我刚开始使用android并且无法弄清楚如何在片段中获取http json响应。在我的活动中，我很容易使用回调函数，但在Fragment中似乎很难完成相同的操作。
任何帮助都会非常感激。
//SaleFragment.java
public class SaleFragment extends Fragment{
public static final String ARG_CLIENT_NUMBER = "client_number";
private ListView salesListView;
private View rootView;
public SaleFragment() {
// Empty constructor required for fragment subclasses
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_sale, container, false);
int i = getArguments().getInt(ARG_CLIENT_NUMBER);
try{
SaleStackJSON sale_json = new SaleStackJSON();
sale_json.execute("http://test.url/getJson"); //url to retrieve json
// do processing on the result (I do not know how to retrieve them here after the request)
}catch(Exception e){
// resultView.setText(e.getMessage());
}
return rootView;
}
我的JSON类如下：
// SaleStackJSON.java
public class SaleStackJSON extends AsyncTask<String, Void, String>{
InputStream is = null;
String result = "";
JSONArray jArray = null;
String error_text="";
JSONObject j = null;
TextView resultView;
@Override
protected String doInBackground(String... urls) {
// Download JSON data from URL
try {
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(urls[0]);
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
setResult(sb.toString());
// this.jArray = new JSONArray(result);
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
return getResult();
}
public String getResult() {
return result;
}
public void setResult(String result) {
this.result = result;
}
}
编辑1：我使用以下代码填充我的前端。 （显示结果）
JSONArray jArray;
ArrayList all_sales = new ArrayList();
try {
jArray = new JSONArray(result);
int total_retail_outlets = jArray.length();
//LinearLayout scrollable_sale_layout = (LinearLayout)findViewById(R.id.scrollable_sale_layout);
for (int i = 0; i < total_retail_outlets; i++) {
JSONObject jObj = jArray.getJSONObject(i);
String customer_name = jObj.getString("name");
String created_at = jObj.getString("created_at");
String quantity = jObj.getString("quantity");
String billing_amount = jObj.getString("billing_amount");
String discount_percentage = jObj.getString("discount_percentage");
String discount = jObj.getString("discount");
String total = jObj.getString("total");
SalesItem salesData = new SalesItem();
salesData.setBilling_amount(billing_amount);
salesData.setCreated_at(created_at);
salesData.setCustomer_name(customer_name);
salesData.setDiscount(discount);
salesData.setDiscount_percentage(discount_percentage);
salesData.setQuantity(quantity);
salesData.setTotal(total);
all_sales.add(salesData);
}
salesListView.setAdapter(new CustomSaleListAdapter(getActivity(), all_sales));
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
答案 0 :(得分：1)
首先，最好在doInBackground方法中处理您的响应，因为它会使UI线程不那么繁忙，所以：
public class SaleStackJSON extends AsyncTask<String, Void, ArrayList<SalesItem>>
并在doInBackground中执行以下操作：
@Override
protected String doInBackground(String... urls) {
// Download JSON data from URL
try {
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(urls[0]);
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
// this.jArray = new JSONArray(result);
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
ArrayList<SalesItem> all_sales = new ArrayList<SalesItem>();
JSONArray jArray;
try {
jArray = new JSONArray(sb.toString());
int total_retail_outlets = jArray.length();
for (int i = 0; i < total_retail_outlets; i++) {
JSONObject jObj = jArray.getJSONObject(i);
String customer_name = jObj.getString("name");
String created_at = jObj.getString("created_at");
String quantity = jObj.getString("quantity");
String billing_amount = jObj.getString("billing_amount");
String discount_percentage = jObj.getString("discount_percentage");
String discount = jObj.getString("discount");
String total = jObj.getString("total");
SalesItem salesData = new SalesItem();
salesData.setBilling_amount(billing_amount);
salesData.setCreated_at(created_at);
salesData.setCustomer_name(customer_name);
salesData.setDiscount(discount);
salesData.setDiscount_percentage(discount_percentage);
salesData.setQuantity(quantity);
salesData.setTotal(total);
all_sales.add(salesData);
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return all_sales;
}
现在让我们进行最后的改变：
protected void onPostExecute( ArrayList<SalesItem> result) {
salesListView.setAdapter(new CustomSaleListAdapter(getActivity(), result[0]));
}
答案 1 :(得分：0)
This will might help u I do also got the same problem but resolved at the end
protected void onPostExecute(JSONObject result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
if (null != pd && pd.isShowing()) {
pd.dismiss();
}
String message="";
try
{
message=result.getString("message");
}catch(Exception e)
{
e.printStackTrace();
}
try {
if(result!=null&&message.equalsIgnoreCase("Invalid User"))
{
activity.startActivity(new Intent(activity,LoginRegisterOptionScreen.class));
activity.finish();
}
else
{
if(fragment!=null)
{
if(fragment.getClass().getSimpleName().equalsIgnoreCase("ProfileFragment"))
{
((ProfileFragment) fragment).getServerResponse(result);
}
else if (fragment.getClass().getSimpleName().equalsIgnoreCase("reviewScreen")) {
((ReviewScreen) fragment).getServerResponse(result);
}
else if (fragment.getClass().getSimpleName().equalsIgnoreCase("ReviewEditable")) {
((ReviewEditable) fragment).getServerResponse(result);
}
// else if(fragment.getClass().getSimpleName().equalsIgnoreCase("FavoritesFragment"))
// {
// ((FavoritesFragment) fragment).getServerResponse(result);
// }
}
else if (activity != null) {
if (activity.getClass().getSimpleName().equalsIgnoreCase("RegisterScreen2")) {
((RegisterScreen2) activity).getServerResponse(result);
}
else if (activity.getClass().getSimpleName().equalsIgnoreCase("LoginScreen")) {
((LoginScreen) activity).getServerResponse(result);
}
else if (activity.getClass().getSimpleName().equalsIgnoreCase("changePassword")) {
((changePassword) activity).getServerResponse(result);
}
// else if (activity.getClass().getSimpleName().equalsIgnoreCase("googlemap")) {
// ((googlemap) activity).getServerResponse(result);
// }
// else if (activity.getClass().getSimpleName().equalsIgnoreCase("chatter")) {
// try {
// ((chatter) activity).getServerResponse(result);
// } catch (JSONException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
// }
// else if (activity.getClass().getSimpleName().equalsIgnoreCase("Chatlist")) {
// ((Chatlist) activity).getServerResponse(result);
// }
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}