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本文实例讲述了Android利用Intent实现数据传递的方法。分享给大家供大家参考,具体如下:
在Android开发过程中,很多人都熟悉Intent,这是个用于在多个View之间共享数据的类。本节主要讲述通过点选ListView中的文本,把文本中的URL加载到一个新的页面上,并且打印出来。为了方便,我先把前面一篇《Android开发之利用jsoup解析HTML页面的方法》的代码重新贴一下,因为在上一节后,代码做了少许修改:
try {doc = Jsoup.parse(new URL("http://www.51yam.com"), 5000);} catch (MalformedURLException e1) {e1.printStackTrace();} catch (IOException e1) {e1.printStackTrace();}final List<Map<String, String>> list = new ArrayList<Map<String, String>>();Elements es = doc.getElementsByClass("subnav");for (int i=0;i<es.size();i++) {Element e = es.get(i);int count = e.getElementsByTag("a").size();for(int j=0;j<count;j++){Map<String, String> map = new HashMap<String, String>();Element ex = e.getElementsByTag("a").get(j);map.put("title", ex.text());map.put("href", "http://www.51yam.com/"+ex.attr("href"));list.add(map);}}ListView listView = (ListView) findViewById(R.id.listView1);listView.setAdapter(new SimpleAdapter(this, list, android.R.layout.simple_list_item_2,new String[] { "title","href" }, new int[] {android.R.id.text1,android.R.id.text2}));
实现的效果如下:

然后我们需要做的就是当点击ListView中的项目的时候,程序会将每个话题下面的URL链接发送到新的页面显示:
下面是当点击ListView项目的时候,利用Intent传递数据的方法:
listView.setOnItemClickListener(new OnItemClickListener(){@Overridepublic void onItemClick(AdapterView<?> parent, View v, int position,long id) {//Toast.makeText(getApplicationContext(), (TextView), duration)System.out.println("position:"+position);System.out.println("id:"+id);//Toast.makeText(_GetWebResoureActivity.this, list.get(position).get("href"), Toast.LENGTH_SHORT).show();Intent intent = new Intent(v.getContext(),topicdetails.class);intent.putExtra("src", list.get(position).get("href"));startActivityForResult(intent,0);}});
在子页面“topicdetails.java”中,我们可以通过如下的方式来接收传递过来的值:
package com.android.web;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.widget.EditText;import java.lang.Object;public class topicdetails extends Activity {private EditText editText;@Overrideprotected void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.topiccontent);editText = (EditText)this.findViewById(R.id.editText);String srcUrl = getIntent().getStringExtra("src");editText.setText(srcUrl);}}
当然,一定不要忘记了在AndroidManifest.xml文件中添加Activity映射(黄色背景部分):
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"package="com.android.web"android:versionCode="1"android:versionName="1.0" ><uses-sdk android:minSdkVersion="7" /><!-- 加入访问网络的权限 --><uses-permission android:name="android.permission.INTERNET" /><applicationandroid:icon="@drawable/ic_launcher"android:label="@string/app_name" ><activityandroid:label="@string/app_name"android:name="._GetWebResoureActivity" ><intent-filter ><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity><activity android:name=".topicdetails"></activity></application></manifest>
这样当一切工作准备完毕后,运行程序,点击ListView 的Item,我们成功地跳转到了子页面:

以下是所有的源码:
主页面源码:
package com.android.web;import java.io.BufferedInputStream;import java.io.IOException;import java.io.InputStream;import java.net.MalformedURLException;import java.net.URL;import java.net.URLConnection;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.lang.Object;import org.apache.http.util.ByteArrayBuffer;import org.apache.http.util.EncodingUtils;import org.jsoup.Jsoup;import org.jsoup.nodes.Document;import org.jsoup.nodes.Element;import org.jsoup.select.Elements;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.ListView;import android.widget.SimpleAdapter;import android.widget.Toast;public class _GetWebResoureActivity extends Activity {Document doc;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);findViewById(R.id.button1).setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {load();}});}protected void load() {try {doc = Jsoup.parse(new URL("http://www.51yam.com"), 5000);} catch (MalformedURLException e1) {e1.printStackTrace();} catch (IOException e1) {e1.printStackTrace();}final List<Map<String, String>> list = new ArrayList<Map<String, String>>();Elements es = doc.getElementsByClass("subnav");for (int i=0;i<es.size();i++) {Element e = es.get(i);int count = e.getElementsByTag("a").size();for(int j=0;j<count;j++){Map<String, String> map = new HashMap<String, String>();Element ex = e.getElementsByTag("a").get(j);map.put("title", ex.text());map.put("href", "http://www.51yam.com/"+ex.attr("href"));list.add(map);}}ListView listView = (ListView) findViewById(R.id.listView1);listView.setAdapter(new SimpleAdapter(this, list, android.R.layout.simple_list_item_2,new String[] { "title","href" }, new int[] {android.R.id.text1,android.R.id.text2}));listView.setOnItemClickListener(new OnItemClickListener(){@Overridepublic void onItemClick(AdapterView<?> parent, View v, int position,long id) {//Toast.makeText(getApplicationContext(), (TextView), duration)System.out.println("position:"+position);System.out.println("id:"+id);//Toast.makeText(_GetWebResoureActivity.this, list.get(position).get("href"), Toast.LENGTH_SHORT).show();Intent intent = new Intent(v.getContext(),topicdetails.class);intent.putExtra("src", list.get(position).get("href"));startActivityForResult(intent,0);}});}/** * @param urlString * @return */public String getHtmlString(String urlString) {try {URL url = null;url = new URL(urlString);URLConnection ucon = null;ucon = url.openConnection();InputStream instr = null;instr = ucon.getInputStream();BufferedInputStream bis = new BufferedInputStream(instr);ByteArrayBuffer baf = new ByteArrayBuffer(500);int current = 0;while ((current = bis.read()) != -1) {baf.append((byte) current);}return EncodingUtils.getString(baf.toByteArray(), "gbk");} catch (Exception e) {return "";}}}
子页面源码:
package com.android.web;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.widget.EditText;import java.lang.Object;public class topicdetails extends Activity {private EditText editText;@Overrideprotected void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.topiccontent);editText = (EditText)this.findViewById(R.id.editText);String srcUrl = getIntent().getStringExtra("src");editText.setText(srcUrl);}}
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