我使用ListView后我的notifyDataSetChanged();没有刷新
但我不知道我的代码有什么问题请帮我更新我的数据库更新时的listview。
import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import static android.content.Context.LAYOUT_INFLATER_SERVICE;
public class EventsView extends Fragment {
ListView list4;
String json_string;
String JSON_STRING;
JSONObject JO;
JSONObject jsonObject;
JSONArray jsonArray;
int count = 0;
HashMap<String, Object> obj;
String topic,description,event_date,event_id;
private Context mContext;
private PopupWindow mPopupWindow;
private LinearLayout linearLayout;
private Activity mActivity;
ProgressDialog pDialog;
String finalResult ;
HashMap<String,String> hashMap = new HashMap<>();
HttpParse httpParse = new HttpParse();
String HttpURL = "http://192.168.1.10:8081/sms/update_event.php";
String HttpURLDelete = "http://192.168.1.10:8081/sms/delete_event.php";
SimpleAdapter adapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view= inflater.inflate(R.layout.events_view, container, false);
mContext = getContext();
mActivity = getActivity();
linearLayout = (LinearLayout) view.findViewById(R.id.r2);
list4=(ListView)view.findViewById(R.id.list4);
new show_event().execute();
list4.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
obj = (HashMap<String, Object>) list4.getAdapter().getItem(position);
new show_list().execute();
}
});
return view;
}
class show_event extends AsyncTask<String,String,String> {
ProgressDialog pdLoading = new ProgressDialog(getActivity());
String json_url;
@Override
protected void onPreExecute() {
json_url = "http://192.168.1.10:8081/sms/select_event.php";
pdLoading.setMessage("\tLoading...");
pdLoading.isIndeterminate();
pdLoading.setIndeterminate(true);
pdLoading.setCancelable(false);
pdLoading.show();
}
@Override
protected String doInBackground(String... params) {
try {
URL url = new URL(json_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
while ((JSON_STRING = bufferedReader.readLine()).equals("null")) ;
{
stringBuilder.append(JSON_STRING +"\n");
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return stringBuilder.toString().trim();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result) {
List<Map<String, String>> data2 = null;
data2 = new ArrayList<Map<String, String>>();
json_string = result;
try {
jsonObject = new JSONObject(json_string);
jsonArray = jsonObject.getJSONArray("server_response");
if (jsonArray.length() != 0) {
for (count = 0; count < jsonArray.length(); count++) {
JO = jsonArray.getJSONObject(count);
HashMap<String, String> datanum = new HashMap<String, String>();
datanum.put("A",JO.getString("Id"));
datanum.put("B",JO.getString("Topic"));
datanum.put("C",JO.getString("Description"));
datanum.put("D",JO.getString("Event_Date"));
data2.add(datanum);
}
adapter = new SimpleAdapter(getActivity(),data2, R.layout.listview3, new String[]{"D","B"}, new int[]{R.id.tv1,R.id.tv2});
list4.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
} catch (JSONException e) {
e.printStackTrace();
}
pdLoading.dismiss();
}
}
class show_list extends AsyncTask<String,String,String> {
private int mYear, mMonth, mDay;
ProgressDialog pdLoading = new ProgressDialog(getActivity());
@Override
protected String doInBackground(String... strings) {
event_id=(String)obj.get("A");
topic = (String) obj.get("B");
description=(String)obj.get("C");
event_date=(String)obj.get("D");
return null;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
pdLoading.setMessage("\tLoading...");
pdLoading.isIndeterminate();
pdLoading.setIndeterminate(true);
pdLoading.setCancelable(false);
pdLoading.show();
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
final View customView = inflater.inflate(R.layout.edit_event,null);
mPopupWindow = new PopupWindow(customView, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
mPopupWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
mPopupWindow.setWidth(ViewGroup.LayoutParams.FILL_PARENT);
mPopupWindow.setOutsideTouchable(true);
if(Build.VERSION.SDK_INT>=21){
mPopupWindow.setElevation(5.0f);
}
final EditText edit_topic=(EditText)customView.findViewById(R.id.edit_topic);
final EditText edit_description=(EditText)customView.findViewById(R.id.edit_description);
final EditText edit_date=(EditText)customView.findViewById(R.id.edit_Date);
Button delete_btn=(Button)customView.findViewById(R.id.delete);
Button update_btn=(Button)customView.findViewById(R.id.update);
edit_topic.setText(topic);
edit_description.setText(description);
edit_date.setText(event_date);
final String id=String.valueOf(event_id);
edit_date.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Get Current Date
final Calendar c = Calendar.getInstance();
mYear = c.get(Calendar.YEAR);
mMonth = c.get(Calendar.MONTH);
mDay = c.get(Calendar.DAY_OF_MONTH);
DatePickerDialog datePickerDialog = new DatePickerDialog(getContext(),
new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
edit_date.setText(dayOfMonth + "-" + (monthOfYear + 1) + "-" + year);
}
}, mYear, mMonth, mDay);
datePickerDialog.show();
}
});
update_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String topic= edit_topic.getText().toString();
String description= edit_description.getText().toString();
String edit_event_date=edit_date.getText().toString();
StudentRecordUpdate(id,topic,description,edit_event_date);
mPopupWindow.dismiss();
}
});
delete_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
StudentDelete(id);
}
});
mPopupWindow.showAtLocation(linearLayout, Gravity.CENTER,0,0);
mPopupWindow.setFocusable(true);
mPopupWindow.update();
pdLoading.dismiss();
}
}
public void StudentRecordUpdate(final String id, final String topic, final String description, final String event_date){
class StudentRecordUpdateClass extends AsyncTask<String,Void,String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(getActivity(),"Loading Data",null,true,true);
}
@Override
protected void onPostExecute(String httpResponseMsg) {
super.onPostExecute(httpResponseMsg);
pDialog.dismiss();
Toast.makeText(getActivity(),httpResponseMsg.toString(), Toast.LENGTH_LONG).show();
}
@Override
protected String doInBackground(String... params) {
hashMap.put("Id",params[0]);
hashMap.put("Topic",params[1]);
hashMap.put("Description",params[2]);
hashMap.put("Event_Date",params[3]);
finalResult = httpParse.postRequest(hashMap, HttpURL);
return finalResult;
}
}
StudentRecordUpdateClass studentRecordUpdateClass = new StudentRecordUpdateClass();
studentRecordUpdateClass.execute(id,topic,description,event_date);
}
// Method to Delete Student Record
public void StudentDelete(final String ID) {
class StudentDeleteClass extends AsyncTask<String, Void, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(getActivity(), "Loading Data", null, true, true);
}
@Override
protected void onPostExecute(String httpResponseMsg) {
super.onPostExecute(httpResponseMsg);
pDialog.dismiss();
Toast.makeText(getContext(), httpResponseMsg.toString(), Toast.LENGTH_LONG).show();
getActivity().finish();
}
@Override
protected String doInBackground(String... params) {
// Sending STUDENT id.
hashMap.put("Id", params[0]);
finalResult = httpParse.postRequest(hashMap, HttpURLDelete);
return finalResult;
}
}
StudentDeleteClass studentDeleteClass = new StudentDeleteClass();
studentDeleteClass.execute(ID);
}
}
答案 0 :(得分：0)
初始化adapter时，请尝试使用空列表设置适配器，然后只需将数据添加到列表并在适配器上调用<ProgressBar
android:id="@+id/progressbar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginTop="10dp"
android:max="100"
android:indeterminate="false"
android:progressBackgroundTint="#D3D3D3"
android:progress="50"
android:progressDrawable="@drawable/progressbar"
android:layout_centerVertical="true" />
将列表设为全局
ListView然后在notifyDataSetChanged()中，在List<Map<String, String>> data2 = new ArrayList<Map<String, String>>();
初始化
onCreateView然后在listview的{{1}}中，清除现有列表和新数据，然后只需拨打 list4=(ListView)view.findViewById(R.id.list4);
adapter = new SimpleAdapter(getActivity(),data2, R.layout.listview3, new String[]{"D","B"}, new int[]{R.id.tv1,R.id.tv2});
list4.setAdapter(adapter);
，就像在
onPostExecute答案 1 :(得分：0)
public class EventsView extends Fragment {
ListView list4;
String json_string;
String JSON_STRING;
JSONObject JO;
JSONObject jsonObject;
JSONArray jsonArray;
int count = 0;
HashMap<String, Object> obj;
String topic,description,event_date,event_id;
private Context mContext;
private PopupWindow mPopupWindow;
private LinearLayout linearLayout;
private Activity mActivity;
ProgressDialog pDialog;
String finalResult ;
HashMap<String,String> hashMap = new HashMap<>();
HttpParse httpParse = new HttpParse();
String HttpURL = "http://192.168.1.10:8081/sms/update_event.php";
String HttpURLDelete = "http://192.168.1.10:8081/sms/delete_event.php";
SimpleAdapter adapter;
List<Map<String, String>> data2 = new ArrayList<Map<String, String>>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view= inflater.inflate(R.layout.events_view, container, false);
list4=(ListView)view.findViewById(R.id.list4);
adapter = new SimpleAdapter(getActivity(),data2, R.layout.listview3, new String[]{"D","B"}, new int[]{R.id.tv1,R.id.tv2});
list4.setAdapter(adapter);
mContext = getContext();
mActivity = getActivity();
linearLayout = (LinearLayout) view.findViewById(R.id.r2);
new show_event().execute();
list4.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
obj = (HashMap<String, Object>) list4.getAdapter().getItem(position);
new show_list().execute();
}
});
return view;
}
class show_event extends AsyncTask<String,String,String> {
ProgressDialog pdLoading = new ProgressDialog(getActivity());
String json_url;
@Override
protected void onPreExecute() {
json_url = "http://192.168.1.10:8081/sms/select_event.php";
pdLoading.setMessage("\tLoading...");
pdLoading.isIndeterminate();
pdLoading.setIndeterminate(true);
pdLoading.setCancelable(false);
pdLoading.show();
}
@Override
protected String doInBackground(String... params) {
try {
URL url = new URL(json_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
while ((JSON_STRING = bufferedReader.readLine()).equals("null")) ;
{
stringBuilder.append(JSON_STRING + "\n");
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return stringBuilder.toString().trim();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result) {
data2.clear(); //< --add this
json_string = result;
try {
jsonObject = new JSONObject(json_string);
jsonArray = jsonObject.getJSONArray("server_response");
if (jsonArray.length() != 0) {
for (count = 0; count < jsonArray.length(); count++) {
JO = jsonArray.getJSONObject(count);
HashMap<String, String> datanum = new HashMap<String, String>();
datanum.put("A", JO.getString("Id"));
datanum.put("B", JO.getString("Topic"));
datanum.put("C", JO.getString("Description"));
datanum.put("D", JO.getString("Event_Date"));
data2.add(datanum);
}
adapter.notifyDataSetChanged();//< --- call this
}
} catch (JSONException e) {
e.printStackTrace();
}
pdLoading.dismiss();
}
}
class show_list extends AsyncTask<String,String,String> {
private int mYear, mMonth, mDay;
ProgressDialog pdLoading = new ProgressDialog(getActivity());
@Override
protected String doInBackground(String... strings) {
event_id=(String)obj.get("A");
topic = (String) obj.get("B");
description=(String)obj.get("C");
event_date=(String)obj.get("D");
return null;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
pdLoading.setMessage("\tLoading...");
pdLoading.isIndeterminate();
pdLoading.setIndeterminate(true);
pdLoading.setCancelable(false);
pdLoading.show();
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
final View customView = inflater.inflate(R.layout.edit_event,null);
mPopupWindow = new PopupWindow(customView, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
mPopupWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
mPopupWindow.setWidth(ViewGroup.LayoutParams.FILL_PARENT);
mPopupWindow.setOutsideTouchable(true);
if(Build.VERSION.SDK_INT>=21){
mPopupWindow.setElevation(5.0f);
}
final EditText edit_topic=(EditText)customView.findViewById(R.id.edit_topic);
final EditText edit_description=(EditText)customView.findViewById(R.id.edit_description);
final EditText edit_date=(EditText)customView.findViewById(R.id.edit_Date);
Button delete_btn=(Button)customView.findViewById(R.id.delete);
Button update_btn=(Button)customView.findViewById(R.id.update);
edit_topic.setText(topic);
edit_description.setText(description);
edit_date.setText(event_date);
final String id=String.valueOf(event_id);
edit_date.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Get Current Date
final Calendar c = Calendar.getInstance();
mYear = c.get(Calendar.YEAR);
mMonth = c.get(Calendar.MONTH);
mDay = c.get(Calendar.DAY_OF_MONTH);
DatePickerDialog datePickerDialog = new DatePickerDialog(getContext(),
new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
edit_date.setText(dayOfMonth + "-" + (monthOfYear + 1) + "-" + year);
}
}, mYear, mMonth, mDay);
datePickerDialog.show();
}
});
update_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String topic= edit_topic.getText().toString();
String description= edit_description.getText().toString();
String edit_event_date=edit_date.getText().toString();
StudentRecordUpdate(id,topic,description,edit_event_date);
mPopupWindow.dismiss();
}
});
delete_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
StudentDelete(id);
}
});
mPopupWindow.showAtLocation(linearLayout, Gravity.CENTER,0,0);
mPopupWindow.setFocusable(true);
mPopupWindow.update();
pdLoading.dismiss();
}
}
public void StudentRecordUpdate(final String id, final String topic, final String description, final String event_date){
class StudentRecordUpdateClass extends AsyncTask<String,Void,String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(getActivity(),"Loading Data",null,true,true);
}
@Override
protected void onPostExecute(String httpResponseMsg) {
super.onPostExecute(httpResponseMsg);
pDialog.dismiss();
Toast.makeText(getActivity(),httpResponseMsg.toString(), Toast.LENGTH_LONG).show();
}
@Override
protected String doInBackground(String... params) {
hashMap.put("Id",params[0]);
hashMap.put("Topic",params[1]);
hashMap.put("Description",params[2]);
hashMap.put("Event_Date",params[3]);
finalResult = httpParse.postRequest(hashMap, HttpURL);
return finalResult;
}
}
StudentRecordUpdateClass studentRecordUpdateClass = new StudentRecordUpdateClass();
studentRecordUpdateClass.execute(id,topic,description,event_date);
}
// Method to Delete Student Record
public void StudentDelete(final String ID) {
class StudentDeleteClass extends AsyncTask<String, Void, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(getActivity(), "Loading Data", null, true, true);
}
@Override
protected void onPostExecute(String httpResponseMsg) {
super.onPostExecute(httpResponseMsg);
pDialog.dismiss();
Toast.makeText(getContext(), httpResponseMsg.toString(), Toast.LENGTH_LONG).show();
getActivity().finish();
}
@Override
protected String doInBackground(String... params) {
// Sending STUDENT id.
hashMap.put("Id", params[0]);
finalResult = httpParse.postRequest(hashMap, HttpURLDelete);
return finalResult;
}
}
StudentDeleteClass studentDeleteClass = new StudentDeleteClass();
studentDeleteClass.execute(ID);
}
}