我从 Internet 找到了一个关于XML和ListView项目的示例，我只在更新的项目中更改了 xml 链接和标签名称。应用程序工作正常，但在主屏幕上是否显示“无数据”
原始项目在这里
编辑的项目是这样的：
主.java
public class Main extends ListActivity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listplaceholder);
ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
String xml = XMLfunctions.getXML();
Document doc = XMLfunctions.XMLfromString(xml);
/*
int numResults = XMLfunctions.numResults(doc);
if((numResults <= 0)){
Toast.makeText(Main.this, "Geen resultaten gevonden", Toast.LENGTH_LONG).show();
finish();
}
*/
NodeList nodes = doc.getElementsByTagName("note");
for (int i = 0; i < nodes.getLength(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element)nodes.item(i);
///////I EDITED THESE TAGS////////////////////
map.put("to",XMLfunctions.getValue(e, "to"));
map.put("from", "From:" + XMLfunctions.getValue(e, "from"));
mylist.add(map);
}
ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.main,
new String[] { "to", "from" },
new int[] { R.id.item_title, R.id.item_subtitle });
setListAdapter(adapter);
final ListView lv = getListView();
lv.setTextFilterEnabled(true);
/*
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
@SuppressWarnings("unchecked")
HashMap<String, String> o = (HashMap<String, String>) lv.getItemAtPosition(position);
Toast.makeText(Main.this, "ID '" + o.get("id") + "' was clicked.", Toast.LENGTH_LONG).show();
}
});
*/
}
}
XMLfunctions.java
public class XMLfunctions {
public final static Document XMLfromString(String xml){
Document doc = null;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = dbf.newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(xml));
doc = db.parse(is);
} catch (ParserConfigurationException e) {
System.out.println("XML parse error: " + e.getMessage());
return null;
} catch (SAXException e) {
System.out.println("Wrong XML file structure: " + e.getMessage());
return null;
} catch (IOException e) {
System.out.println("I/O exeption: " + e.getMessage());
return null;
}
return doc;
}
/** Returns element value
* @param elem element (it is XML tag)
* @return Element value otherwise empty String
*/
public final static String getElementValue( Node elem ) {
Node kid;
if( elem != null){
if (elem.hasChildNodes()){
for( kid = elem.getFirstChild(); kid != null; kid = kid.getNextSibling() ){
if( kid.getNodeType() == Node.TEXT_NODE ){
return kid.getNodeValue();
}
}
}
}
return "";
}
public static String getXML(){
String line = null;
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
///////I EDITED THIS LINK////////////////////
HttpPost httpPost = new HttpPost("http://www.w3schools.com/xml/note.xml");
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
line = EntityUtils.toString(httpEntity);
} catch (UnsupportedEncodingException e) {
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
} catch (MalformedURLException e) {
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
} catch (IOException e) {
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
}
return line;
}
/*
public static int numResults(Document doc){
Node results = doc.getDocumentElement();
int res = -1;
try{
res = Integer.valueOf(results.getAttributes().getNamedItem("count").getNodeValue());
}catch(Exception e ){
res = -1;
}
return res;
}
*/
public static String getValue(Element item, String str) {
NodeList n = item.getElementsByTagName(str);
return XMLfunctions.getElementValue(n.item(0));
}
}
日志猫
03-16 00:53:05.032: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property
03-16 00:53:12.401: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property
03-16 00:53:12.711: E/Trace(1902): error opening trace file: No such file or directory (2)
03-16 00:53:15.351: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property
03-16 00:53:39.282: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property
03-16 00:53:40.640: E/ActivityThread(875): Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d5f200 that was originally bound here
03-16 00:53:40.640: E/ActivityThread(875): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d5f200 that was originally bound here
03-16 00:53:40.640: E/ActivityThread(875): at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
03-16 00:53:40.640: E/ActivityThread(875): at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
03-16 00:53:40.640: E/ActivityThread(875): at android.app.ContextImpl.bindService(ContextImpl.java:1418)
03-16 00:53:40.640: E/ActivityThread(875): at android.app.ContextImpl.bindService(ContextImpl.java:1407)
03-16 00:53:40.640: E/ActivityThread(875): at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
03-16 00:53:40.640: E/ActivityThread(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
03-16 00:53:40.640: E/ActivityThread(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
03-16 00:53:40.640: E/ActivityThread(875): at com.android.emailcommon.service.ServiceProxy.test(ServiceProxy.java:191)
03-16 00:53:40.640: E/ActivityThread(875): at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1850)
03-16 00:53:40.640: E/ActivityThread(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
03-16 00:53:40.640: E/ActivityThread(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
03-16 00:53:40.640: E/ActivityThread(875): at android.os.AsyncTask$2.call(AsyncTask.java:287)
03-16 00:53:40.640: E/ActivityThread(875): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
03-16 00:53:40.640: E/ActivityThread(875): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
03-16 00:53:40.640: E/ActivityThread(875): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
03-16 00:53:40.640: E/ActivityThread(875): at java.lang.Thread.run(Thread.java:856)
03-16 00:53:40.652: E/StrictMode(875): null
03-16 00:53:40.652: E/StrictMode(875): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d5f200 that was originally bound here
03-16 00:53:40.652: E/StrictMode(875): at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
03-16 00:53:40.652: E/StrictMode(875): at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
03-16 00:53:40.652: E/StrictMode(875): at android.app.ContextImpl.bindService(ContextImpl.java:1418)
03-16 00:53:40.652: E/StrictMode(875): at android.app.ContextImpl.bindService(ContextImpl.java:1407)
03-16 00:53:40.652: E/StrictMode(875): at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
03-16 00:53:40.652: E/StrictMode(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
03-16 00:53:40.652: E/StrictMode(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
03-16 00:53:40.652: E/StrictMode(875): at com.android.emailcommon.service.ServiceProxy.test(ServiceProxy.java:191)
03-16 00:53:40.652: E/StrictMode(875): at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1850)
03-16 00:53:40.652: E/StrictMode(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
03-16 00:53:40.652: E/StrictMode(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
03-16 00:53:40.652: E/StrictMode(875): at android.os.AsyncTask$2.call(AsyncTask.java:287)
03-16 00:53:40.652: E/StrictMode(875): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
03-16 00:53:40.652: E/StrictMode(875): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
03-16 00:53:40.652: E/StrictMode(875): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
03-16 00:53:40.652: E/StrictMode(875): at java.lang.Thread.run(Thread.java:856)
03-16 00:53:40.981: E/ActivityThread(875): Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d5f790 that was originally bound here
03-16 00:53:40.981: E/ActivityThread(875): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d5f790 that was originally bound here
03-16 00:53:40.981: E/ActivityThread(875): at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
03-16 00:53:40.981: E/ActivityThread(875): at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
03-16 00:53:40.981: E/ActivityThread(875): at android.app.ContextImpl.bindService(ContextImpl.java:1418)
03-16 00:53:40.981: E/ActivityThread(875): at android.app.ContextImpl.bindService(ContextImpl.java:1407)
03-16 00:53:40.981: E/ActivityThread(875): at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
03-16 00:53:40.981: E/ActivityThread(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
03-16 00:53:40.981: E/ActivityThread(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
03-16 00:53:40.981: E/ActivityThread(875): at com.android.emailcommon.service.AccountServiceProxy.getDeviceId(AccountServiceProxy.java:116)
03-16 00:53:40.981: E/ActivityThread(875): at com.android.exchange.ExchangeService.getDeviceId(ExchangeService.java:1249)
03-16 00:53:40.981: E/ActivityThread(875): at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1856)
03-16 00:53:40.981: E/ActivityThread(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
03-16 00:53:40.981: E/ActivityThread(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
03-16 00:53:40.981: E/ActivityThread(875): at android.os.AsyncTask$2.call(AsyncTask.java:287)
03-16 00:53:40.981: E/ActivityThread(875): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
03-16 00:53:40.981: E/ActivityThread(875): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
03-16 00:53:40.981: E/ActivityThread(875): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
03-16 00:53:40.981: E/ActivityThread(875): at java.lang.Thread.run(Thread.java:856)
03-16 00:53:40.991: E/StrictMode(875): null
03-16 00:53:40.991: E/StrictMode(875): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d5f790 that was originally bound here
03-16 00:53:40.991: E/StrictMode(875): at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
03-16 00:53:40.991: E/StrictMode(875): at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
03-16 00:53:40.991: E/StrictMode(875): at android.app.ContextImpl.bindService(ContextImpl.java:1418)
03-16 00:53:40.991: E/StrictMode(875): at android.app.ContextImpl.bindService(ContextImpl.java:1407)
03-16 00:53:40.991: E/StrictMode(875): at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
03-16 00:53:40.991: E/StrictMode(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
03-16 00:53:40.991: E/StrictMode(875): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
03-16 00:53:40.991: E/StrictMode(875): at com.android.emailcommon.service.AccountServiceProxy.getDeviceId(AccountServiceProxy.java:116)
03-16 00:53:40.991: E/StrictMode(875): at com.android.exchange.ExchangeService.getDeviceId(ExchangeService.java:1249)
03-16 00:53:40.991: E/StrictMode(875): at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1856)
03-16 00:53:40.991: E/StrictMode(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
03-16 00:53:40.991: E/StrictMode(875): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
03-16 00:53:40.991: E/StrictMode(875): at android.os.AsyncTask$2.call(AsyncTask.java:287)
03-16 00:53:40.991: E/StrictMode(875): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
03-16 00:53:40.991: E/StrictMode(875): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
03-16 00:53:40.991: E/StrictMode(875): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
03-16 00:53:40.991: E/StrictMode(875): at java.lang.Thread.run(Thread.java:856)
03-16 00:53:46.391: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property
03-16 00:53:46.651: E/Trace(1958): error opening trace file: No such file or directory (2)
03-16 00:53:49.301: E/SurfaceFlinger(36): ro.sf.lcd_density must be defined as a build property