本文實(shí)例為大家分享了Android新聞瀏覽客戶端，基于php后臺(tái)，供大家參考，具體內(nèi)容如下
1、使用HBuilder進(jìn)行PHP環(huán)境配置，測(cè)試是否可以查詢MySQL語(yǔ)句，之前都已經(jīng)詳細(xì)說(shuō)明過(guò)了。
2、此處php后臺(tái)實(shí)現(xiàn)mysql的查詢功能，并以JSON數(shù)據(jù)格式返回個(gè)客戶端
在PHP此處建立一個(gè)mysql_connect.php文件，實(shí)現(xiàn)數(shù)據(jù)庫(kù)的連接，并設(shè)置字符集格式。
<?php
$con = mysql_connect("localhost","root","123456");
//設(shè)置字符集為UTF-8 可解決中文亂碼
mysql_query("SET NAMES 'utf8'");
mysql_query("SET CHARACTER SET utf8");
mysql_query("SET CHARACTER_SET_RESULT=utf8");
if(!$con){
die(mysql_error());
}
mysql_select_db("newsdemo",$con);
?>
然后新建一個(gè)getNewsJSON.php文件用于進(jìn)行將查詢結(jié)果轉(zhuǎn)換成JSON字符串格式。只需要 json_encode這個(gè)方法即可。
<?php
/*獲得JSON數(shù)據(jù)
* 返回值：title desc time content_url pic_url*/
require 'mysql_connect.php';
$n = 0;
$result = mysql_query("select * from news");
while($row = mysql_fetch_array($result)){
$arr[$n++] = array(
"title"=>$row['title'],
"desc"=>$row['desc'],
"time"=>$row['time'],
"content_url"=>$row['content_url'],
"pic_url"=>$row['pic_url']
);
}
//數(shù)組轉(zhuǎn)化為JSON字符串
echo json_encode($arr);
?>
重點(diǎn)在于Android端的設(shè)計(jì)開(kāi)發(fā)
1、設(shè)計(jì)界面
由于需要以在ListView的每個(gè)Item中設(shè)置相同的格式，所以此處運(yùn)用ListView+Adapter的形式
在主界面LinearLayout中添加一個(gè)ListView控件
2、Mainactivity程序如下：
public class MainActivity extends Activity implements OnItemClickListener{
private ListView lvNews ;
private NewsAdapter adapter ;
//定義集合
private List<News> newsList ;
//獲取json字符串的URL地址
public static final String GET_NEWS_URL = "http://211.87.234.20/NewsDemo/getNewsJSON.php";
//獲取msg之后如何處理
private Handler getNewsHandler = new Handler(){
public void handleMessage(android.os.Message msg){
String jsonData = (String) msg.obj ;
System.out.println(jsonData) ;
try {
JSONArray jsonArray = new JSONArray(jsonData) ;
for(int i=0;i<jsonArray.length();i++){
JSONObject object = jsonArray.getJSONObject(i) ;
String title = object.getString("title") ;
String desc = object.getString("desc") ;
String time = object.getString("time") ;
String content_url = object.getString("content_url") ;
String pic_url = object.getString("pic_url") ;
System.out.println("title="+title) ;
//add一個(gè)News類型的Object
newsList.add(new News(title,desc,time,content_url,pic_url)) ;
}
//通知更新
adapter.notifyDataSetChanged() ;
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} ;
} ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState) ;
setContentView(R.layout.activity_main) ;
lvNews = (ListView) findViewById(R.id.lvNews) ;
//初始化
newsList = new ArrayList<News>();
adapter = new NewsAdapter(this,newsList) ;
lvNews.setAdapter(adapter) ;
lvNews.setOnItemClickListener(this) ;
HttpUtils.getNewsJSON(GET_NEWS_URL,getNewsHandler) ;
}
@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;
}
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {
// TODO Auto-generated method stub
News news = newsList.get(position) ;
Intent intent = new Intent(this,BrowseNewsActivity.class) ;
intent.putExtra("content_url",news.getContent_url()) ;
startActivity(intent) ;
}
}
此處需要一個(gè)工具類HttpUtils以及自定義的NewsAdapter以實(shí)現(xiàn)item的視圖顯示.
HttpUtils代碼如下：
package com.MR.news.utils;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.Message;
import android.widget.ImageView;
public class HttpUtils {
//工具類直接定義成靜態(tài)方法即可
/*url用于內(nèi)部類中，所以要將其設(shè)定為final類型*/
/*讀取完成需要通知主線程，需要使用handler*/
public static void getNewsJSON(final String url,final Handler handler){
//訪問(wèn)網(wǎng)絡(luò)，時(shí)間長(zhǎng)，開(kāi)啟新線程
new Thread(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
HttpURLConnection conn ;
InputStream is ;
try {
conn = (HttpURLConnection) new URL(url).openConnection() ;
//GET方式獲取
conn.setRequestMethod("GET") ;
//得到輸入流
is=conn.getInputStream() ;
//讀取數(shù)據(jù)用緩沖,里面要傳入一個(gè)reader
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
//一行一行讀取數(shù)據(jù)
String line = "";
//沒(méi)讀完一行進(jìn)行拼接,高效
StringBuilder result = new StringBuilder();
while((line = reader.readLine()) != null){
result.append(line);
}
Message msg = new Message() ;
//msg.obj可以放進(jìn)去任何對(duì)象
msg.obj = result.toString() ;
handler.sendMessage(msg) ;
} catch (Exception e) {
e.printStackTrace();
}
}}).start() ;
}
public static void setPicBitMap(final ImageView ivPic,final String pic_url){
new Thread(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
try {
HttpURLConnection conn = (HttpURLConnection) new URL(pic_url).openConnection() ;
conn.connect() ;
InputStream is = conn.getInputStream() ;
//bitmap就是所需圖片資源
/*從資源文件中的到圖片*/
Bitmap bitmap = BitmapFactory.decodeStream(is) ;
ivPic.setImageBitmap(bitmap) ;
is.close() ;
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start() ;
}
}
NewsAdapter代碼如下：
package com.MR.news.adapter;
import java.util.List;
import com.MR.news.R;
import com.MR.news.model.News;
import com.MR.news.utils.HttpUtils;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class NewsAdapter extends BaseAdapter {
//聲明上下文對(duì)象，后面的getView方法需要
private Context context;
private List<News> newsList;
public NewsAdapter(Context context, List<News> newsList){
this.context = context ;
this.newsList = newsList ;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return newsList.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return newsList.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup arg2) {
// TODO Auto-generated method stub
if(convertView == null){
convertView = LayoutInflater.from(context).inflate(R.layout.news_item,null) ;
}
TextView tvTitle = (TextView) convertView.findViewById(R.id.tvTitle) ;
TextView tvDesc = (TextView) convertView.findViewById(R.id.tvDesc) ;
TextView tvTime = (TextView) convertView.findViewById(R.id.tvTime) ;
ImageView ivPic = (ImageView) convertView.findViewById(R.id.ivPic);
News news = newsList.get(position) ;
tvTitle.setText(news.getTitle()) ;
tvDesc.setText(news.getDesc()) ;
tvTime.setText(news.getTime()) ;
String pic_url = news.getPic_url() ;
HttpUtils.setPicBitMap(ivPic, pic_url) ;
return convertView;
}
}
news_item用來(lái)設(shè)置每個(gè)item的顯示格式
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="@+id/ivPic"
android:layout_width="42dp"
android:layout_height="42dp"
android:src="@drawable/ic_launcher"
/>
<TextView
android:id="@+id/tvTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toRightOf="@+id/ivPic"
android:text="title"
android:textSize="18sp" />
<TextView
android:id="@+id/tvDesc"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/tvTitle"
android:layout_below="@+id/tvTitle"
android:text="desc"
android:textSize="18sp" />
<TextView
android:id="@+id/tvTime"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="time"
android:textSize="10sp"
/>
</RelativeLayout>
注意：此item中需要顯示單個(gè)圖片，所以用到Bitmap這個(gè)類。由于用到網(wǎng)絡(luò)傳輸，所以需要用到線程這個(gè)概念??！
關(guān)鍵理解handler message以及l(fā)oop這三者的關(guān)系。
以上就是本文的全部?jī)?nèi)容，希望對(duì)大家學(xué)習(xí)Android軟件編程有所幫助。