实现功能：
在MyMusicListFragment中实现专辑封面图片
在item_music_list中实现专辑封面图片
实现效果如图：
实现代码如下：
在MediaUtiles中添加如下代码：
/*** 获取默认专辑图片*/public static Bitmap getDefaultArtwork(Context context,boolean small) {BitmapFactory.Options opts = new BitmapFactory.Options();opts.inPreferredConfig = Bitmap.Config.RGB_565;if(small){//返回小图片return BitmapFactory.decodeStream(context.getResources().openRawResource(R.mipmap.music), null, opts);}return BitmapFactory.decodeStream(context.getResources().openRawResource(R.mipmap.music), null, opts);}/*** 从文件当中获取专辑封面位图*/private static Bitmap getArtworkFromFile(Context context, long songid, long albumid){Bitmap bm = null;if(albumid < 0 && songid < 0) {throw new IllegalArgumentException("Must specify an album or a song id");}try {BitmapFactory.Options options = new BitmapFactory.Options();FileDescriptor fd = null;if(albumid < 0){Uri uri = Uri.parse("content://media/external/audio/media/"+ songid + "/albumart");ParcelFileDescriptor pfd = context.getContentResolver().openFileDescriptor(uri, "r");if(pfd != null) {fd = pfd.getFileDescriptor();}} else {Uri uri = ContentUris.withAppendedId(albumArtUri, albumid);ParcelFileDescriptor pfd = context.getContentResolver().openFileDescriptor(uri, "r");if(pfd != null) {fd = pfd.getFileDescriptor();}}options.inSampleSize = 1;// 只进行大小判断options.inJustDecodeBounds = true;// 调用此方法得到options得到图片大小BitmapFactory.decodeFileDescriptor(fd, null, options);// 我们的目标是在800pixel的画面上显示// 所以需要调用computeSampleSize得到图片缩放的比例options.inSampleSize = 100;// 我们得到了缩放的比例，现在开始正式读入Bitmap数据options.inJustDecodeBounds = false;options.inDither = false;options.inPreferredConfig = Bitmap.Config.ARGB_8888;//根据options参数，减少所需要的内存bm = BitmapFactory.decodeFileDescriptor(fd, null, options);} catch (FileNotFoundException e) {e.printStackTrace();}return bm;}/*** 获取专辑封面位图对象*/public static Bitmap getArtwork(Context context, long song_id, long album_id, boolean allowdefalut, boolean small){if(album_id < 0) {if(song_id < 0) {Bitmap bm = getArtworkFromFile(context, song_id, -1);if(bm != null) {return bm;}}if(allowdefalut) {return getDefaultArtwork(context, small);}return null;}ContentResolver res = context.getContentResolver();Uri uri = ContentUris.withAppendedId(albumArtUri, album_id);if(uri != null) {InputStream in = null;try {in = res.openInputStream(uri);BitmapFactory.Options options = new BitmapFactory.Options();//先制定原始大小options.inSampleSize = 1;//只进行大小判断options.inJustDecodeBounds = true;//调用此方法得到options得到图片的大小BitmapFactory.decodeStream(in, null, options);/** 我们的目标是在你N pixel的画面上显示。 所以需要调用computeSampleSize得到图片缩放的比例 **//** 这里的target为800是根据默认专辑图片大小决定的，800只是测试数字但是试验后发现完美的结合 **/if(small){options.inSampleSize = computeSampleSize(options, 40);} else{options.inSampleSize = computeSampleSize(options, 600);}// 我们得到了缩放比例，现在开始正式读入Bitmap数据options.inJustDecodeBounds = false;options.inDither = false;options.inPreferredConfig = Bitmap.Config.ARGB_8888;in = res.openInputStream(uri);return BitmapFactory.decodeStream(in, null, options);} catch (FileNotFoundException e) {Bitmap bm = getArtworkFromFile(context, song_id, album_id);if(bm != null) {if(bm.getConfig() == null) {bm = bm.copy(Bitmap.Config.RGB_565, false);if(bm == null && allowdefalut) {return getDefaultArtwork(context, small);}}} else if(allowdefalut) {bm = getDefaultArtwork(context, small);}return bm;} finally {try {if(in != null) {in.close();}} catch (IOException e) {e.printStackTrace();}}}return null;}/*** 对图片进行合适的缩放*/public static int computeSampleSize(Options options, int target) {int w = options.outWidth;int h = options.outHeight;int candidateW = w / target;int candidateH = h / target;int candidate = Math.max(candidateW, candidateH);if(candidate == 0) {return 1;}if(candidate > 1) {if((w > target) && (w / candidate) < target) {candidate -= 1;}}if(candidate > 1) {if((h > target) && (h / candidate) < target) {candidate -= 1;}}return candidate;}
在MyMusicListFragment中添加如下代码：
//回调播放状态下的UI设置public void changeUIStatusOnPlay(int position){//更新UI状态--当前播放的音乐,传进来当前音乐的下标if (position>=0 && position<mp3Infos.size()){Mp3Info mp3Info = mp3Infos.get(position);//获取音乐信息textView_songName.setText(mp3Info.getTitle());//设置歌名textView2_singer.setText(mp3Info.getArtist());//设置歌手名//imageView2_play_pause.setImageResource(R.mipmap.player_btn_pusr_normal);//更新播放暂停图片//获取专辑封面图片Bitmap albumBitmap = MediaUtils.getArtwork(mainActivity,mp3Info.getId(),mp3Info.getAlbumId(),true,true);//改变播放界面专辑封面图片imageView_album.setImageBitmap(albumBitmap);}}
完整的MyMusicListAdapter修改为如下代码：
package com.iwanghang.drmplayer.adapter;import android.content.Context;import android.graphics.Bitmap;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.TextView;import com.iwanghang.drmplayer.MyMusicListFragment;import com.iwanghang.drmplayer.R;import com.iwanghang.drmplayer.utils.MediaUtils;import com.iwanghang.drmplayer.vo.Mp3Info;import java.util.ArrayList;/*** 自定义的音乐列表适配器* 为了方便扩展，因为之前没有考虑到显示专辑封面* Created by iwanghang on 16/4/16.*/public class MyMusicListAdapter extends BaseAdapter{private Context ctx; //上下文对象引用private ArrayList<Mp3Info> mp3Infos;//存放Mp3Info引用的集合private Mp3Info mp3Info;//Mp3Info对象引用private int pos = -1;//列表位置/*** 构造函数* @param ctx上下文* @param mp3Infos 集合对象*/public MyMusicListAdapter(Context ctx, ArrayList<Mp3Info> mp3Infos){this.ctx = ctx;this.mp3Infos = mp3Infos;System.out.println("MyMusicListAdapter.java #0 : ctx = " + ctx + ",mp3Infos = " + mp3Infos.size());}public ArrayList<Mp3Info> getMp3Infos() {System.out.println("MyMusicListAdapter.java #1 : public ArrayList<Mp3Info> getMp3Infos() {");return mp3Infos;}public void setMp3Infos(ArrayList<Mp3Info> mp3Infos) {System.out.println("MyMusicListAdapter.java #2 : public void setMp3Infos(ArrayList<Mp3Info> mp3Infos) {");this.mp3Infos = mp3Infos;}@Overridepublic int getCount() {//System.out.println("MyMusicListAdapter.java #3 : public int getCount() {" + mp3Infos.size());//return mp3Infos.size();return mp3Infos.size();}@Overridepublic Object getItem(int position) {System.out.println("MyMusicListAdapter.java #4 : public Object getItem(int position) {");return mp3Infos.get(position);}@Overridepublic long getItemId(int position) {//System.out.println("MyMusicListAdapter.java #5 : public long getItemId(int position) {");return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {//System.out.println("MyMusicListAdapter.java #6 : public View getView ");ViewHolder vh;if(convertView==null){//vh = new ViewHolder();convertView = LayoutInflater.from(ctx).inflate(R.layout.item_music_list,null);vh = new ViewHolder();vh.textView1_title = (TextView) convertView.findViewById(R.id.textView1_title);vh.textView2_singer = (TextView) convertView.findViewById(R.id.textView2_singer);vh.textView3_time = (TextView) convertView.findViewById(R.id.textView3_time);vh.imageView1_ablum = (ImageView) convertView.findViewById(R.id.imageView1_ablum);//System.out.println("MyMusicListAdapter.java #7 : textView1_title = " + vh.textView1_title);convertView.setTag(vh);//表示给View添加一个格外的数据，}else {vh = (ViewHolder)convertView.getTag();//通过getTag的方法将数据取出来}Mp3Info mp3Info = mp3Infos.get(position);vh.textView1_title.setText(mp3Info.getTitle());//显示标题vh.textView2_singer.setText(mp3Info.getArtist());//显示歌手vh.textView3_time.setText(MediaUtils.formatTime(mp3Info.getDuration()));//显示时长//获取专辑封面图片Bitmap albumBitmapItem = MediaUtils.getArtwork(ctx,mp3Info.getId(),mp3Info.getAlbumId(),true,true);System.out.println("MyMusicListAdapter.java #8 : albumBitmapItem = " + albumBitmapItem.getConfig());//改变播放界面专辑封面图片vh.imageView1_ablum.setImageBitmap(albumBitmapItem);//vh.imageView1_ablum.setImageResource(R.mipmap.music);return convertView;}/*** 定义一个内部类* 声明相应的控件引用*/static class ViewHolder{//所有控件对象引用TextView textView1_title;//标题TextView textView2_singer;//歌手TextView textView3_time;//时长ImageView imageView1_ablum;//专辑封面图片}}//inflate(R.layout.item_music_list,null);
