Question

我的json输出：

[{"FirstName":"childname2"},{"FirstName":"childname4"}]

我试图用json数据填充我的listview，这是我用post方法得到的，通过这样做，我在postexecute中得到了我的总json [{"FirstName":"childname2"},{"FirstName":"childname4"}]输出。当我试图通过使用for循环传递列表中的这个值它没有显示任何错误,,,以及没有填充我的列表，，建议,,,,

我的java：

private ListView lv=(ListView) findViewById(R.id.listView1);
    @Override
    protected void onPostExecute(String result) {
    // TODO Auto-generated method stub
    super.onPostExecute(result);
    Toast.makeText(Certify_Child_Count.this,result, Toast.LENGTH_LONG).show();
    if (result.equals("[]")) 
    {
        Toast.makeText(Certify_Child_Count.this,
                "Wrong Username or Password", Toast.LENGTH_LONG).show();

    }
    else 
    {
        Toast.makeText(Certify_Child_Count.this,result, Toast.LENGTH_LONG).show();
        JSONArray arr=new JSONArray();
        JSONObject obj = null;
        //ArrayAdapter<String> adapter=new ArrayAdapter<String>(Certify_Child_Count.this, android.R.layout.simple_list_item_1, list);
        //lv.setAdapter(adapter);
        for(int i=0;i<arr.length();i++)
        {
            Toast.makeText(Certify_Child_Count.this,"going into for loop", Toast.LENGTH_LONG).show();

        try {
            obj=arr.getJSONObject(i);
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try { 
            list.add(obj.getString("FirstName"));
            Toast.makeText(Certify_Child_Count.this,obj.getString("FirstName"), Toast.LENGTH_LONG).show();
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        }

    }
    }

Answer 1

您需要使用适配器来填充ListView。

您需要创建一个类来实现ArraryAdapters<> 例如：

public class ListAdapters extends ArraryAdapters<string>

此类实现getView()方法。在这里，您需要填充列表视图。

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    if (convertView == null) {

        LayoutInflater inflater = context.getLayoutInflater();

        convertView = inflater.inflate(R.layout.list_rows, null);

        holder = new ViewHolder();

        holder.tectview = (TextView) convertView
                .findViewById(R.id.questionary_name);
        convertView.setTag(holder);
    }
    holder = (ViewHolder) convertView.getTag();


    String s = items[position];

    holder.tectview.setText(s);
    return convertView;
}

Answer 2

你的适配器在哪里？您需要一个适配器来显示列表的数据。如果是单个文本，您可以使用基本适配器，并在每次完成请求并解析数据时通知它。

Answer 3

你应该改变

JSONArray arr=new JSONArray();

到

JSONArray arr=new JSONArray(result);

您正在创建一个空JSONArray而不添加结果。

Answer 4

你很幸运，我只是完成了与你几乎一样的演示。希望它可以帮助你解决问题。

    package com.ecnu.vendingmachine;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.ListFragment;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.SimpleAdapter;

import com.ecnu.vendingmachine.widgets.JSONParser;

public class VendingFragment extends ListFragment {

    private String Tag = "VendingFragment";
    private static final String TAG_SUCCESS = "success";

    private ListView listView;

    // Progress Dialog
    private ProgressDialog pDialog;
    // Creating JSON Parser object
    JSONParser jsonParser = new JSONParser();
    JSONArray vendingmachine = null;

    ArrayList<HashMap<String, String>> vendinglist;

    // url to get all products list
    MainActivity main = new MainActivity();
    private String url_all_vendingmachine = main.getIP()
            + "vendingmachine/get_all_vendingmachine.php";

    // products JSONArray

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        return inflater.inflate(R.layout.vending_main, container, false);
    }

     @Override 
     public void onViewCreated (View view, Bundle savedInstanceState) {

        vendinglist = new ArrayList<HashMap<String, String>>();
        //listView = (ListView) view.findViewById(R.id.list);

        listView = getListView();
        new get_all_vendingmachine().execute();
    }   

    class get_all_vendingmachine extends AsyncTask<String, String, String> {

        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(getActivity());
            pDialog.setMessage("Creating Product..");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
            Log.i(Tag, "pDialog");
        }

        protected String doInBackground(String... args) {

            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();

            Log.i(Tag, url_all_vendingmachine);
            // getting JSON Object
            // Note that create product url accepts POST method

            JSONObject json = jsonParser.makeHttpRequest(
                    url_all_vendingmachine, "GET", params);

            // check log cat for response
            Log.i(Tag, json.toString());

            // check for success tag
            try {
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1) {
                    // Ada record Data (SUCCESS = 1)
                    // Getting Array of vendingmachine
                    vendingmachine = json.getJSONArray("vendings");

                    // looping through All vendingmachine
                    for (int i = 0; i < vendingmachine.length(); i++) {
                        JSONObject c = vendingmachine.getJSONObject(i);

                        // Storing each json item in variable
                        String id = c.getString("VMid");
                        String name = c.getString("Name");
                        String address = c.getString("Address");
                        Log.i(Tag, id);
                        Log.i(Tag, name);
                        Log.i(Tag, address);
                        // creating new HashMap
                        HashMap<String, String> map = new HashMap<String, String>();
                        // adding each child node to HashMap key => value
                        map.put("VMid", id);
                        map.put("Name", name);
                        map.put("Address", address);

                        // adding HashList to ArrayList
                        vendinglist.add(map);
                    }

                } else {
                    // failed to create product
                    getActivity().finish();
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }

        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) {
            // dismiss the dialog once done
            pDialog.dismiss();
            getActivity().runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    // updating listview
                    // HashMap<String, String>中的key
                    String[] from = { "Name", "Address", "VMid" };
                    // list_item.xml中对应的控件ID
                    int[] to = { R.id.vending_name, R.id.vending_address,
                            R.id.vending_id };
                    Log.i(Tag, from[0]);
                    SimpleAdapter adapter = new SimpleAdapter(getActivity(),
                            vendinglist, R.layout.vending_list, from, to);
                    listView.setAdapter(adapter);
                }
            });
        }

    }

}

vending_main_xml：

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/whiteColor" >

    <include
        android:id="@+id/layout_buy_title_actionbar"
        layout="@layout/headbar_title" />

    <ListView
        android:id="@id/android:list"
        android:layout_below="@id/layout_buy_title_actionbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:cacheColorHint="@android:color/transparent"
        android:divider="@drawable/reader_item_divider"
        android:listSelector="@android:color/transparent" >
    </ListView>

</RelativeLayout>

vending_list.xml：

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="@dimen/selectVmListCell_Height"
    android:orientation="vertical" >

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="@dimen/selectVmListCell_Height"
        android:layout_gravity="center_vertical"
        android:background="@drawable/bg_listview"
        android:gravity="center_vertical"
        android:paddingLeft="@dimen/layout_Margin_10" >

        <LinearLayout
            android:id="@+id/imageTypeLayout"
            android:layout_width="@dimen/smallImage_HW_45"
            android:layout_height="fill_parent"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:gravity="center_vertical"
            android:orientation="vertical" >

            <ImageView
                android:id="@+id/vendingImage"
                style="@style/smallImageStyle"
                android:src="@drawable/buy_main_not_shop" />

            <TextView
                android:id="@+id/distanceText"
                style="@style/smallTxtStyle"
                android:layout_gravity="center_horizontal"
                android:gravity="center"
                android:singleLine="true"
                android:textColor="@color/lightOrangeColor" />
        </LinearLayout>

        <RelativeLayout
            android:id="@+id/vendingSave"
            android:layout_width="47.0dip"
            android:layout_height="fill_parent"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true" >

            <ImageView
                android:id="@+id/vendingSaveImage"
                android:layout_width="27.0dip"
                android:layout_height="27.0dip"
                android:layout_centerInParent="true"
                android:layout_centerVertical="true"
                android:background="@drawable/bg_favor_btn" />
        </RelativeLayout>

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_centerVertical="true"
            android:layout_marginLeft="@dimen/layout_Margin_10"
            android:layout_toLeftOf="@id/vendingSave"
            android:layout_toRightOf="@id/imageTypeLayout"
            android:gravity="center_vertical"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/vending_name"
                style="@style/midDarkGrayTxtStyle"
                android:layout_width="fill_parent" />

            <TextView
                android:id="@+id/vending_address"
                style="@style/smallLightGrayTxtStyle"
                android:layout_width="fill_parent"
                android:maxLines="2" />

            <LinearLayout
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal" >

                <TextView
                    style="@style/smallLightGrayTxtStyle"
                    android:text="Number：" />

                <TextView
                    android:id="@+id/vending_id"
                    style="@style/smallLightGrayTxtStyle" />
            </LinearLayout>
        </LinearLayout>
    </RelativeLayout>

</LinearLayout>

希望它可以帮助您找到如何将listview放入片段中。我的listview中的元素很复杂，如果你只想要一行，它比我编码的更简单。

在android ListView中填充json

4 个答案: