java - 如何正确添加监听器以进行 Glide

我正在使用 Glide 来显示专辑封面，但是以某种方式我无法显示它。我想添加监听器以滑动查找错误，但无法正常工作。它显示错误信息:



PlayListActivity.java :

package com.example.dell_1.myapp3;


import android.app.Activity;
import android.database.Cursor;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.design.widget.Snackbar;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.Toast;

import java.io.File;
import java.io.IOException;

import com.bumptech.glide.Glide;
import com.bumptech.glide.load.resource.drawable.GlideDrawable;
import com.bumptech.glide.request.RequestListener;
import com.bumptech.glide.request.target.Target;


public class PlayListActivity extends Activity {

    private String[] mAudioPath;
    private MediaPlayer mMediaPlayer;
    private String[] mMusicList;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_play_list);

        mMediaPlayer = new MediaPlayer();
        ListView mListView = (ListView) findViewById(R.id.list);

        mMusicList = getAudioList();

        ArrayAdapter<String> mAdapter = new ArrayAdapter<>(this,
                android.R.layout.simple_list_item_1, mMusicList);
        mListView.setAdapter(mAdapter);

        mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View view, int arg2,
                                    long arg3) {

                try {
                    playSong(mAudioPath[arg2]);
                } catch (IllegalArgumentException e) {
                    e.printStackTrace();
                } catch (IllegalStateException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }
        });
    }

    private String[] getAudioList() {
        final Cursor mCursor = getContentResolver().query(
                MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                new String[]{MediaStore.Audio.Media.DISPLAY_NAME, MediaStore.Audio.Media.DATA}, null, null,
                "LOWER(" + MediaStore.Audio.Media.TITLE + ") ASC");

        int count = mCursor.getCount();

        String[] songs = new String[count];
        mAudioPath = new String[count];
        int i = 0;
        if (mCursor.moveToFirst()) {
            do {
                songs[i] = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME));
                mAudioPath[i] = mCursor.getString(mCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA));
                i++;
            } while (mCursor.moveToNext());
        }

        mCursor.close();

        return songs;
    }

    private void playSong(String path) throws IllegalArgumentException,
            IllegalStateException, IOException {

        setContentView(R.layout.activity_android_building_music_player);
        Log.d("ringtone", "playSong :: " + path);

        mMediaPlayer.reset();
        mMediaPlayer.setDataSource(path);
//mMediaPlayer.setLooping(true);
        mMediaPlayer.prepare();
        mMediaPlayer.start();

        asd();
    }

    public void asd(){
        File music = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC);
// Tested with music from Windows 7's c:\Users\Public\Music\Sample Music
        String mAudioPath = new File(music, "Maid with the Flaxen Hair.mp3").getAbsolutePath();
        ImageView imageView = (ImageView) findViewById(R.id.coverart);
        Glide
                .with(this)
                .load(new AudioCover(mAudioPath))
                .placeholder(R.drawable.adele1)
                .error(R.drawable.adele1)
                .listener(new RequestListener<Uri, GlideDrawable>() {
                    @Override public boolean onException(Exception e, Uri model, Target<GlideDrawable> target, boolean isFirstResource) {
                        return false;
                    }
                    @Override public boolean onResourceReady(GlideDrawable resource, Uri model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
                        // easy
                        return false;
                        // impossible?
                    }
                })
                .into(imageView)
        ;
    }
}

AudioCover.java:

package com.example.dell_1.myapp3;

import android.content.Context;
import android.media.MediaMetadataRetriever;

import com.bumptech.glide.*;
import com.bumptech.glide.load.data.DataFetcher;
import com.bumptech.glide.load.model.GenericLoaderFactory;
import com.bumptech.glide.load.model.ModelLoader;
import com.bumptech.glide.load.model.ModelLoaderFactory;
import com.bumptech.glide.load.model.stream.StreamModelLoader;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

public class AudioCover {
    final String path;
    public AudioCover(String path) {
        this.path = path;
    }
}

class AudioCoverLoader implements StreamModelLoader<AudioCover> {
    @Override public DataFetcher<InputStream> getResourceFetcher(AudioCover model, int width, int height) {
        return new AudioCoverFetcher(model);
    }

    static class Factory implements ModelLoaderFactory<AudioCover, InputStream> {
        @Override public ModelLoader<AudioCover, InputStream> build(Context context, GenericLoaderFactory factories) {
            return new AudioCoverLoader();
        }
        @Override public void teardown() {
        }
    }
}
class AudioCoverFetcher implements DataFetcher<InputStream> {
    private final AudioCover model;
    private FileInputStream stream;

    public AudioCoverFetcher(AudioCover model) {
        this.model = model;
    }

    @Override public String getId() {
        return model.path;
    }

    @Override public InputStream loadData(Priority priority) throws Exception {
        MediaMetadataRetriever retriever = new MediaMetadataRetriever();
        try {
            retriever.setDataSource(model.path);
            byte[] picture = retriever.getEmbeddedPicture();
            if (picture != null) {
                return new ByteArrayInputStream(picture);
            } else {
                return fallback(model.path);
            }
        } finally {
            retriever.release();
        }
    }

    private static final String[] FALLBACKS = {"cover.jpg", "album.jpg", "folder.jpg"};
    private InputStream fallback(String path) throws FileNotFoundException {
        File parent = new File(path).getParentFile();
        for (String fallback : FALLBACKS) {
            // TODO make it smarter by enumerating folder contents and filtering for files
            // example algorithm for that: http://askubuntu.com/questions/123612/how-do-i-set-album-artwork
            File cover = new File(parent, fallback);
            if (cover.exists()) {
                return stream = new FileInputStream(cover);
            }
        }
        return null;
    }

    @Override public void cleanup() {
        // already cleaned up in loadData and ByteArrayInputStream will be GC'd
        if (stream != null) {
            try {
                stream.close();
            } catch (IOException ignore) {
                // can't do much about it
            }
        }
    }
    @Override public void cancel() {
        // cannot cancel
    }
}

最佳答案

RequestListener<T, R>期望T成为您在load()中提供的模型，在您的情况下为T = ? super AudioCover(documentation):

// ...
.listener(new RequestListener<AudioCover, GlideDrawable>() {
    @Override
    public boolean onException(Exception e, AudioCover model, Target<GlideDrawable> target, boolean isFirstResource) {
        return false;
    }

    @Override
    public boolean onResourceReady(GlideDrawable resource, AudioCover model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
        return false;
    }
})
// ...

请注意，由于不建议使用4.0.0-RC0 RequestListener<T, R>版本，而推荐使用RequestListener<R>，请在新的javadoc中找到更多信息。