我有一个名为 用户管理 的片段，我从服务器收集数据并将其显示在ListView中。它也可以通过SwipeRefreshLayout刷新。
如果我获得1-4个用户的数据，它会正确显示数据。但是，如果我获得超过4个用户的数据，它会正确地显示前4个，而不是第五个，它是第一个，而不是第6个，它是第二个，依此类推等等。
我已经尝试了所有我能想到的东西，适配器正确地获取数据，ListView正确地获得了适配器，但由于某种原因，它显示了4个用户的峰值，并在之后简单地重复它们（有趣的是事情是，如果我添加一个用户然后刷新，它只是在列表中再次重复下一个用户，所以它肯定知道用户号的变化）
你能帮我找到问题吗？
java类：
package com.softwarenation.jetfuel.fragments.userManagement;
import android.app.AlertDialog;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.ListFragment;
import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.widget.SwipeRefreshLayout;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.android.volley.VolleyError;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshListView;
import com.softwarenation.jetfuel.R;
import com.softwarenation.jetfuel.activities.MainActivity;
import com.softwarenation.jetfuel.fragments.Stations;
import com.softwarenation.jetfuel.managers.JetfuelManager;
import com.softwarenation.jetfuel.managers.StatusManager;
import com.softwarenation.jetfuel.managers.UserManager;
import com.softwarenation.jetfuel.utility.Global;
import com.softwarenation.jetfuel.utility.GlobalConnection;
import com.softwarenation.jetfuel.utility.users.User_pictures;
import com.softwarenation.jetfuel.utility.users.Users_mana;
import org.nicktate.projectile.Method;
import org.nicktate.projectile.Projectile;
import org.nicktate.projectile.StringListener;
import java.io.InputStream;
import java.util.ArrayList;
public class UserManagement extends Fragment {
private SwipeRefreshLayout swipeRefreshLayout;
//private View refreshView;
private Global font = new Global();
private ListView listView;
private ArrayList<User_pictures> pictureses = new ArrayList<User_pictures>();
private static boolean isfirst = false;
private PullToRefreshListView pullToRefreshView;
/**---------------------------------------------------------------------------------------------*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
/**---------------------------------------------------------------------------------------------*/
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_usermanagemnet, container, false);
listView = (ListView)rootView.findViewById(R.id.list);
swipeRefreshLayout = (SwipeRefreshLayout)rootView.findViewById(R.id.swipe);
// refreshView = (View) rootView.findViewById(R.id.swipe);
//First time, we get the data from a server, then only display that data until the user calls for a refresh
if(!StatusManager.getInstance().getUsermStatus()){
UsersTask usersTask = new UsersTask();
usersTask.execute();
}else{
setContent();
}
Button addUser = (Button)rootView.findViewById(R.id.addUser_button);
addUser.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Fragment fragment = new AddUser();
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
}
});
// Set a listener to be invoked when the list should be refreshed.
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
Log.e("start","onRefresh");
new GetDataTask().execute();
}
}
);
/* pullToRefreshView = (PullToRefreshListView)rootView.findViewById(R.id.pull_to_refresh_listview);
pullToRefreshView.bringToFront();
pullToRefreshView.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener<ListView>() {
@Override
public void onRefresh(PullToRefreshBase<ListView> refreshView) {
// Do work to refresh the list here.
new GetDataTask().execute();
}
});*/
return rootView;
}
public void setOnRefreshListener (SwipeRefreshLayout.OnRefreshListener listener){
swipeRefreshLayout.setOnRefreshListener(listener);
}
public boolean isRefreshing(){
return swipeRefreshLayout.isRefreshing();
}
public void setRefreshing(boolean refreshing){
swipeRefreshLayout.setRefreshing(refreshing);
}
public SwipeRefreshLayout getSwipeRefreshLayout(){
return swipeRefreshLayout;
}
//on refresh, get new data from the server
private class GetDataTask extends AsyncTask<Void, Void, String[]> {
@Override
protected String[] doInBackground(Void... voids) {Log.e("start","GetDataTask");
UsersTask usersTask = new UsersTask();
usersTask.execute();
return new String[0];
}
@Override
protected void onPostExecute(String[] result) {
// Call onRefreshComplete when the list has been refreshed.
