注意：
首先写任何东西之前。这不是重复，因为如果是，那么为什么我会在这里发布。我没有找到任何类似于stackoverflow的问题。答案对我有帮助，连续两天。
问题：
我有一个活动，它接受两个数据字段，然后转到下一个活动，其中view pager活动，活动打开2个片段posts和profile。这里的问题是，当我回到第一个活动输入不同的数据并转到片段时，listview显示重复的数据。
我尝试了所有可能的解决方案但没有效果。
我试图清除适配器。 我试图传递空适配器。 我在片段的生命周期中尝试了更多的东西，但没有。
所以请我帮忙。提前谢谢。
package psychrating.psychrating;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.Spinner;
import android.widget.Toast;
import java.util.ArrayList;
/**
* Created by Ahmeed on 8/7/2017.
*/
public class PostsFragment extends Fragment {
static ListView posts_list;
Spinner list_order;
SearchView search;
String category, date, activity;
boolean get_data;
public static ArrayList<String> data = null;
static Context c;
transient ViewHolder holder;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
data = null;
activity = getArguments().getString("activity");
category = getArguments().getString("category");
date = getArguments().getString("date");
if (activity == "main") {
// get_data = true;
}else {
// get_data = true;
}
View view = inflater.inflate(R.layout.post_tab, container, false);
init(view);
posts_list.clearChoices();
if (searchResultses != null) {
searchResultses.clear();
searchResultses = null;
}
return view;
}
private void init(View view) {
posts_list = (ListView) view.findViewById(R.id.posts_list);
list_order = (Spinner) view.findViewById(R.id.list_order);
search = (SearchView) view.findViewById(R.id.search);
posts_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
holder = (ViewHolder) view.getTag();
Temp temp = new Temp();
temp.name = holder.name.getText().toString();
temp.highest = holder.highest.getText().toString();
temp.dname = holder.dname.getText().toString();
temp.date = holder.date.getText().toString();
temp.category = holder.category;
temp.sdesc = holder.sdesc;
temp.ddesc = holder.ddesc;
Intent i = new Intent(c, ProfileActivity.class);
i.putExtra("holder", temp);
startActivity(i);
}
});
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
c = context;
}
@Override
public void onResume() {
super.onResume();
searchResultses = new ArrayList<>();
new Server(this.getActivity(), "posts").execute(category, date);
}
public static final String TAG ="ahmed";
static void removeCommas() {
StringBuilder word = new StringBuilder();
for (int i = 0; i < data.size(); i++) {
for (int j = 0; j < data.get(i).length(); j++) {
char c = data.get(i).charAt(j);
if (c != ',') {
word.append(c);
}else {
words.add(word.toString());
word.delete(0, word.length());
}
}
}
}
@Override
public void onPause() {
super.onPause();
searchResultses = null;
adapter = null;
}
@Override
public void onDestroyView() {
super.onDestroyView();
}
static void addToClass() {
SearchResults s;
int offset = 0;
for (int j = 0; j < words.size(); j += 8) {
Log.d(TAG, String.valueOf(words.size()));
s = new SearchResults();
for (int i = 0; i < 8; i++) {
offset = 1;
s.add(words.get(i * offset));
}
offset += 1;
s.init();
searchResultses.add(s);
}
}
static ArrayList<SearchResults> searchResultses = null;
static ArrayList<String> words = new ArrayList<>();
static MyCustomBaseAdapter adapter = null;
public static void fillList() {
removeCommas();
addToClass();
ArrayList<SearchResults> empty = new ArrayList<>();
adapter = new MyCustomBaseAdapter(c, empty);
adapter = new MyCustomBaseAdapter(c, searchResultses);
posts_list.setAdapter(adapter);
}
}
注意：
fillList是一个在完成检索数据时被asynctask调用的函数。使用data变量并从数据中删除逗号并向searchResult类
package psychrating.psychrating;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.io.Serializable;
import java.util.ArrayList;
/**
* Created by Ahmeed on 8/10/2017.
*/
public class MyCustomBaseAdapter extends BaseAdapter {
private static ArrayList<SearchResults> searchArrayList = null;
private LayoutInflater mInflater;
public MyCustomBaseAdapter(Context context, ArrayList<SearchResults> results) {
super();
searchArrayList = results;
mInflater = LayoutInflater.from(context);
}
public int getCount() {
return searchArrayList.size();
}
public Object getItem(int position) {
return searchArrayList.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.row, parent, false);
holder = new ViewHolder(convertView);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.name.setText(searchArrayList.get(position).getName());
holder.highest.setText(searchArrayList.get(position).getHighest());
holder.dname.setText(searchArrayList.get(position).getDName());
holder.date.setText(searchArrayList.get(position).getDate());
holder.category = searchArrayList.get(position).getCategory();
holder.sdesc = searchArrayList.get(position).getSdesc();
holder.ddesc = searchArrayList.get(position).getDdesc();
convertView.setTag(holder);
return convertView;
}
}
服务器类
package psychrating.psychrating;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.support.v7.app.AlertDialog;
import android.util.Log;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
/**
* Created by Ahmeed on 8/6/2017.
