Question

我正在尝试从Adapter类本身刷新listView，但它并不令人耳目一新，不知道错误在哪里。

public class DeliveryListAdapter extends BaseAdapter
{
DeliveryListAdapter ald;
Context ct;
private List<DeliveryListBean> deliveryListBeans;
SharedPreferences companyName;

public DeliveryListAdapter(Context ct,List<DeliveryListBean> deliveryListBeans)
{
    this.ct=ct;
    this.deliveryListBeans=deliveryListBeans;
}
@Override
public int getCount() {
    return deliveryListBeans.size();
}

private void updateResults(List<DeliveryListBean> dlb)
{
    deliveryListBeans=dlb;
    notifyDataSetChanged();
}
//I skipped code for inflating because it is working fine.
delivered.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String serverURL= PathUrls.pathUrl+"evs_updatedeliverystatus.php?db="+companyName.getString("companyName","")+"&invoiceid="+dlb.getInvoiceNo()+"&deliverystatus=2";
            JsonObjectRequest jsonArrayRequest=new JsonObjectRequest(serverURL, new Response.Listener<JSONObject>() {
                @Override
                public void onResponse(JSONObject response) {
                    if (response.length()>0)
                    {
                        ald=new DeliveryListAdapter(ct,deliveryListBeans);
                        VolleyLog.v("update delivery list: %n %s ", response.toString());
                        try{
                            int status = response.getInt("status");
                            if (status==1)
                            {
                                Log.d("updated delivery",response.toString());
                                ald.updateResults(deliveryListBeans);
                                Toast.makeText(ct, "Delivery Successful", Toast.LENGTH_SHORT).show();
                            }
                            else if (status==0)
                            {
                                Toast.makeText(ct, "Delivery Has been failed", Toast.LENGTH_LONG).show();
                            }
                        }catch (JSONException e)
                        {
                         e.printStackTrace();
                        }
                    }

                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    VolleyLog.e("Error DeliveryList:%n %s ", error);
                    Toast.makeText(ct,"NetworkError Not Responding", Toast.LENGTH_SHORT).show();
                }
            });
            //Toast.makeText(ct, "companyName"+companyName.getString("companyName","").toString(), Toast.LENGTH_LONG).show();
            VolleySingleton.getsInstance().getRequestQueue().add(jsonArrayRequest);
        }
    });

我正在使用setOnclickListner来传递按钮来更新状态。状态正在更新，但单击交付按钮时列表不会刷新。

Answer 1

正如我在评论中所说，你搞砸了参考资料。见下面的代码：

private void updateResults(List<DeliveryListBean> dlb) {
    deliveryListBeans=dlb;
    notifyDataSetChanged();
}

您在此处将新列表分配给上一个列表，以便更改参考。适配器永远不会得到通知导致适配器具有先前的引用。所以解决方案有两种情况：如果您想要旧数据，那么如果您只需要新数据，则需要第二个：

 private void updateResults(List<DeliveryListBean> dlb) {
    deliveryListBeans.addAll(dlb);
    notifyDataSetChanged();
}


 private void updateResults(List<DeliveryListBean> dlb) {
    deliveryListBeans.clear();
    deliveryListBeans.addAll(dlb);
    notifyDataSetChanged();
}

Answer 2

为什么要创建新的适配器？

 DeliveryListAdapter   ald=new DeliveryListAdapter(ct,deliveryListBeans);

我认为您应该只更新deliveryListBeans

并使用ADM用户的这种方法。

 private void updateResults(List<DeliveryListBean> dlb) {
deliveryListBeans.clear();
deliveryListBeans.addAll(dlb);
notifyDataSetChanged();

}

我不认为你使用'回复'。您只需检查此var＆lt;中的状态 - 它是来自您服务器的数据

Answer 3

我找到了另一种方法。我刚刚从position删除了list，错误就是创建了新对象 ald=new DeliveryListAdapter(ct,deliveryListBeans); 你不必创建任何新对象。我做的是

if (status==1)
{
Log.d("updated delivery",response.toString());
deliveryListBeans.remove(position);
notifyDataSetChanged();
Toast.makeText(ct, "Delivery Successful", Toast.LENGTH_SHORT).show();
}

即使在调用notifyDataSetChanged（）之后，列表视图也不会刷新

3 个答案: