Android 自定义阵列适配器仅在快速滚动时显示重复项

我的listview工作得差不多很好。当我快速向上或向下滚动时，每次都会显示相同的3-4张图片，慢慢变成右图

用于检索我认为需要修复的位图的代码

public Bitmap retrieveBitmap(String url) throws Exception {
        InputStream inputStream = null;
        try {
            inputStream = this.retrieveStream(url);
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inSampleSize = 8;
            final Bitmap bitmap = BitmapFactory.decodeStream(inputStream, null, options);
            return bitmap;
        } finally {
            try {
                if (inputStream != null) {
                    inputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

在我添加选项示例大小之前，它在我滚动时不断崩溃，我只是从另一个堆栈问题中复制了这个问题，但不确定它除了以某种方式减小大小之外，还做了什么

适配器类

package com.example.jdmb;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MoviesAdapter extends ArrayAdapter<Movies> {
    private ArrayList<Movies> movieData;
    private Activity context;

    public MoviesAdapter(Context context, int resource,
            ArrayList<Movies> objects) {
        super(context, resource, objects);
        this.context = (Activity) context;
        this.movieData = objects;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        ViewHolder holder;
        if (view == null) {
            LayoutInflater vi = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = vi.inflate(R.layout.list_row, parent, false);
            holder = new ViewHolder();
            holder.id = (TextView) view.findViewById(R.id.movieId);
            holder.title = (TextView) view.findViewById(R.id.movieTitle);
            holder.vote_avg = (TextView) view.findViewById(R.id.movieAvg);
            holder.backdrop_path = (ImageView) view
                    .findViewById(R.id.movieBackdrop);
            holder.release_date = (TextView) view
                    .findViewById(R.id.movieRelease);
            holder.original_title = (TextView) view
                    .findViewById(R.id.movieTitle2);
            holder.vote_count = (TextView) view.findViewById(R.id.movieCount);
            holder.adult = (TextView) view.findViewById(R.id.movieAdult);
            holder.poster = (ImageView) view.findViewById(R.id.moviePoster);
            holder.popularity = (TextView) view
                    .findViewById(R.id.moviePopularity);
            view.setTag(holder);

        } else {
            holder = (ViewHolder) view.getTag();

        }
        Movies movie = movieData.get(position);

        if (movie != null) {
            // check to see if each individual textview is null.
            // if not, assign some text!

            holder.id.setText("id: " + movie.getId());
            holder.title.setText("title: " + movie.getTitle());
            holder.vote_avg.setText("vote_avg: " + movie.getVote_average());
            DownloadBitmap.downloadBitmap(holder.backdrop_path,
                    movie.getBackdrop_path());
            holder.release_date.setText("release_date: "
                    + movie.getRelease_date());
            holder.original_title.setText("original_title: "
                    + movie.getOriginal_title());
            holder.vote_count.setText("vote_count: " + movie.getVote_count());
            holder.adult.setText("adult: " + movie.isAdult());
            DownloadBitmap
                    .downloadBitmap(holder.poster, movie.getPoster_path());
            holder.popularity.setText("popularity: " + movie.getPopularity());

        }
        return view;

    }

    private static class ViewHolder {
        TextView id;
        TextView title;
        TextView vote_avg;
        ImageView backdrop_path;
        TextView release_date;
        TextView original_title;
        TextView vote_count;
        TextView adult;
        ImageView poster;
        TextView popularity;
    }
}

package com.example.jdmb；
导入java.util.ArrayList；
导入android.app.Activity；
导入android.content.Context；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.ArrayAdapter；
导入android.widget.ImageView；
导入android.widget.TextView；
公共类MoviesAdapter扩展了ArrayAdapter{
私有ArrayList电影数据；
私人活动语境；
公共MoviesAdapter（上下文、int资源、，
ArrayList对象）{
超级（上下文、资源、对象）；
this.context=（活动）上下文；
this.movieData=对象；
}
@凌驾
公共视图getView（int位置、视图转换视图、视图组父视图）{
视图=转换视图；
视窗座；
如果（视图==null）{
LayoutInflater vi=（LayoutInflater）上下文
.getSystemService（上下文布局\充气机\服务）；
视图=vi.充气（R.layout.list_行，父级，false）；
holder=新的ViewHolder（）；
holder.id=（TextView）view.findViewById（R.id.movieId）；
holder.title=（TextView）view.findViewById（R.id.movieTitle）；
holder.vote_avg=（TextView）view.findViewById（R.id.movieAvg）；
holder.u路径=（图像视图）视图
.findviewbyd（R.id.moviebackground）；
holder.release_date=（TextView）视图
.findviewbyd（R.id.movieRelease）；
holder.original_title=（TextView）视图
.findviewbyd（R.id.movieTitle2）；
holder.vote_count=（TextView）view.findViewById（R.id.movieCount）；
holder.成人=（TextView）view.findViewById（R.id.movie成人）；
holder.poster=（ImageView）view.findViewById（R.id.moviePoster）；
holder.popularity=（TextView）视图
.findviewbyd（R.id.moviePopularity）；
视图.设置标签（支架）；
}否则{
holder=（ViewHolder）view.getTag（）；
}
Movies movie=movieData.get（位置）；
如果（电影！=null）{
//检查每个文本视图是否为空。
//如果没有，请指定一些文本！
holder.id.setText（“id:+movie.getId（））；
holder.title.setText（“title:+movie.getTitle（））；
holder.vote_avg.setText（“vote_avg:+movie.getVote_average（））；
下载位图。下载位图（holder.u路径，
movie.getbackground_path（））；
holder.release\u date.setText（“release\u date:
+movie.getRelease_date（））；
holder.original_title.setText（“original_title:
+movie.getOriginal_title（））；
holder.vote\u count.setText（“vote\u count:+movie.getVote\u count（））；
holder.成人.setText（“成人：+movie.isAdult（））；
下载位图
.downloadBitmap（holder.poster，movie.getPoster_path（））；
holder.popularity.setText（“popularity:+movie.getPopularity（））；
}
返回视图；
}
私有静态类视图持有者{
文本视图id；
文本视图标题；
文本视图平均投票；
ImageView-u路径；
文本视图发布日期；
文本查看原始标题；
TextView投票计数；
文本视图成人；
ImageView海报；
文本视图流行度；
}
}

下载类

package com.example.jdmb;

import java.io.InputStream;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.os.AsyncTask;
import android.widget.ImageView;

public class DownloadBitmap {
    static Bitmap image;

    public static void downloadBitmap(final ImageView imageView,
            final String url) {

        new AsyncTask<Bitmap, Void, Bitmap>() {

            @Override
            protected Bitmap doInBackground(Bitmap... params) {
                HttpRetriever retriever = new HttpRetriever();
                try {                   
                    image = retriever.retrieveBitmap(url);
                } catch (Exception e) {
                }
                return image;

            }

            @Override
            protected void onPostExecute(Bitmap result) {
                super.onPostExecute(result);
                if (imageView != null) {

                    imageView.setImageBitmap(result);
                }
            }

        }.execute();

    }
}

package com.example.jdmb；
导入java.io.InputStream；
导入android.graphics.Bitmap；
导入android.graphics.BitmapFactory；
导入android.graphics.BitmapFactory.Options；
导入android.os.AsyncTask；
导入android.widget.ImageView；
公共类下载位图{
静态位图图像；
公共静态无效下载位图（最终图像视图图像视图，
最终字符串（url）{
新建异步任务（）{
@凌驾
受保护位图doInBackground（位图…参数）{
HttpRetriever retriever=新的HttpRetriever（）；
试试{
image=retriever.retrieveBitmap（url）；
}捕获（例外e）{
}
返回图像；
}
@凌驾
受保护的void onPostExecute（位图结果）{
super.onPostExecute（结果）；
如果（imageView！=null）{
设置图像位图（结果）；
}
}
}.execute（）；
}
}

---

我的代码的哪一部分使我在滚动时看到相同的照片，我认为这与回收图像有关，但不确定如何通过它。

回收的图像视图显示了您告诉它的最后一个位图。您需要在返回视图之前或在执行异步任务时，将holder.background\u path&holder.poster设置为通用资源

像这样：

package com.example.jdmb;

import java.io.InputStream;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.widget.ImageView;

public class DownloadBitmap {
    static Bitmap image;

    public static void downloadBitmap(final ImageView imageView,
            final String url) {

        new AsyncTask<Bitmap, Void, Bitmap>() {

            protected void onPreExecute(){
                //This could also be an internal resource instead of null
                imageView.setImageBitmap(null);
            }

            @Override
            protected Bitmap doInBackground(Bitmap... params) {
                HttpRetriever retriever = new HttpRetriever();
                InputStream is = retriever.retrieveStream(url);
                image = BitmapFactory.decodeStream(is);
                return image;

            }

            @Override
            protected void onPostExecute(Bitmap result) {
                super.onPostExecute(result);
                imageView.setImageBitmap(result);

            }

        }.execute();

    }
}

调整电影适配器构造函数

package com.example.jdmb;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MoviesAdapter extends ArrayAdapter<Movies> {
    private ArrayList<Movies> movieData;
    private Activity context;
    private ImageLoader mImageLoader;

    public MoviesAdapter(Context context, int resource,
            ArrayList<Movies> objects, ImageLoader loader) {
        super(context, resource, objects);
        this.context = (Activity) context;
        this.movieData = objects;
        this.mImageLoader = loader;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        ViewHolder holder;
        if (view == null) {
            LayoutInflater vi = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = vi.inflate(R.layout.list_row, parent, false);
            holder = new ViewHolder();
            holder.id = (TextView) view.findViewById(R.id.movieId);
            holder.title = (TextView) view.findViewById(R.id.movieTitle);
            holder.vote_avg = (TextView) view.findViewById(R.id.movieAvg);
            holder.backdrop_path = (ImageView) view
                    .findViewById(R.id.movieBackdrop);
            holder.release_date = (TextView) view
                    .findViewById(R.id.movieRelease);
            holder.original_title = (TextView) view
                    .findViewById(R.id.movieTitle2);
            holder.vote_count = (TextView) view.findViewById(R.id.movieCount);
            holder.adult = (TextView) view.findViewById(R.id.movieAdult);
            holder.poster = (ImageView) view.findViewById(R.id.moviePoster);
            holder.popularity = (TextView) view
                    .findViewById(R.id.moviePopularity);
            view.setTag(holder);

        } else {
            holder = (ViewHolder) view.getTag();

        }
        Movies movie = movieData.get(position);

        if (movie != null) {
            // check to see if each individual textview is null.
            // if not, assign some text!

            holder.id.setText("id: " + movie.getId());
            holder.title.setText("title: " + movie.getTitle());
            holder.vote_avg.setText("vote_avg: " + movie.getVote_average());
            mImageLoader.get(movie.getBackdrop_path(), holder.backdrop_path);
            holder.release_date.setText("release_date: "
                    + movie.getRelease_date());
            holder.original_title.setText("original_title: "
                    + movie.getOriginal_title());
            holder.vote_count.setText("vote_count: " + movie.getVote_count());
            holder.adult.setText("adult: " + movie.isAdult());
            mImageLoader.get(movie.getPoster_path(), holder.poster);
            holder.popularity.setText("popularity: " + movie.getPopularity());
        }
        return view;
    }

    private static class ViewHolder {
        TextView id;
        TextView title;
        TextView vote_avg;
        ImageView backdrop_path;
        TextView release_date;
        TextView original_title;
        TextView vote_count;
        TextView adult;
        ImageView poster;
        TextView popularity;
    }
}

package com.example.jdmb；
导入java.util.ArrayList；
导入android.app.Activity；
导入android.content.Context；
导入android.view.LayoutInflater；
导入android.view.view；
导入android.view.ViewGroup；
导入android.widget.ArrayAdapter；
导入android.widget.ImageView；
导入android.widget.TextView；
公共类MoviesAdapter扩展了ArrayAdapter{
私有ArrayList电影数据；
私人活动语境；
私有图像加载器；
公共MoviesAdapter（上下文、int资源、，
@Override
public void onCreate(Bundle savedInstanceState){
...
ImageLoader mImageLoader = new ImageLoader(this, R.drawable.default_image);
MoviesAdapter  mMoviesAdapter = new MoviesAdapter(this, R.layout.your_list_layout, moviesList, mImageLoader);
...
}

package com.example.jdmb;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class MoviesAdapter extends ArrayAdapter<Movies> {
    private ArrayList<Movies> movieData;
    private Activity context;
    private ImageLoader mImageLoader;

    public MoviesAdapter(Context context, int resource,
            ArrayList<Movies> objects, ImageLoader loader) {
        super(context, resource, objects);
        this.context = (Activity) context;
        this.movieData = objects;
        this.mImageLoader = loader;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        ViewHolder holder;
        if (view == null) {
            LayoutInflater vi = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = vi.inflate(R.layout.list_row, parent, false);
            holder = new ViewHolder();
            holder.id = (TextView) view.findViewById(R.id.movieId);
            holder.title = (TextView) view.findViewById(R.id.movieTitle);
            holder.vote_avg = (TextView) view.findViewById(R.id.movieAvg);
            holder.backdrop_path = (ImageView) view
                    .findViewById(R.id.movieBackdrop);
            holder.release_date = (TextView) view
                    .findViewById(R.id.movieRelease);
            holder.original_title = (TextView) view
                    .findViewById(R.id.movieTitle2);
            holder.vote_count = (TextView) view.findViewById(R.id.movieCount);
            holder.adult = (TextView) view.findViewById(R.id.movieAdult);
            holder.poster = (ImageView) view.findViewById(R.id.moviePoster);
            holder.popularity = (TextView) view
                    .findViewById(R.id.moviePopularity);
            view.setTag(holder);

        } else {
            holder = (ViewHolder) view.getTag();

        }
        Movies movie = movieData.get(position);

        if (movie != null) {
            // check to see if each individual textview is null.
            // if not, assign some text!

            holder.id.setText("id: " + movie.getId());
            holder.title.setText("title: " + movie.getTitle());
            holder.vote_avg.setText("vote_avg: " + movie.getVote_average());
            mImageLoader.get(movie.getBackdrop_path(), holder.backdrop_path);
            holder.release_date.setText("release_date: "
                    + movie.getRelease_date());
            holder.original_title.setText("original_title: "
                    + movie.getOriginal_title());
            holder.vote_count.setText("vote_count: " + movie.getVote_count());
            holder.adult.setText("adult: " + movie.isAdult());
            mImageLoader.get(movie.getPoster_path(), holder.poster);
            holder.popularity.setText("popularity: " + movie.getPopularity());
        }
        return view;
    }

    private static class ViewHolder {
        TextView id;
        TextView title;
        TextView vote_avg;
        ImageView backdrop_path;
        TextView release_date;
        TextView original_title;
        TextView vote_count;
        TextView adult;
        ImageView poster;
        TextView popularity;
    }
}