Question

您好我的listView有问题我的OnItemClick方法有错误

FATAL EXCEPTION：main java.lang.ClassCastException：com.example.dell.app3.Product无法强制转换为java.util.HashMap

private void showProduct(String json){
        JSONObject jsonObject = null;
        ArrayList<Product> productList = new ArrayList<>();
        try {
            JSONArray result = new JSONArray(json);
            for(int i = 0; i<result.length(); i++){
                JSONObject jo = result.getJSONObject(i);
                String name = jo.getString("Nom");
                String ref = jo.getString("Reference");
                String image1 = "http://aaaa.com/Scripts/images/"+jo.getString("image")+".jpg";
                Product product = new Product();
                product.setName(name);
                product.setRef(ref);
                product.setImageUrl(image1);
                productList.add(product);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
        adapter = new CustomArrayAdapter(getContext(), productList);
        listView.setAdapter(adapter);
    }

OnItemClick方法

public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Intent intent = new Intent(getActivity().getApplicationContext(), ViewProduct.class);
        HashMap<String, String> map = (HashMap) parent.getItemAtPosition(position);
        String tid = map.get("ref").toString();
        intent.putExtra("ref", tid);
        startActivity(intent);
    }

我的inputSearch

也有错误

inputSearch.addTextChangedListener(new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
                ((CustomArrayAdapter) ProduitsFragment.this.adapter).getFilter().filter(cs);
            }
            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                                          int arg3) {
            }
            @Override
            public void afterTextChanged(Editable arg0) {
            }
        });

product.java

public class Product {
    String name;
    String ref;
    String imageUrl;

    public String getName() {
        return name;
    }
    public String getRef() {
        return ref;
    }
    public String getImageUrl() {
        return imageUrl;
    }
    public void setName(String name) {
        this.name = name;
    }
    public void setRef(String ref) {
        this.ref = ref;
    }
    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }
}

Answer 1

而不是

HashMap<String, String> map = (HashMap) parent.getItemAtPosition(position);
    String tid = map.get("ref").toString();

将其更改为

Product prod =  (Product)parent.getItemAtPosition(position);
    String tid = prod.getRef();

Answer 2

试试这个

宣布全球

  ArrayList<Product> productList = new ArrayList<>();

将onItemClick替换为

public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Intent intent = new Intent(getActivity().getApplicationContext(), ViewProduct.class);
        // get item from list @position
        Product product = (Product)productList.get(position);
        String tid = product.getRef();
        intent.putExtra("ref", tid);
        startActivity(intent);
    }

适用于您的Filter功能：

inputSearch.addTextChangedListener(new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
                 // global object of custom adapter
                 customArrayAdapter.getFilter().filter(cs.toString());   
            }
            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                                          int arg3) {
            }
            @Override
            public void afterTextChanged(Editable arg0) {
            }
        });

要过滤功能，请尝试

customArrayAdapter.getFilter().filter(cs);

而不是

((CustomArrayAdapter) ProduitsFragment.this.adapter).getFilter().filter(cs);

有关详情，请参阅：Custom Listview Adapter with filter Android

Answer 3

你正在从Hashmap中获取值。在你的代码中是excption.Get来自Product Mode.Which是一个对象。试试代码

public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent(getActivity().getApplicationContext(), ViewProduct.class);
            Product product = (Product)parent.getItemAtPosition(position);
            String tid = product.getRef();
            intent.putExtra("ref", tid);
            startActivity(intent);
        }

Answer 4

而不是onItemClick（）中的父级使用视图

HashMap<String, String> map = (HashMap) view.getItemAtPosition(position);

如何在列表视图中使用OnItemClick方法？

4 个答案: