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我有以下代码：

package com.example.myfirstapp;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.UnknownHostException;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.TextView;

public class FetchData extends Activity {
    private TextView textView;
    private JSONObject jObject;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fetch_data);
        textView = (TextView) findViewById(R.id.TextView1);

        Intent intent = getIntent();
        String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
        readWebpage(message);
    }

    private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {
            String response = "";
            for (String url : urls) {
                DefaultHttpClient client = new DefaultHttpClient();
                HttpGet httpGet = new HttpGet(url);
                try {
                    HttpResponse execute = client.execute(httpGet);
                    InputStream content = execute.getEntity().getContent();

                    BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
                    String s = "";
                    while ((s = buffer.readLine()) != null) {
                        response += s;
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            return response;
            mParseResponse(response);
        }

        @Override
        protected void onPostExecute(String result) {
            textView.setText(result);
        }
    }

    public void readWebpage(String message) {

        //Intent intent = getIntent();
        //String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

        DownloadWebPageTask task = new DownloadWebPageTask();
        task.execute(new String[] {message});

    }

    ArrayList<String> year, title, details, director, rating, cover;
    // For Parse Login Response From Server
    public void mParseResponse(String response) throws UnknownHostException { 

        year=new ArrayList<String>();
        title=new ArrayList<String>();
        details=new ArrayList<String>();
        director=new ArrayList<String>();
        rating=new ArrayList<String>();
        cover=new ArrayList<String>();

        try {
            JSONObject jObject = new JSONObject(response);
            JSONObject jsonobjresults = jObject.getJSONObject("results");
            JSONArray jsonarrayresult = jsonobjresults.getJSONArray("result");
            for(int i=0;i<jsonarrayresult.length(); i++){
                JSONObject mJsonObj = jsonarrayresult.getJSONObject(i);
                year.add(mJsonObj.getString("year"));
                title.add(mJsonObj.getString("title"));
                details.add(mJsonObj.getString("details"));
                director.add(mJsonObj.getString("director"));
                rating.add(mJsonObj.getString("rating"));
                cover.add(mJsonObj.getString("cover"));
            }
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

我对如何创建自定义适配器感到困惑。是的，我已经完成了教程，但仍然存在混乱。另外，当我调用 mParseResponse 时出现错误。任何想法我哪里出错了，我应该如何实现列表视图？

4

1 回答 1

0

也许这个简单的示例自定义适配器列表视图会用这些东西让你站起来。主要活动

public class MainActivity extends Activity {

    String [] children = {
            "Award 1",
            "Award 2",
            "Award 3",
            "Award 4",
            "Award 5",
            "Award 6",
            "Award 7",
            "Award 8",
            "Award 9",
            "Award 10",
            "Award 11",
            "Award 12",
            "Award 13",
            "Award 14",
            "Award 15"};

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ListView list = (ListView) findViewById(R.id.listview);
        CustomAdapter adapter = new CustomAdapter(this, children);
        list.setAdapter(adapter);
    }

自定义适配器

public class CustomAdapter extends BaseAdapter {
//  you could have instead extend ArrayAdapter if you wished, i find it less fickle but less flexible
//  extends CursorAdapter is available too for listviews backed by cursors
    private LayoutInflater inflator;
    private String[] children;

    public CustomAdapter(Context context, String[] children) {
        super();
//      pass what you need into the constructor. in this case the string array and context.
//      do as much as you can here and not in getView because getView acts for each row
//      --> it will greatly help performance
        this.children = children;
        inflator = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
//      v----  your listview won't show anything if this is left default (at 0).  
        return children.length;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
//      getView is where all the action takes place
//      first inflate the xml that holds the row and somehow connect it to convertView, the parameter
//      checking if null allows these views to be recycled when they go off-screen not just made one per row
//      ---> it will greatly help performance 
        if (convertView == null) {
            convertView = inflator.inflate(R.layout.row, parent, false);
        }
//      then find the individual views with this xml (everything just like onCreate)
        ImageView img = (ImageView) convertView.findViewById(R.id.imageView1);
        TextView tv = (TextView) convertView.findViewById(R.id.textView1);
//      then perform your actions to the your views
//      each textView is set to an element in the array based on position. this is my listview limiter here.
//      each imageview is set to the same picture but you should now have an idea how to set different images (based on position)
//      using listview position in correspondence with array/arraylist positions is a very useful technique.
        img.setImageResource(R.drawable.ic_launcher);
        tv.setText(children[position]);
//      v---- return your view, it's important.
        return convertView;
    }

}

行.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:src="@drawable/ic_launcher" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="TextView" />

</RelativeLayout>

结果 射击

要熟悉 listview，请观看此视频： http ://www.youtube.com/watch?v=wDBM6wVEO70

至于您的其他问题，您将不得不发布 logcat 以获得更好的响应。

于 2012-11-30T12:34:26.153 回答