不确定它有多清晰，但我遇到的问题是我的适配器多次从 TreeMap 添加相同的位置。这不应该发生/它多次添加同一部电影。
我查看了代码并尝试遵循代码的循环，但我似乎找不到问题。
我已经对我的代码进行了 Gists，因为它太长了，我不想让页面成为垃圾邮件。
如果你们真的想要这一切，我会更新我的问题。
我的应用程序向 API 发出请求并获取电影 ID、标题、信息、海报等的 TreeMap。这个特殊问题出在我的 ListViewAdaptor 上。
ListView 适配器
package com.example.zdroa.fetchmovies;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import java.util.TreeMap;
class ListViewAdaptor extends BaseAdapter {
private Context mContext;
private TreeMap<Integer, String> urls;
private TreeMap<Integer, String> titles;
ListViewAdaptor(Context context, TreeMap<Integer, String> URLS, TreeMap<Integer, String> TITLES) {
mContext = context;
urls = URLS;
titles = TITLES;
}
@Override
public int getCount() {
return urls.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = View.inflate(mContext, R.layout.results_layout, null);
}
ImageView imageView = (ImageView) convertView.findViewById(R.id.ivPosters);
TextView textView = (TextView) convertView.findViewById(R.id.results_layout_tv_movie_name);
Drawable d = mContext.getResources().getDrawable(R.drawable.place_holder_img);
String link_end = urls.ceilingEntry(position).getValue();
String title = titles.ceilingEntry(position).getValue();
Picasso.with(mContext)
.load("http://image.tmdb.org/t/p/w185" + link_end)
.placeholder(d)
.into(imageView);
textView.setText(title);
return convertView;
}
}
MainActivityFragment.java
package com.example.zdroa.fetchmovies;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.TreeMap;
public class MainActivityFragment extends Fragment {
private static String API_KEY = "b692b9da86f1cf0c1b623ea6e2770101";
ListView listView;
Button button;
static TreeMap<Integer, Integer> IDS;
static TreeMap<Integer, String> TITLES;
static TreeMap<Integer, String> POSTERS;
static TreeMap<Integer, String> GENRES;
static TreeMap<Integer, String> PRODUCTION_COUNTRIES;
static TreeMap<Integer, String> OVERVIEW;
static TreeMap<Integer, String> RUNTIME;
public MainActivityFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
listView = (ListView) rootView.findViewById(R.id.lvMovies);
new ImageLoadTask().execute();
//if fragment is visible
if (getActivity() != null) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
System.out.println(TITLES.ceilingEntry(position).getValue());
}
});
}
return rootView;
}
@Override
public void onStart() {
super.onStart();
}
private class ImageLoadTask extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
IDS = new TreeMap<>();
IDS.put(1, 2);
IDS.put(2, 3);
IDS.put(3, 5);
IDS.put(4, 6);
IDS.put(5, 8);
IDS.put(6, 9);
IDS.put(7, 11);
IDS.put(8, 12);
IDS.put(9, 13);
IDS.put(10, 14);
populateTreeMaps();
return null;
}
@Override
protected void onPostExecute(Void result) {
if (getActivity() != null) {
ListViewAdaptor adapter = new ListViewAdaptor(getActivity(), POSTERS, TITLES);
listView.setAdapter(adapter);
System.out.println(POSTERS);
System.out.println(TITLES);
}
}
private Void populateTreeMaps() {
HttpHandler httpHandler = new HttpHandler();
TITLES = new TreeMap<>();
POSTERS = new TreeMap<>();
for (int i = 0; i < IDS.size(); i++) {
String jsonString = httpHandler.makeServiceCall("https://api.themoviedb.org/3/movie/" + IDS.ceilingEntry(i).getValue() + "?api_key=" + API_KEY);
if (jsonString != null) {
try {
//POPULATE ALL THE GRAPHS HERE
getTitles(jsonString, IDS.ceilingEntry(i).getValue());
getPosterURLs(jsonString, IDS.ceilingEntry(i).getValue());
} catch (JSONException e) {
return null;
}
}
}
return null;
}
private void getTitles(String JSONString, Integer mov_id) throws JSONException {
JSONObject jsonObject = new JSONObject(JSONString);
String title = jsonObject.getString("title");
TITLES.put(mov_id, title);
}
private void getPosterURLs(String JSONString, Integer mov_id) throws JSONException {
JSONObject jsonObject = new JSONObject(JSONString);
String url = jsonObject.getString("poster_path");
POSTERS.put(mov_id, url);
}
private void getYoutubeLink() {
}
}
}
最佳答案
您的键->值逻辑有问题。
您使用的 TreeMap 填充了具有间隙 [2,3,5,6, etc] 的键，然后在适配器中您尝试按位置获取项目，显然您的 map 不包含您想要的每个位置的项目，所以你的 ceilingEntry() 返回下一个项目 key >= requested_key
请参阅此说明:https://www.tutorialspoint.com/java/util/treemap_ceilingentry.htm
最简单和最直接的解决方案是移动到 List<Movie>其中 Movie 是一个新的模型类，它包含您需要在适配器中显示的所有数据(url、标题...)。
关于java - 为什么 Adapter 多次向 ListView 添加相同的位置？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/43976318/