我正在制作一个应用程序，其中需要在页脚视图中添加进度对话框，但是我无法在页脚视图中获取任何进度对话框：
主要活动：
我想在这个类中的页脚中添加进度对话框
public class MainActivity extends Activity implements OnScrollListener {
// All variables
XmlParser parser;
Document doc;
String xml;
ListView lv;
ListViewAdapter adapter;
ArrayList<HashMap<String, String>> menuItems;
ProgressDialog pDialog;
private String URL = "http://api.androidhive.info/list_paging/?page=1";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_ID = "id";
static final String KEY_NAME = "name";
ProgressDialog dialog;
// Flag for current page
int current_page = 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lv = (ListView) findViewById(R.id.list);
menuItems = new ArrayList<HashMap<String, String>>();
parser = new XmlParser();
xml = parser.getXmlFromUrl(URL); // getting XML
doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
// looping through all item nodes <item>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_ID, parser.getValue(e, KEY_ID)); // id not using any where
map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
// adding HashList to ArrayList
menuItems.add(map);
}
// LoadMore button
dialog=new ProgressDialog(this);
// Button btnLoadMore = new Button(this);
//btnLoadMore.setText("Load More");
// Adding Load More button to lisview at bottom
// lv.addFooterView(dialog);
// I want to use Progress Dialog in footer
/* lv.addFooterView(dialog);*/
// Getting adapter
adapter = new ListViewAdapter(this, menuItems);
lv.setAdapter(adapter);
lv.setOnScrollListener(this);
lv.addFooterView(dialog.getListView());
/**
* Listening to Load More button click event
* */
if(dialog.isShowing())
{
}
/* btnLoadMore.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
// Starting a new async task
new loadMoreListView().execute();
}
});*/
/**
* Listening to listview single row selected
* **/
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name))
.getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
Test123.class);
in.putExtra(KEY_NAME, name);
startActivity(in);
}
});
}
/**
* Async Task that send a request to url
* Gets new list view data
* Appends to list view
* */
private class loadMoreListView extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
// Showing progress dialog before sending http request
if(dialog.isShowing())
{
dialog.cancel();
}
else
{
pDialog = new ProgressDialog(
MainActivity.this);
pDialog.setMessage("Please wait..");
pDialog.setIndeterminate(true);
pDialog.setCancelable(false);
pDialog.show();
}
}
protected Void doInBackground(Void... unused) {
runOnUiThread(new Runnable() {
public void run() {
// increment current page
current_page += 1;
// Next page request
URL = "http://api.androidhive.info/list_paging/?page=" + current_page;
xml = parser.getXmlFromUrl(URL); // getting XML
doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
// looping through all item nodes <item>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_ID, parser.getValue(e, KEY_ID));
map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
// adding HashList to ArrayList
menuItems.add(map);
}
// get listview current position - used to maintain scroll position
int currentPosition = lv.getFirstVisiblePosition();
// Appending new data to menuItems ArrayList
adapter = new ListViewAdapter(
MainActivity.this,
menuItems);
lv.setAdapter(adapter);
// Setting new scroll position
lv.setSelectionFromTop(currentPosition + 1, 0);
}
});
return (null);
}
protected void onPostExecute(Void unused) {
// closing progress dialog
pDialog.dismiss();
}
}
public void onScroll(AbsListView arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
dialog.show();
lv.setOnScrollListener(this);
lv.addFooterView(dialog.getListView());
new loadMoreListView().execute();
}
public void onScrollStateChanged(AbsListView arg0, int arg1) {
// TODO Auto-generated method stub
new loadMoreListView().execute();
}
}
适配器：
public class ListViewAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<HashMap<String, String>> data;
private static LayoutInflater inflater=null;
public ListViewAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
activity = a;
data=d;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
return data.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
if(convertView==null)
vi = inflater.inflate(R.layout.list_item, null);
TextView name = (TextView)vi.findViewById(R.id.name);
HashMap<String, String> item = new HashMap<String, String>();
item = data.get(position);
//Setting all values in listview
name.setText(item.get("name"));
return vi;
}
}
Xml解析器
public class XmlParser {
// constructor
public XmlParser() {
}
public String getXmlFromUrl(String url) {
String xml = null;
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
xml = EntityUtils.toString(httpEntity);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// return XML
return xml;
}
/**
* Getting XML DOM element
* @param XML string
* */
public Document getDomElement(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) {
Log.e("Error: ", e.getMessage());
return null;
} catch (SAXException e) {
Log.e("Error: ", e.getMessage());
return null;
} catch (IOException e) {
Log.e("Error: ", e.getMessage());
return null;
}
return doc;
}
/** Getting node value
* @param elem element
*/
public final String getElementValue( Node elem ) {
Node child;
if( elem != null){
if (elem.hasChildNodes()){
for( child = elem.getFirstChild(); child != null; child = child.getNextSibling() ){
if( child.getNodeType() == Node.TEXT_NODE ){
return child.getNodeValue();
}
}
}
}
return "";
}
/**
* Getting node value
* @param Element node
* @param key string
* */
public String getValue(Element item, String str) {
NodeList n = item.getElementsByTagName(str);
return this.getElementValue(n.item(0));
}
}
任何帮助将不胜感激。