图片载入速度非常慢

问题描述

我正在从电影数据库API中获取数据，有时图像无法加载，有时加载缓慢。 我正在将图片网址解码为位图，然后使用适配器将其设置为图片视图。请告诉我在哪里出错。我正在从API获取图片网址。 MainActivity.java：

package com.example.sahilshokeen.movie;

public class MainActivity extends Activity {
private RecyclerView recyclerView;
private GridLayoutManager manager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //checking network
    ConnectivityManager connMgr = (ConnectivityManager)
            getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
    if (networkInfo != null && networkInfo.isConnected()) {
        // fetch data
        new FetchData().execute();
        new Convert().execute();
    } else {
        // display error
        Toast toast = Toast.makeText(this, "No Network", Toast.LENGTH_LONG);
        toast.show();
    }
    //setting adapter
    recyclerView = (RecyclerView) findViewById(R.id.recyclers);
    manager = new GridLayoutManager(MainActivity.this, 2);
    recyclerView.setAdapter(new Adapter());
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(manager);
}

public class FetchData extends AsyncTask<Void, Void, Void> {
    private HttpURLConnection connection = null;
    private BufferedReader reader = null;
    private String json;
    private String urlString = "http://api.themoviedb.org/3/movie/popular?api_key=b6f6fcfbb225d8c500e4404655ccadcc&certification=G";
    private String image = " http://image.tmdb.org/t/p/w92/";

    @Override
    protected Void doInBackground(Void... params) {
        //connecting to network
        try {
            URL url = new URL(urlString);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.connect();
            StringBuffer buffer = new StringBuffer();
            InputStream stream = connection.getInputStream();
            reader = new BufferedReader(new InputStreamReader(stream));
            String line;
            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }
            json = buffer.toString();
            //getting json data
            try {
                JSONObject object = new JSONObject(json);
                JSONArray array = object.getJSONArray("results");
                for (int i = 0; i < 6; i++) {
                    Data.objects[i] = array.getJSONObject(i);
                    Data.title[i] = Data.objects[i].getString("original_title");
                    Data.overview[i] = Data.objects[i].getString("overview");
                    Data.date[i] = Data.objects[i].getString("release_date");
                    Data.image[i] = Data.objects[i].getString("poster_path");
                    Data.vote[i] = Data.objects[i].getDouble("vote_average");
                    Data.image[i] = image + Data.image[i];
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            connection.disconnect();
        }
        try {
            if (reader != null) {
                reader.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

}

public class Convert extends AsyncTask<Void, Void, Void>{

    @Override
    protected Void doInBackground(Void... params) {
        for(int i=0;i<6;i++) {
            try {
                URL url = new URL(Data.image[i]);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setDoInput(true);
                connection.connect();
                InputStream input = connection.getInputStream();
                Bitmap myBitmap = BitmapFactory.decodeStream(input);
                Data.bImage[i] = myBitmap;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

}

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        if (id == R.id.action_refresh) {

            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Adapter.java：

package com.example.sahilshokeen.movie;

public class Adapter extends RecyclerView.Adapter<Adapter.Holder> {

public static class Holder extends RecyclerView.ViewHolder {
    public CardView cardView;
    public ImageView imageView;

    public Holder(View itemView) {
        super(itemView);
        cardView = (CardView) itemView.findViewById(R.id.card);
        imageView = (ImageView) itemView.findViewById(R.id.images);
    }
}

@Override
public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.grid_item, parent, false);
    Holder holder = new Holder(view);
    return holder;
}

@Override
public void onBindViewHolder(Holder holder, int position) {
    holder.imageView.setImageBitmap(Data.bImage[position]);
}

@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
}

@Override
public int getItemCount() {
    return Data.bImage.length;
}

 }

Data.java：

package com.example.sahilshokeen.movie;

public class Data {
public static JSONObject[] objects = new JSONObject[6];
public static String[] title = new String[6];
public static String[] overview = new String[6];
public static String[] date = new String[6];
public static String[] image = new String[6];
public static Bitmap[] bImage = new Bitmap[6];
public static Double[] vote = new Double[6];
}

使用诸如Glide或Picasso之类的库！

    @Override
    public void onBindViewHolder(Holder holder, int position) {
       // holder.imageView.setImageBitmap(Data.bImage[position]);


   Glide.with(ctx)
                    .load(imageDownloadUrl)
                    .into(holder.imageView);

 Picasso.with(context).load("").placeholder(Data.bImage[position]).into(holder.imageView);

or
                            //R.drawable.drawableName
Picasso.with(context).load(Data.bImage[position]).into(holder.imageView);    

}

       compile 'com.squareup.picasso:picasso:2.5.2'

      compile 'com.github.bumptech.glide:glide:3.6.1'

        compile 'com.android.support:support-v4:25.1.0'