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我正在开发 android 中的应用程序。我有这段代码，我尝试将它与 volley 一起使用，以便我可以加载 json 并使用 json 将项目添加到列表中，但我总是做错了......

package com.hmkcode.android;

import java.util.ArrayList;
import android.os.Bundle;
import android.app.ListActivity;

public class MainActivity extends ListActivity {

public void onCreate(Bundle icicle) {
    super.onCreate(icicle);

    // 1. pass context and data to the custom adapter
    MyAdapter adapter = new MyAdapter(this, generateData());

    //2. setListAdapter
    setListAdapter(adapter);
}

private ArrayList<Item> generateData(){
    ArrayList<Item> items = new ArrayList<Item>();
    items.add(new Item("Item 1","First Item on the list"));
    items.add(new Item("Item 2","Second Item on the list"));
    items.add(new Item("Item 3","Third Item on the list"));

    return items;
}

}

我试图像这样实现它，但是我在 onResponse 中设置的静态项目没有显示，而且当我尝试点击这些项目时，应用程序最终崩溃

public void onCreate(Bundle icicle) {
    super.onCreate(icicle);

    // 1. pass context and data to the custom adapter
    MyAdapter adapter = new MyAdapter(this, generateData());

    //2. setListAdapter
    setListAdapter(adapter);
}

private ArrayList<Item> generateData(){
    ArrayList<Item> items = new ArrayList<Item>();
    items.add(new Item("Item 1","First Item on the list"));


    RequestQueue queue = Volley.newRequestQueue(this);
    String url = "http://echo.jsontest.com/just/test/values/two";

    JsonObjectRequest jsObjRequest = new JsonObjectRequest(Method.GET, url, null, new Response.Listener<JSONObject>() {

        @Override
        public void onResponse(JSONObject response) {
           //my loop here
             items.add(new Item("Item 1","this is just a sample "));
           }
 }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            // TODO Auto-generated method stub

        }
    });

    queue.add(jsObjRequest);


    return items;
}

编辑：

    11-09 13:25:00.465:E/AndroidRuntime(10699): java.lang.IllegalStateException: 
The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(2131230722, class android.widget.ListView) with Adapter(class android.janime.MyAdapter)]

当我在执行 onResponse 后单击列表中的一项时，应用程序崩溃。“确保适配器的内容不是从后台线程修改的，而只是从 UI 线程修改的。”

4

1 回答 1

1

您需要adapter.notifyDataSetChanged();在收到响应时调用，解析数据并将其添加到 arraylist 您应该通知适配器以便更改数据集！

   public void onCreate(Bundle icicle) {
    super.onCreate(icicle);

    // 1. pass context and data to the custom adapter
    MyAdapter adapter = new MyAdapter(this, generateData());

    //2. setListAdapter
    setListAdapter(adapter);
}

private ArrayList<Item> generateData(){
    ArrayList<Item> items = new ArrayList<Item>();
    items.add(new Item("Item 1","First Item on the list"));


    RequestQueue queue = Volley.newRequestQueue(this);
    String url = "http://echo.jsontest.com/just/test/values/two";

    JsonObjectRequest jsObjRequest = new JsonObjectRequest(Method.GET, url, null, new Response.Listener<JSONObject>() {

        @Override
        public void onResponse(JSONObject response) {
           //my loop here
             items.add(new Item("Item 1","this is just a sample "));
adapter.notifyDataSetChanged();
           }
 }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            // TODO Auto-generated method stub

        }
    });

    queue.add(jsObjRequest);

    return items;
于 2013-11-13T05:15:01.473 回答