基於android的網路音樂播放器-播放音樂及收藏音樂的效果展示（四）
阿新 • • 發佈：2019-01-31
作為android初學者，最近把瘋狂android講義和瘋狂Java講義看了一遍，看到書中介紹的知識點非常多，很難全部記住，為了更好的掌握基礎知識點，我將開發一個網路音樂播放器-EasyMusic來鞏固下，也當作是練練手。感興趣的朋友可以看看，有設計不足的地方也歡迎指出。
開發之前首先介紹下該音樂播放器將要開發的功能（需求）：
1.本地音樂的載入和播放；
2.網路音樂的搜尋，試聽和下載；
3.音樂的斷點下載；
4.點選播放圖示載入專輯圖片，點選歌詞載入歌詞並滾動顯示（支援滑動歌詞改變音樂播放進度）；
5.支援基於popupWindow的彈出式選單；
6.支援後臺工作列顯示和控制。
該篇主要是貼上一些關鍵類的程式碼以及音樂播放器的展示效果圖：
首先看下效果圖：
1>收藏音樂：
2>取消收藏：
然後主要程式碼如下：
1.MainActivity.java
package com.sprd.easymusic;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import com.sprd.easymusic.fragment.DownloadFragment;
import MainActivity主要負責管理整個音樂播放器應用，像資料庫查詢，服務啟動等都是該類負責。其佈局為：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.sprd.easymusic.MainActivity" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:background="#18f" >
<TextView
android:id="@+id/fragment1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="@string/title_section1"/>
<TextView
android:id="@+id/fragment2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="@string/title_section2"/>
<TextView
android:id="@+id/fragment3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="@string/title_section3"/>
<TextView
android:id="@+id/fragment4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:text="@string/title_section4"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="3dp"
android:gravity="center" >
<!-- 該textview作為紅線移動到當前fragment下 -->
<TextView
android:id="@+id/fragmentTitle"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:background="#f00" />
<TextView
android:id="@+id/textView6"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="3" />
</LinearLayout>
<android.support.v4.view.ViewPager
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="20"
android:alpha="0.8"
android:background="#afeeee"
tools:context=".MainActivity" >
</android.support.v4.view.ViewPager>
</LinearLayout>2.MusicListFragment.java
package com.sprd.easymusic.fragment;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.sprd.easymusic.R;
import com.sprd.easymusic.mysql.MyDBHelper;
import com.sprd.easymusic.myview.RefreshableListView;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.support.v4.app.Fragment;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MusicListFragment extends Fragment {
private final String TAG = "MusicListFragment";
private final String ACTION_REFRESH = "action.refreshmusicList";
private List<Map<String, Object>> dbMusic = new ArrayList<>();
private List<Map<String, Object>> storedMusic = new ArrayList<>();
private ListView musicListView;
private LayoutInflater inflater;
private CallBack mCallBack;
private Context mContext;
private MyDBHelper myHelper;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate");
mContext = this.getActivity();
myHelper = new MyDBHelper(mContext, "easyMusic.db3", null, 1);
inflater = LayoutInflater.from(mContext);
dbMusic = mCallBack.getAllMusic();
storedMusic = mCallBack.getStoredMusic();
}
// NetFragment向外界展示的內容，返回值為view
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.musiclist, container, false);
musicListView = (ListView) view.findViewById(R.id.musicList);
musicListView.setAdapter(musicListAdapter);
musicListView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
mCallBack.onItemSelected((String) dbMusic.get(position).get("url"));
TextView title = (TextView) view.findViewWithTag("title");
Toast.makeText(mContext,"title = " + title.getText().toString(),Toast.LENGTH_SHORT).show();
}
});
return view;
}
// 音樂列表介面卡
private BaseAdapter musicListAdapter = new BaseAdapter() {
@Override
public int getCount() {
return dbMusic.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View view = convertView;
Map<String, Object> item = dbMusic.get(position);
if (convertView == null) {