*/
public class Server extends AsyncTask<String, String, String> {
private Context context;
private ProgressDialog progressDialog;
private AlertDialog.Builder builder;
private String type;
private static ArrayList<String> data = null;
Server(Context context, String type) {
this.context = context;
this.type = type;
}
private void createPreDialog(String message) {
progressDialog = new ProgressDialog(context);
progressDialog.setMessage(message);
progressDialog.setCancelable(false);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
progressDialog.create();
}
progressDialog.show();
}
@Override
protected void onPreExecute() {
super.onPreExecute();
createPreDialog("hold on");
}
@Override
protected String doInBackground(String... params) {
switch (type) {
case "login":
String personName = params[0];
String personEmail = params[1];
String id = params[2];
//
OutputStreamWriter outputStreamWriter = null;
BufferedWriter writer = null;
BufferedReader bufferedReader = null;
HttpURLConnection connection = null;
String line;
String result = null;
try {
URL url = new URL("http://192.168.1.64/blabla/sign_in.php");
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setConnectTimeout(8000);
outputStreamWriter = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");
writer = new BufferedWriter(outputStreamWriter);
String parameters = "name=" + personName + "&email=" + personEmail + "&id=" + id;
writer.write(parameters);
writer.flush();
if (connection.getResponseCode() == 200) {
bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
while ((line = bufferedReader.readLine()) != null) {
result = line;
}
} else {
result = "Server Error";
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (outputStreamWriter != null) {
outputStreamWriter.close();
}
if (connection != null) {
connection.disconnect();
}
if (bufferedReader != null) {
bufferedReader.close();
}
if (writer != null) {
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
case "posts":
String category = params[0];
String date = params[1];
//
OutputStreamWriter outputStreamWriter1 = null;
BufferedWriter writer1 = null;
BufferedReader bufferedReader1 = null;
HttpURLConnection connection1 = null;
String line1 = "";
String result1 = null;
try {
URL url1 = new URL("http://192.168.1.64/blabla/posts.php");
connection1 = (HttpURLConnection) url1.openConnection();
connection1.setRequestMethod("POST");
connection1.setDoOutput(true);
connection1.setDoInput(true);
connection1.setConnectTimeout(8000);
outputStreamWriter1 = new OutputStreamWriter(connection1.getOutputStream(), "UTF-8");
writer1 = new BufferedWriter(outputStreamWriter1);
String parameters1 = "category="+category+"&date="+date;
writer1.write(parameters1);
writer1.flush();
data = new ArrayList<>();
if (connection1.getResponseCode() == 200) {
bufferedReader1 = new BufferedReader(new InputStreamReader(connection1.getInputStream()));
while ((line1 = bufferedReader1.readLine()) != null) {
data.add(line1);
}
} else {
result1 = "Server Error";
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (outputStreamWriter1 != null) {
outputStreamWriter1.close();
}
if (connection1 != null) {
connection1.disconnect();
}
if (bufferedReader1 != null) {
bufferedReader1.close();
}
if (writer1 != null) {
writer1.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return result1;
}
return null;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
progressDialog.dismiss();
switch (type) {
case "login":
switch (s) {
case "Connect Error":
createDialog(s);
break;
case "Done":
Toast.makeText(context, s, Toast.LENGTH_LONG).show();
MainActivity.updateUI(true);
break;
case "Already Exist":
MainActivity.updateUI(true);
break;
case "Server Error":
createDialog(s);
break;
}
break;
case "posts":
if (data != null) {
PostsFragment.data = data;
PostsFragment.fillList();
data = null;
}
}
}
private void createDialog(String message) {
builder = new AlertDialog.Builder(context);
builder.setTitle("Error");
builder.setMessage(message);
builder.setCancelable(false);
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
builder.create();
builder.show();
}
}
答案 0 :(得分：0)
试试这个。 searchResultses.clear（）;在addToClass（）的开头
static void addToClass() {
SearchResults s;
searchResultses.clear();
int offset = 0;
for (int j = 0; j < words.size(); j += 8) {
Log.d(TAG, String.valueOf(words.size()));
s = new SearchResults();
for (int i = 0; i < 8; i++) {
offset = 1;
s.add(words.get(i * offset));
}
offset += 1;
s.init();
searchResultses.add(s);
}
}
答案 1 :(得分：0)
PostsFragment.java中的words会使元素重复，在removeCommas()方法中首先清除单词，然后从数据中将值添加到words。