_id = product_object.getString("id");
String sessionname = product_object.getString("sessionname");
String image = product_object.getString("image");
String categoryname = product_object.getString("categoryname");
pojo.setName(product_object.getString("name"));
pojo.setImage(product_object.getString("image"));
pojoList.add(pojo);
}
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