android获取音乐文件的内置专辑图片实现思路及代码

代码和注释如下：

private cursor getcursor(string filepath) {
string path = null;
cursor c = getcontentresolver().query(
mediastore.audio.media.external_content_uri, null, null, null,
mediastore.audio.media.default_sort_order);
// system.out.println(c.getstring(c.getcolumnindex("_data")));
if (c.movetofirst()) {
do {
// 通过cursor 获取路径，如果路径相同则break；
system.out.println("////////"+filepath);
path = c.getstring(c
.getcolumnindexorthrow(mediastore.audio.media.data));
system.out.println("?????????"+path);
// 查找到相同的路径则返回，此时cursorposition 便是指向路径所指向的cursor 便可以返回了
if (path.equals(filepath)) {
// system.out.println("audiopath = " + path);
// system.out.println("filepath = " + filepath);
// cursorposition = c.getposition();
break;
}
} while (c.movetonext());
}
// 这两个没有什么作用，调试的时候用
// string audiopath = c.getstring(c
// .getcolumnindexorthrow(mediastore.audio.media.data));
//
// system.out.println("audiopath = " + audiopath);
return c;
}
private string getalbumart(int album_id) {
string murialbums = "content://media/external/audio/albums";
string[] projection = new string[] { "album_art" };
cursor cur = this.getcontentresolver().query(
uri.parse(murialbums + "/" + integer.tostring(album_id)),
projection, null, null, null);
string album_art = null;
if (cur.getcount() > 0 && cur.getcolumncount() > 0) {
cur.movetonext();
album_art = cur.getstring(0);
}
cur.close();
cur = null;
return album_art;
}
private void getimage(){
cursor currentcursor = getcursor("/mnt/sdcard/"+mp3info);
int album_id = currentcursor.getint(currentcursor
.getcolumnindexorthrow(mediastore.audio.media.album_id));
string albumart = getalbumart(album_id);
bitmap bm = null;
if (albumart == null) {
mimageview.setbackgroundresource(r.drawable.staring);
} else {
bm = bitmapfactory.decodefile(albumart);
bitmapdrawable bmpdraw = new bitmapdrawable(bm);
mimageview.setimagedrawable(bmpdraw);
}
}