来自 Web 服务的数据被正确接收，我通过在日志中打印所有值来检查它，所以显然我的后端服务没有错误。根据布局中列表的数组大小，数据也占据了空白空间，但我看不到数据，只有带有 TextView 的白屏。 LogCat 中没有错误。我不知道我做错了什么，将不胜感激。谢谢
这是我的 MainActivity，它有 AsyncTask 来获取数据。
swaop=(SwipeRefreshLayout)contentview.findViewById(R.id.layout_offerproducts);
rvofferproducts = (RecyclerView)findViewById(R.id.rv_offerproducts);
oparraylist = new ArrayList<B_OfferProducts>();
opadapter = new adapter_offerproducts(getApplicationContext(), oparraylist);
final RecyclerView.LayoutManager manager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
rvofferproducts.setLayoutManager(manager);
rvofferproducts.setItemAnimator(new DefaultItemAnimator());
rvofferproducts.setAdapter(opadapter);
isConnected = ConnectivityReceiver.isConnected();
if(isConnected)
{
new loadallofferproducts().execute();
}
//ASYNC TASK
public class loadallofferproducts extends AsyncTask<String, String, String>
{
@Override
protected String doInBackground(String... strings) {
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("OfferID", OfferID));
JSONObject jsonObject = jsonParser.makeHttpRequest(url_offerproducts, "POST", params);
try {
int success = jsonObject.getInt("success");
if(success == 1)
{
ophasharraylist = new ArrayList<HashMap<String, String>>();
offerproductsarray = jsonObject.getJSONArray("offerproducts");
for(int i = 0; i < offerproductsarray.length(); i++)
{
JSONObject opobj =offerproductsarray.getJSONObject(i);
String ProductId = opobj.getString("ProductID");
String ProductName = opobj.getString("ProductName");
String ProductPrice = "₹ " + opobj.getString("ProductPrice");
String ProductDP = "₹ " +opobj.getString("ProductDiscountP");
String ProductURL = opobj.getString("ProductPicURL");
String ProductDescription = opobj.getString("ProductDescription");
HashMap<String, String> map = new HashMap<String, String>();
B_OfferProducts b_offerProducts = new B_OfferProducts();
map.put("ProductID", ProductId);
map.put("ProductName", ProductName);
map.put("ProductPrice", ProductPrice);
map.put("ProductDiscountP", ProductDP);
map.put("ProductPicURL",ProductURL);
map.put("ProductDescription", ProductDescription);
ophasharraylist.add(map);
b_offerProducts.setProductPicURL(ophasharraylist.get(i).get("ProductPicURL").trim());
b_offerProducts.setProductName(ophasharraylist.get(i).get("ProductName").trim());
b_offerProducts.setProductPrice(ophasharraylist.get(i).get("ProductPrice").trim());
b_offerProducts.setProductDiscountP(ophasharraylist.get(i).get("ProductDiscountP").trim());
b_offerProducts.setProductDescription(ophasharraylist.get(i).get("ProductDescription").trim());
Log.d("OfferProducts",b_offerProducts.getProductName());
oparraylist.add(b_offerProducts);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
opadapter.notifyDataSetChanged();
}
}
}
这是我的适配器类。
public class adapter_offerproducts extends RecyclerView.Adapter<adapter_offerproducts.MyViewHolder>{
private List<B_OfferProducts> offerproductlist;
Context mcontext;
public class MyViewHolder extends RecyclerView.ViewHolder
{
public TextView pname, pprice, pdpricce, pdescription;
public ImageView pimg;
public MyViewHolder(View view)
{
super(view);
pname = (TextView)view.findViewById(R.id.rv_op_pname);
pprice = (TextView)view.findViewById(R.id.rv_op_pprice);
pdpricce = (TextView)view.findViewById(R.id.rv_op_pdprice);
pdescription = (TextView)view.findViewById(R.id.rv_op_pdescription);
pimg = (ImageView)view.findViewById(R.id.rv_op_img);
}
}
public adapter_offerproducts(Context context, List<B_OfferProducts> oplist )
{
mcontext = context;
this.offerproductlist = oplist;
}
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View itemview = LayoutInflater.from(parent.getContext()).inflate(R.layout.rv_container_offerproducts,parent,false);
return new MyViewHolder(itemview);
}
@Override
public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
B_OfferProducts b_offerProducts = new B_OfferProducts();
Picasso.get()
.load(b_offerProducts.getProductPicURL())
.into(holder.pimg);
holder.pname.setText(b_offerProducts.getProductName());
holder.pprice.setText(b_offerProducts.getProductPrice());
holder.pdpricce.setText(b_offerProducts.getProductDiscountP());
holder.pdescription.setText(b_offerProducts.getProductDescription());
}
@Override
public int getItemCount() {
return offerproductlist.size();
}
}
这是 RecyclerView 的我的容器
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="150dp"
android:layout_height="150dp"
android:id="@+id/rv_op_img"
android:contentDescription="ProductImage"/>
<TextView
android:id="@+id/rv_op_pname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="TextView"
app:layout_constraintStart_toEndOf="@+id/rv_op_img"
tools:layout_editor_absoluteY="16dp" />
<TextView
android:id="@+id/rv_op_pprice"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="TextView"
app:layout_constraintStart_toEndOf="@+id/rv_op_img"
tools:layout_editor_absoluteY="56dp" />
<TextView
android:id="@+id/rv_op_pdprice"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="TextView"
app:layout_constraintStart_toEndOf="@+id/rv_op_img"
tools:layout_editor_absoluteY="96dp" />
<TextView
android:id="@+id/rv_op_pdescription"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="TextView"
app:layout_constraintStart_toEndOf="@+id/rv_op_img"
tools:layout_editor_absoluteY="131dp" />
</android.support.constraint.ConstraintLayout>
这是我的 Activity 布局
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/layout_offerproducts"
tools:context="com.test.OfferProducts">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_marginTop="60dp"
android:layout_gravity="center"
android:layout_height="wrap_content"
android:orientation="vertical" >
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/rv_offerproducts">
</android.support.v7.widget.RecyclerView>
<TextView
android:id="@+id/textView4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Blah This IS TEXT" />
</LinearLayout>
</ScrollView>
最佳答案
您可能应该从传递给适配器的列表中获取您的 B_OfferProducts，即从列表 offerproductlist 中获取，而不是每次都创建一个对象。
无论您在 B_OfferProducts 类的构造函数中放入什么，您的项目都不会绑定(bind)到列表，这可能是数据未正确加载的原因。这些创建的对象将仅存在于 ViewHolder 中。
这意味着你应该更换
B_OfferProducts b_offerProducts = new B_OfferProducts();
在 onBindViewHolder() 中获取与列表中当前位置相关的对象，像这样:
B_OfferProducts b_offerProducts = offerproductlist.get(position)
希望对你有所帮助。干杯!
关于android - 数据在布局中创建并占据空白，但看不到，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50179240/