问题描述
我有一个列表视图，它通过 Json 从 sqlite 数据库中获取数据.
I have a listview which is fetching data from sqlite database by Json.
我想把它变成动态列表视图，在滚动结束时，加载更多项目"出现在列表的页脚，同时加载更多项目并将它们添加到适配器(例如每次 10 个项目).我在实现此功能时遇到问题.请帮我解决.谢谢.
I want to turn it into dynamic listview that at the end of scroll, a "load more items" appears in the footer of the list while loading more items and adding them to the adapter (for example 10 items each time). I have problem in implementing this feature. Please help me with it. Thanks.
public class AllProductsActivity extends Activity {
... defining variables...;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new LoadAllProducts().execute();
}
class LoadAllProducts extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
... progress dialog...
}
protected String doInBackground(String... args) {
countryList = new ArrayList<Country>();
List<NameValuePair> params = new ArrayList<NameValuePair>();
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
String description = c.getString(TAG_DESCRIPTION);
String due_date = c.getString(TAG_DUE_DATE);
String staff = c.getString(TAG_STAFF);
String status = c.getString(TAG_STATUS);
country = new Country(id,name,description,
due_date, staff, status);
countryList.add(country);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
pDialog.dismiss();
runOnUiThread(new Runnable() {
public void run() {
displayListView();
}
});
}
}
private void displayListView() {
dataAdapter = new MyCustomAdapter(this,
R.layout.country_info, countryList);
ListView listView = (ListView) findViewById(R.id.listView1);
listView.setAdapter(dataAdapter);
}
private class MyCustomAdapter extends ArrayAdapter<Country> {
... blah blah blah ...
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
Log.v("ConvertView", String.valueOf(position));
if (convertView == null) {
... blah blah blah ...
}
return convertView;
}
}
}
推荐答案
你试试下面的代码
list.setOnScrollListener(new OnScrollListener() {
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
if(firstVisibleItem+visibleItemCount == totalItemCount && totalItemCount!=0)
{
if(flag_loading == false)
{
flag_loading = true;
additems();
}
}
}
});
在additem() 中添加接下来的10 项到数组列表并将flag_loading 设置为false.并调用 notifydatasetchanged.它应该可以工作.
in the additem() add the next 10 items to array list and set the flag_loading as false. and call notifydatasetchanged. it should work.
这篇关于动态列表视图添加“加载更多项目"在滚动的末尾的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！