Comprehensive usage of HttpClient, Xmlpullparser, ListView and Baseadapter

Summary of Knowledge points

1, through the Android API built-in class httpclient from the background to extract data, httpclient is an interface, so with his subclass to instantiate Defaulthttpclient, the specific code is as follows:

Private List<news> getnewsfrominternet () {

HttpClient client = null;

try {

Define a client

Client = new Defaulthttpclient ();

Defining the Get method

HttpGet get = new HttpGet ("Http://10.0.2.2:8080/NetEaseServer/new.xml");

Execute request

HttpResponse response = Client.execute (get);

int statusCode = Response.getstatusline (). Getstatuscode ();

if (StatusCode = = 200) {

InputStream is = Response.getentity (). getcontent ();

list<news> newinfolist = Getnewlistfrominputstream (IS);

return newinfolist;

} else {

LOG.I (TAG, "Access failed:" + statusCode);

}

} catch (Exception e) {

E.printstacktrace ();

} finally {

if (client! = NULL) {

Client.getconnectionmanager (). Shutdown (); Close and release resources

}

}

return null;

}

3,xmlpullparser parsing from the later sent over the XML file

Private list<news> Getnewlistfrominputstream (InputStream is) throws Exception {

Xmlpullparser parser = Xml.newpullparser (); Create a Pull Parser

Parser.setinput (IS, "utf-8"); Specifies the parsing stream, and the encoding

int eventtype = Parser.geteventtype ();

List<news> newinfolist = null;

News newinfo = null;

while (eventtype! = xmlpullparser.end_document) {//If not at the end, continue looping

String tagName = Parser.getname (); Node name

Switch (eventtype) {

Case Xmlpullparser.start_tag://<news>

if ("News". Equals (TagName)) {

Newinfolist = new arraylist<news> ();

} else if ("new". Equals (TagName)) {

Newinfo = new News ();

} else if ("title". Equals (TagName)) {

Newinfo.settitle (Parser.nexttext ());

} else if ("detail". Equals (TagName)) {

Newinfo.setdetail (Parser.nexttext ());

} else if ("comment". Equals (TagName)) {

Newinfo.setcomment (Parser.nexttext ());

} else if ("image". Equals (TagName)) {

Newinfo.setbitmap (Parser.nexttext ());

}

Break

Case Xmlpullparser.end_tag://</news>

if ("New". Equals (TagName)) {

Newinfolist.add (Newinfo);

}

Break

Default

Break

}

EventType = Parser.next (); Remove an event type

}

return newinfolist;

}

3, bound to the ListView This control needs to set the properties of the Setadapter, belong to the first to define a class to implement Baseadapter, mainly to implement the baseadapter of the two methods, the specific code is as follows:

Class Myadapter extends baseadapter{

@Override

public int GetCount () {

TODO auto-generated Method Stub

return Listnewsinfo.size ();

}

@Override

Public Object getItem (int position) {

TODO auto-generated Method Stub

return null;

}

@Override

public long getitemid (int position) {

TODO auto-generated Method Stub

return 0;

}

@Override

Public View GetView (int position, View Convertview, ViewGroup parent) {

View view = null;

if (Convertview = = null) {

Layoutinflater inflater = Getlayoutinflater ();

View = Inflater.inflate (R.layout.activity_item, NULL);

} else {

view = Convertview;

}

Re-assignment does not result in the retention of the original data in the cached object

Smartimageview Sivicon = (smartimageview) View.findviewbyid (R.id.iv_itemimg_icon);

TextView Tvtitle = (TextView) View.findviewbyid (r.id.tv_item_tvtitle);

TextView Tvdetail = (TextView) View.findviewbyid (R.id.tv_item_discuss);

TextView tvcomment = (TextView) View.findviewbyid (r.id.tv_item_content);

News newinfo = listnewsinfo.get (position);

Sivicon.setimageurl (Newinfo.getbitmap ()); Set up a picture

Tvtitle.settext (Newinfo.gettitle ());

Tvdetail.settext (Newinfo.getdetail ());

Tvcomment.settext (newinfo.getcomment () + "thread");

return view;

}

}

General usage of HttpClient, Xmlpullparser, ListView, and Baseadapter