Question

好的，所以我正在尝试在我的应用中显示歌曲的专辑封面。我试图通过使用Mediametadataretriever来做到这一点。但是我在第metaRetriver.setDataSource(Environment.getExternalStorageDirectory().getPath() );行中遇到了IllegalStateException 我理解这可能是因为使用了无效路径，但我无法弄清楚那是什么有效路径。我真的是Android应用程序开发的新手。任何人都可以帮助我吗？

PlayListActivity.java：

package com.example.dell_1.myapp3;


import android.app.Activity;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.media.MediaMetadataRetriever;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
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 java.io.IOException;

public class PlayListActivity extends Activity {

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

    MediaMetadataRetriever metaRetriver;
    byte[] art;
    ImageView album_art;


    @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();
        acv();
    }

    public void acv() {
        getInit();

        metaRetriver = new MediaMetadataRetriever();
        metaRetriver.setDataSource(Environment.getExternalStorageDirectory().getPath() );
        try {
            art = metaRetriver.getEmbeddedPicture();
            Bitmap songImage = BitmapFactory.decodeByteArray(art, 0, art.length);
            album_art.setImageBitmap(songImage);
        } catch (Exception e) {
            album_art.setBackgroundColor(Color.GRAY);

        }

    }

    public void getInit() {
        album_art = (ImageView) findViewById(R.id.coverart);

    }
}

activity_play_list.xml ：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">

    <ListView
        android:id="@+id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:divider="#242424"
        android:dividerHeight="1dp"
        android:listSelector="@drawable/list_selector" />

</LinearLayout>

activity_android_building_music_player.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <LinearLayout
        android:id="@+id/player_header_bg"
        android:layout_width="fill_parent"
        android:layout_height="60dip"
        android:layout_alignParentTop="true"
        android:background="@layout/bg_player_header"
        android:paddingLeft="5dp"
        android:paddingRight="5dp">

        <TextView
            android:id="@+id/songTitle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:layout_weight="1"
            android:paddingLeft="50dp"
            android:text="The Good"
            android:textColor="#04b3d2"
            android:textSize="16dp"
            android:textStyle="bold" />

        <ImageButton
            android:id="@+id/btnPlaylist"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:background="@null"
            android:src="@drawable/btn_playlist" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/songThumbnail"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/player_header_bg"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:gravity="center"
        android:paddingBottom="10dp"
        android:paddingTop="10dp">

        <ImageView
            android:id="@+id/coverart"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/player_footer_bg"
        android:layout_width="fill_parent"
        android:layout_height="100dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:background="@layout/bg_player_footer"
        android:gravity="center">

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:gravity="center_vertical"
            android:orientation="horizontal"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:weightSum="1">
            <RelativeLayout
                android:layout_width="300dp"
                android:layout_height="match_parent">
                <ImageButton
                    android:id="@+id/btnPrevious"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="2.40"
                    android:layout_alignParentLeft="true"
                    android:paddingLeft="10dp"
                    android:background="@null"
                    android:src="@drawable/btn_previous" />

                <ImageButton
                    android:id="@+id/btnPlay1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_centerInParent="true"
                    android:background="@null"
                    android:src="@drawable/btn_play"
                    android:onClick="buttonAction1"/>


                <ImageButton
                    android:id="@+id/btnNext"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:paddingLeft="250dp"
                    android:background="@null"
                    android:src="@drawable/btn_next" />
            </RelativeLayout>
        </LinearLayout>
    </LinearLayout>

    <SeekBar
        android:id="@+id/songProgressBar"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@+id/player_footer_bg"
        android:layout_alignLeft="@+id/timerDisplay"
        android:layout_alignStart="@+id/timerDisplay"
        android:layout_marginBottom="10dp"
        android:paddingLeft="6dp"
        android:paddingRight="6dp"
        android:progressDrawable="@drawable/seekbar_progress"
        android:thumb="@drawable/download8" />

    <LinearLayout
        android:id="@+id/timerDisplay"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@id/songProgressBar"
        android:layout_marginBottom="10dp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp">

        <TextView
            android:id="@+id/songCurrentDurationLabel"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="left"
            android:textColor="#eeeeee"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/songTotalDurationLabel"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:gravity="right"
            android:textColor="#04cbde"
            android:textStyle="bold" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@id/timerDisplay"
        android:gravity="center">

        <ImageButton
            android:id="@+id/btnRepeat"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginRight="5dp"
            android:background="@null"
            android:src="@drawable/btn_repeat" />

        <ImageButton
            android:id="@+id/btnShuffle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:background="@null"
            android:src="@drawable/btn_shuffle" />
    </LinearLayout>
</RelativeLayout>

Answer 1

您正在尝试从特定文件中获取缩略图，但您正在放入外部存储目录的路径。所以通过使用

metaRetriver.setDataSource(Environment.getExternalStorageDirectory().getPath() );

您指向的是文件夹，而不是特定的媒体文件。但是这个：

metaRetriver.setDataSource(Environment.getExternalStorageDirectory().getPath() + "yourFileName.mp3" );

更符合您的需求。

Answer 2

实际上你正在一个文件路径中播放一些，并且你正试图从外部存储文件路径中获取艺术作品，所以你应该将路径发送到该方法，

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();
        acv(path);
    }

    public void acv(String path) {
        getInit();

        metaRetriver = new MediaMetadataRetriever();
        metaRetriver.setDataSource(path);
        try {
            art = metaRetriver.getEmbeddedPicture();
            Bitmap songImage = BitmapFactory.decodeByteArray(art, 0, art.length);
            album_art.setImageBitmap(songImage);
        } catch (Exception e) {
            album_art.setBackgroundColor(Color.GRAY);

        }

    }

很少有建议，

您不应该在我知道您使用2个布局的活动中多次使用setContentView，但在这种情况下，您应该使用2个不同的活动。
您播放的歌曲和用户不会在您的应用中，他们总是喜欢在应用程序中移动，所以尝试使用服务在后台运行歌曲

如需更多参考，您可以在Github中获得精彩的开源应用程序。

使用mediametadataretriever显示专辑封面

2 个答案: