请帮助我：
使用Android 2.2时，此代码非常有效:(直接在标记为注释的行中调用getJSONFromUrl）。
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
int lastInScreen = firstVisibleItem + visibleItemCount;
if (onStatupBool == true) {
JSONParser jParser = new JSONParser();
// JSONObject json = jParser
// .getJSONFromUrl(urlTruyenMoiNhat);
// RetreiveListStory(json);
currentURL = urlTruyenMoiNhat;
GetJsonAsync gjas = new GetJsonAsync();
gjas.execute();
loadMoreOnStartUp = true;
onStatupBool = false;
} else if (lastInScreen == totalItemCount
&& onStatupBool == false
&& loadAnotherCategory == false
&& onStopLoadMore == false) {
// flag = false;
JSONParser jParser = new JSONParser();
String url = "";
if (loadMoreOnStartUp) {
index++;
url = urlTruyenMoiNhat + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyenmoinhat))) {
index++;
url = urlTruyenMoiNhat + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoivova))) {
index++;
url = urlTruyenVova + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if ((categoryStory.equals(getResources()
.getString(R.string.truyencuoi18)))) {
index++;
url = urlTruyen18 + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if ((categoryStory.equals(getResources()
.getString(R.string.truyencuoitinhyeu)))) {
index++;
url = urlTruyenTinhYeu + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoidangian))) {
index++;
url = urlTruyenDanGian + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoitayduky))) {
index++;
url = urlTruyenTayDuKy + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyentieulam))) {
index++;
url = urlTruyenTayDuKy + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyentrangquynh))) {
index++;
url = urlTruyenTrangQuynh + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoigiadinh))) {
index++;
url = urlTruyenCuoiGiaDinh + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyenthocacuoi))) {
index++;
url = urlThoCaCuoi + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoithegioi))) {
index++;
url = urlTruyenCuoiTheGioi + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoingan))) {
index++;
url = urlTruyenNgan + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoitamquoc))) {
index++;
url = urlTruyenCuoiTamQuoc + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoihocsinh))) {
index++;
url = urlTruyenCuoiHocSinh + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoicongso))) {
index++;
url = urlTruyenCuoiCongSo + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoiyhoc))) {
index++;
url = urlTruyenYHoc + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoigiaothong))) {
index++;
url = urlTruyenCuoiGiaoThong + "&&pageIndex="
+ index + "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoisayxin))) {
index++;
url = urlTruyenSayXin + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoithethao))) {
index++;
url = urlTruyenCuoiTheThao + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoiphapluat))) {
index++;
url = urlTruyenCuoiPhapLuat + "&&pageIndex="
+ index + "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoinhahang))) {
index++;
url = urlTruyenCuoiNhaHang + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoinhabinh))) {
index++;
url = urlTruyenCuoiNhaBinh + "&&pageIndex=" + index
+ "&&pageSize=10";
} else if (categoryStory.equals(getResources()
.getString(R.string.truyencuoitongiao))) {
index++;
url = urlTruyenCuoiTonGiao + "&&pageIndex=" + index
+ "&&pageSize=10";
}
// JSONObject json = jParser.getJSONFromUrl(url);
// RetreiveListStory(json);
currentURL = url;
GetJsonAsync gjas = new GetJsonAsync();
gjas.execute();
listLoadMore.setSelection(lastInScreen - 2);
}
loadAnotherCategory = false;
}
});
但是在3.2。不允许直接调用getJSONFromUrl。所以我使用Asyntask： 正如我在上面的代码块中使用的那样。然后它无法正常工作。
private class GetJsonAsync extends AsyncTask<String, Void, JSONObject> {
@Override
protected JSONObject doInBackground(String... params) {
JSONParser jParser = new JSONParser();
JSONObject json = jParser.getJSONFromUrl(currentURL);
RetreiveListStory(json);
return null;
}
@Override
protected void onPostExecute(JSONObject json) {
}
}
RetreiveListStory函数：
private void RetreiveListStory(JSONObject json) {
try {
// Getting Array of Contacts
contacts = json.getJSONArray(RESPONSE);
if (contacts.length() == 0) {
onStopLoadMore = true;
}
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String name = "";
String content = "";
String url = "";
try {
name = new String(c.getString(NAME).getBytes("ISO-8859-1"),
"UTF-8");
content = new String(c.getString(CONTENT).getBytes(
"ISO-8859-1"), "UTF-8");
url = new String(c.getString(URL).getBytes("ISO-8859-1"),
"UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
String decodedName = Html.fromHtml(name).toString();
String decodedContent = Html.fromHtml(content).toString();
listproduct.add(new Product(decodedName, decodedContent, url));
populateListView();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
populateListView（）
private void populateListView() {
ArrayAdapter<Product> adapter = new MyListAdapter();
ListView list = (ListView) findViewById(R.id.listItemView);
list.setAdapter(adapter);
}
更新
何时启动我的应用程序“onStatupBool == true”是真的。然后它调用GetJsonAsync。但之后UI不会更新。因此“lastInScreen == totalItemCount”为true，并在更新URL后继续调用GetJsonAsync。
我不知道为什么它在第一次调用后没有更新UI。