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我正在試圖將json數據轉換爲自定義列表視圖。 當我運行應用程序時，它只顯示空白布局文件。在自定義列表視圖中獲取JSON結果android
從http://api.androidhive.info/feed/feed.json
這裏的JSON源爲我做了什麼
this is main activity class
package com.example.jsonexample;
import java.net.URL;
import org.json.JSONObject;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends Activity {
TextView name,email;
handlexml obj;
//String url="http://api.androidhive.info/volley/person_object.json";
//String url="http://api.androidhive.info/feed/feed.json";
ListView lv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//name=(TextView)findViewById(R.id.textView1);
//email=(TextView)findViewById(R.id.textView2);
lv=(ListView)findViewById(R.id.listView1);
lv.setAdapter(new adapterforlist(this));
//open();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/*public void open()
{
obj = new handlexml(url);
obj.fetchJSON();
name.setText(obj.getname());
email.setText(obj.getemail());
}*/
}
這是自定義列表視圖適配器
package com.example.jsonexample;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
public class adapterforlist extends BaseAdapter{
Context context;
TextView tv1,tv2;
handlexml jobj;
String url="http://api.androidhive.info/feed/feed.json";
//String url="http://api.androidhive.info/volley/person_object.json";
public adapterforlist(Context c) {
// TODO Auto-generated constructor stub
this.context=c;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return 0;
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int arg0, View rootview, ViewGroup viewgrp) {
// TODO Auto-generated method stub
LayoutInflater ll = (LayoutInflater)context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
rootview=ll.inflate(R.layout.custom, null, true);
tv1=(TextView)rootview.findViewById(R.id.textView1);
tv2=(TextView)rootview.findViewById(R.id.textView2);
jobj= new handlexml(url);
jobj.fetchJSON();
while(jobj.parsingcomplete)
{
tv1.setText(jobj.getname());
tv2.setText(jobj.getemail());
}
return rootview;
}
}
這是JSON獲取和解析類
package com.example.jsonexample;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class handlexml {
String name;
String email;
String stringurl;
boolean parsingcomplete=true;
public handlexml(String url){
this.stringurl=url;
}
public String getname() {
return name;
}
public String getemail() {
return email;
}
public void readandparseJSON (String in) {
try {
JSONObject reader = new JSONObject(in);
JSONArray feed = reader.getJSONArray("feed");
JSONObject reader1= feed.getJSONObject(feed.length());
for (int i=0; i<=reader1.length();i++)
{
name=reader1.getString("name");
email= reader1.getString("url");
}
parsingcomplete= false;
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void fetchJSON() {
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
try {
URL url=new URL(stringurl);
HttpURLConnection conn= (HttpURLConnection)url.openConnection();
conn.setConnectTimeout(15000);
conn.setReadTimeout(10000);
conn.setRequestMethod("GET");
conn.setDoInput(true);
conn.connect();
InputStream stream = conn.getInputStream();
String data =convertStreamToString(stream);
readandparseJSON(data);
stream.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
thread.start();
}
static String convertStreamToString(java.io.InputStream is) {
java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\\A");
return s.hasNext() ? s.next() : "";
}
}
這是主要的xml文件
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
這是listadapter
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Small Text"
android:textAppearance="?android:attr/textAppearanceSmall" />
</LinearLayout>
我建議你使用Volley庫。 – GVillani82 2014-10-01 21:46:22
您不應該在getView中執行REST調用 - getView只返回列表中的單行。你想首先加載數據，然後解析它，然後你將解析的Java模型（作爲列表）添加到Adapter中，然後在getView（）中充氣列表項視圖，從你的解析列表中獲取位於索引'position'的項，在view中設置數據並從getView方法返回視圖。 – 2014-10-01 22:02:08
@ Damian walczac 我已經嘗試過這種方法與asyncktask但沒有運氣 應用程序現在正在關閉。 – 2014-10-02 12:33:34