// pullToRefreshView.onRefreshComplete();
super.onPostExecute(result);
MainActivity.setBackDisabled(false);
Log.e("GetDataTask","completed");
}
}
private class SampleItem {
public String id;
public String title;
public String username;
public String groupName;
public int userPicture;
public int editPicture;
public int dPicture;
public String activated;
public SampleItem(String id, String title, String username, String groupName, int userPicture, int editPicture, int dPicture, String activated ) {
this.id = id;
this.title = title;
this.username = username;
this.groupName = groupName;
this.userPicture = userPicture;
this.editPicture = editPicture;
this.dPicture = dPicture;
this.activated = activated;
}
}
static class ViewHolder {
private String checkBox;
private RelativeLayout relativeLayout;
private LinearLayout linearLayout;
private RelativeLayout relativeLayout2;
public void setCheckBox(String checkBox) {
this.checkBox = checkBox;
}
public void setLinearLayout(LinearLayout linearLayout) {
this.linearLayout = linearLayout;
}
public void setRelativeLayout(RelativeLayout relativeLayout) {
this.relativeLayout = relativeLayout;
}
public void setRelativeLayout2(RelativeLayout relativeLayout2) {
this.relativeLayout2 = relativeLayout2;
}
public LinearLayout getLinearLayout() {
return linearLayout;
}
public RelativeLayout getRelativeLayout() {
return relativeLayout;
}
public RelativeLayout getRelativeLayout2() {
return relativeLayout2;
}
public RelativeLayout getCheckBox() {
return relativeLayout;
}
}
public class SampleAdapter extends ArrayAdapter<SampleItem> {
final ViewHolder holder = new ViewHolder();
public SampleAdapter(Context context) {
super(context, 0);
}
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.row_usermana, null);
ImageView userPicture = (ImageView)convertView.findViewById(R.id.userpicture);
userPicture.setImageDrawable(getResources().getDrawable(getItem(position).userPicture));
TextView title = (TextView)convertView.findViewById(R.id.user_name);
font.setFont(title, 3, getActivity());
title.setText(getItem(position).title);
TextView username = (TextView)convertView.findViewById(R.id.username);
font.setFont(username, 2, getActivity());
username.setText(getItem(position).username);
TextView groupname = (TextView)convertView.findViewById(R.id.groupName);
font.setFont(groupname, 2, getActivity());
groupname.setText(getItem(position).groupName);
ImageView useredit = (ImageView)convertView.findViewById(R.id.editbutton);
useredit.setImageDrawable(getResources().getDrawable(getItem(position).editPicture));
useredit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Bundle bundle = new Bundle();
bundle.putString("user_id", getItem(position).id);
Fragment fragment = new EditProfile();
fragment.setArguments(bundle);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
}
});
/**---------------*/
ImageView userdelate = (ImageView)convertView.findViewById(R.id.deletebutton);
userdelate.setImageDrawable(getResources().getDrawable(getItem(position).dPicture));
holder.setLinearLayout((LinearLayout)convertView.findViewById(R.id.lin_show_profile));
//LinearLayout show = (LinearLayout)convertView.findViewById(R.id.lin_show_profile);
holder.getLinearLayout().setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Bundle bundle = new Bundle();
bundle.putString("user_id", getItem(position).id);
Fragment fragment = new ShowProfile();
fragment.setArguments(bundle);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
}
});
//
holder.setRelativeLayout((RelativeLayout)convertView.findViewById(R.id.delate_user));
//RelativeLayout delete_user = (RelativeLayout)convertView.findViewById(R.id.delate_user);
holder.getRelativeLayout().setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
DialogStop("Are you sure?", getItem(position).username, getActivity(), getItem(position).id);
}
});
//
//holder.setCheckBox(getItem(position).activated);
//
/**---------------*/
//Red or Blue background
// RelativeLayout settings = (RelativeLayout)convertView.findViewById(R.id.settingsbutton);
holder.setRelativeLayout2((RelativeLayout) convertView.findViewById(R.id.settingsbutton));
//if(getItem(position).activated.equals("false")) {
if (getItem(position).activated.equals("false")) {
holder.getLinearLayout().setBackground(getResources().getDrawable(R.drawable.discrepancy_background_red));
holder.getRelativeLayout().setBackground(getResources().getDrawable(R.drawable.discrepancy_background_red));
holder.getRelativeLayout2().setBackground(getResources().getDrawable(R.drawable.discrepancy_background_red));
}
//holder.setCheckBox(getItem(position).activated);
convertView.setTag(holder);
} else {
convertView.getTag();
}
return convertView;
}
}
public void DialogStop(String title, String message,Context context, final String id){
new AlertDialog.Builder(context)
.setTitle(title)
.setMessage(message)
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//dialog.cancel();
DeleteTask deleteTask = new DeleteTask();
deleteTask.execute(id);
}
})
.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
})
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
private class DeleteTask extends AsyncTask<String, String, String>{
@Override
protected String doInBackground(String... params) {
String response = null;
try {
response = new GlobalConnection().DELETE( getString(R.string.apicdeleteuser) + params[0].toString() );
Log.v("response", response + "");
} catch (Exception e) {
e.printStackTrace();
}
return response;
}
@Override
protected void onPostExecute(String response) {
Log.v("response", response + "");
}
}
private class UsersTask extends AsyncTask<String, Void, ArrayList<Users_mana>> {
@Override
protected ArrayList<Users_mana> doInBackground(String... strings) {
//Users_mana users = null;
String response = null;
ArrayList<Users_mana> users_manas = null;
try{Log.e("start","GET via GlobalConnection()");
response = new GlobalConnection().GET( getString(R.string.apiusers));
users_manas = new Gson().fromJson(response, new TypeToken<ArrayList<Users_mana>>(){}.getType());
Log.e("start","setUsers_mana");
UserManager.getInstance().setUsers_mana(users_manas);
}catch (Exception e){
Log.e("response error", e.getMessage().toString());
}
return users_manas;
}
@Override
protected void onPostExecute(ArrayList<Users_mana> response) {
if(!response.isEmpty()) {Log.e("start","setContent()");
setContent();
StatusManager.getInstance().setUsermStatus(true);
Log.e("UsermStatus:",String.valueOf(StatusManager.getInstance().getUsermStatus()));
}
super.onPostExecute(response);
}
}
private void setContent(){
SampleAdapter adapter = new SampleAdapter(getActivity());
adapter.notifyDataSetChanged();
try {
if (!UserManager.getInstance().getUsers_mana().isEmpty()) {
for (int i = 0; i < UserManager.getInstance().getUsers_mana().size(); i++) {
Log.e("adding to adapter:",UserManager.getInstance().getUsers_mana().get(i).firstName + " " + UserManager.getInstance().getUsers_mana().get(i).lastName + "" + UserManager.getInstance().getUsers_mana().get(i).id + "" + UserManager.getInstance().getUsers_mana().get(i).username + "group:" + UserManager.getInstance().getUsers_mana().get(i).group);
adapter.add(new SampleItem(
UserManager.getInstance().getUsers_mana().get(i).id
, UserManager.getInstance().getUsers_mana().get(i).firstName + " " + UserManager.getInstance().getUsers_mana().get(i).lastName
, UserManager.getInstance().getUsers_mana().get(i).username
, UserManager.getInstance().getUsers_mana().get(i).group
, R.drawable.users_test
, R.drawable.settings
, R.drawable.delete
, UserManager.getInstance().getUsers_mana().get(i).activated
));
}
listView.setAdapter(adapter);Log.e("setting","ListView");
}
}catch (Exception e){
Log.e("error setContent", e.getMessage().toString());
}
}
/*
private class PicturesTask extends AsyncTask<String, String ,String>{
@Override
protected String doInBackground(String... urls) {
//String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
for(int i = 0; i < urls.length; i++) {
if(UserManager.getInstance().getUsers_mana().get(i).photo != null) {
InputStream in = new java.net.URL(getString(R.string.jetfuel_url ) + UserManager.getInstance().getUsers_mana().get(i).username).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
pictureses.add(new User_pictures(mIcon11, UserManager.getInstance().getUsers_mana().get(i).username, UserManager.getInstance().getUsers_mana().get(i).id));
UserManager.getInstance().setUserPictureses(pictureses);
}
}
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String s) {
if(!UserManager.getInstance().getUserPictureses().isEmpty()) {
for (int i = 0; i < UserManager.getInstance().getUserPictureses().size(); i++) {
Log.v("pictures", UserManager.getInstance().getUserPictureses().get(i).picture + "");
}
}
super.onPostExecute(s);
}
}
*/
/**---------------------------------------------------------------------------------------------*/
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.main, menu);
//menu.removeItem(R.id.Station);
super.onCreateOptionsMenu(menu, inflater);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.Station:
Fragment fragment = new Stations();
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/**---------------------------------------------------------------------------------------------*/
}
xml视图：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/blue">
<Button
android:id="@+id/addUser_button"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:text="@string/add_user"
android:background="@drawable/button_yellow_background"
android:textStyle="bold"
android:textSize="20sp"
android:textColor="@color/blue"/>
<android.support.v4.widget.SwipeRefreshLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/swipe">
<ListView
android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@color/blue"
/>
</android.support.v4.widget.SwipeRefreshLayout>
</LinearLayout>
</RelativeLayout>
谢谢！
答案 0 :(得分：1)
您的SampleAdapter.getView()方法存在严重问题。
当您向下滚动时，屏幕顶部消失的View将重新用于注入底部。重复使用的View是convertView getView参数。
在您编写代码时，重复使用的视图将注入完全相同的数据（因为滚动时if (convertView == null) {始终为false）。
图片和文字未更新。
当你向下滚动时，顶部消失的元素只显示在底部，其他人也是如此......
你应该做的事情如下：
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.row_usermana, null);
// The ViewHolder constructor should handle the mapping of its views
holder = new ViewHolder(convertView);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
// Here you should only use holder as in:
holder.userpicture.setImageDrawable(getResources().getDrawable(getItem(position).userPicture));
...
}
答案 1 :(得分：0)
这种方法看起来很奇怪，也许是可疑的。我没有在这个示例代码中的任何地方看到getUsers_mana（），所以我不知道是不是问题。首先，你应该调用'UserManager.getInstance（）。getUsers_mana（）'，然后每次调用'get（i）'并将结果存储在变量中。
private void setContent(){
SampleAdapter adapter = new SampleAdapter(getActivity());
adapter.notifyDataSetChanged();
try {
if (!UserManager.getInstance().getUsers_mana().isEmpty()) {
for (int i = 0; i < UserManager.getInstance().getUsers_mana().size(); i++) {
Log.e("adding to adapter:",UserManager.getInstance().getUsers_mana().get(i).firstName + " " + UserManager.getInstance().getUsers_mana().get(i).lastName + "" + UserManager.getInstance().getUsers_mana().get(i).id + "" + UserManager.getInstance().getUsers_mana().get(i).username + "group:" + UserManager.getInstance().getUsers_mana().get(i).group);
adapter.add(new SampleItem(
UserManager.getInstance().getUsers_mana().get(i).id
, UserManager.getInstance().getUsers_mana().get(i).firstName + " " + UserManager.getInstance().getUsers_mana().get(i).lastName
, UserManager.getInstance().getUsers_mana().get(i).username
, UserManager.getInstance().getUsers_mana().get(i).group
, R.drawable.users_test
, R.drawable.settings
, R.drawable.delete
, UserManager.getInstance().getUsers_mana().get(i).activated
));
}
listView.setAdapter(adapter);Log.e("setting","ListView");
}
}catch (Exception e){
Log.e("error setContent", e.getMessage().toString());
}
}
答案 2 :(得分：0)
这是因为你没有在
中做任何事情else {
convertView.getTag();
}
点击这里
Why we should re-assign values for a recycled convertView in getView()
您必须使用第5行，第6行等的数据将值重新分配给convertView，否则它仍包含旧数据
答案 3 :(得分：0)
删除顶部的holder的初始化，只需将这行代码放在getView函数的开头。
ViewHolder holder = null;
如果持有者为null，则需要重新初始化持有者，如果非null，则需要使用最新数据更新持有者。
答案 4 :(得分：0)
请参阅此示例，它可能会对您有所帮助