view = inflater.inflate(R.layout.musiclist_item, null);
}
final ImageView storeMusic = (ImageView) view.findViewById(R.id.love);
if (checkIfStored((String) item.get("url"))) {
storeMusic.setImageResource(android.R.drawable.btn_star_big_on);
} else {
storeMusic.setImageResource(android.R.drawable.btn_star_big_off);
}
storeMusic.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
new MyAsyncTask(storeMusic, dbMusic.get(position)).execute();
}
});
TextView musicTitle = (TextView) view.findViewById(R.id.musicTitle);
musicTitle.setTag("title");
TextView musicArtist = (TextView) view.findViewById(R.id.musicArtist);
musicTitle.setText((String) item.get("title"));
musicArtist.setText((String) item.get("artist"));
return view;
}
};
// 檢查當前歌曲是否在收藏列表中，在收藏列表返回true，否則返回false
protected boolean checkIfStored(String url) {
for (Map<String, Object> map : storedMusic) {
if (url.equals((String) map.get("url"))) {
return true;
}
}
return false;
}
// 執行收藏或者取消收藏動作後重新整理刷收藏音樂列表
private void refreshStoredMusic(Map<String, Object> musicInfo) {
int i = 0;
for (; i < storedMusic.size(); i++) {
Map<String, Object> map = storedMusic.get(i);
String url = (String) map.get("url");
if (url.equals((String) musicInfo.get("url"))) {
Log.d(TAG, "remove index =" + i);
storedMusic.remove(i);
//musicListAdapter.notifyDataSetChanged();
mContext.sendBroadcast(new Intent(ACTION_REFRESH));
return;
}
}
storedMusic.add(musicInfo);
//傳送廣播通知StoredSongFargment更新列表
mContext.sendBroadcast(new Intent(ACTION_REFRESH));
// 重新整理收藏列表有兩種方法：1：重新查詢一次資料庫-呼叫getStoredMusic()，這種效率比較低；2：用上面的方法，直接從storedMusic中刪除或新增
// 這裡用第一種方法
// getStoredMusic();
// 通知介面卡資料發生改變的方法來重新整理列表，最好別用musicListView.setAdapter(adapter)這種方法，該方法會導致焦點重新回到首行
//musicListAdapter.notifyDataSetChanged();
}
public void onAttach(Activity activity) {
super.onAttach(activity);
mCallBack = (CallBack) activity;
}
public void onDestroy() {
super.onDestroy();
}
public interface CallBack {
public void onItemSelected(String url);
public List<Map<String, Object>> getAllMusic();
public List<Map<String, Object>> getStoredMusic();
}
// 執行收藏音樂/取消收藏的非同步任務
private class MyAsyncTask extends AsyncTask<String, Void, Void> {
private ImageView starView;
private Map<String, Object> musicInfo;
// 標記收藏，true表示收藏音樂成功，false表示取消收藏音樂
private boolean storeSuccess;
public MyAsyncTask(ImageView starView, Map<String, Object> musicInfo) {
this.starView = starView;
this.musicInfo = musicInfo;
}
protected void onPreExecute() {
super.onPreExecute();
}
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
protected Void doInBackground(String... params) {
Log.d(TAG, "doInBackground");
Cursor cursor = myHelper.getReadableDatabase().rawQuery(
"select * from stored_music", null);
while (cursor.moveToNext()) {
String title = cursor.getString(1);
String artist = cursor.getString(2);
Log.d(TAG, "title = " + title + " artist = " + artist);
Log.d(TAG,
"musicInfo.title = " + (String) musicInfo.get("title")
+ " musicInfo.artist = "
+ (String) musicInfo.get("artist"));
if (cursor.getString(4).equals((String) musicInfo.get("url"))) {
// 已經收藏的音樂取消收藏並移出收藏音樂表格-stored_music
myHelper.getReadableDatabase()
.execSQL(
"delete from stored_Music where title like ? and artist like ?",
new String[] { title, artist });
storeSuccess = false;
return null;
}
}
// 未收藏的音樂加入到收藏中
myHelper.getReadableDatabase().execSQL(
"insert into stored_music values(null, ?, ?, ?, ?)",
new Object[] { musicInfo.get("title"),
musicInfo.get("artist"), musicInfo.get("duration"),
musicInfo.get("url") });
storeSuccess = true;
return null;
}
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (storeSuccess) {
starView.setImageResource(android.R.drawable.btn_star_big_on);
refreshStoredMusic(musicInfo);
Toast.makeText(mContext, "收藏成功", 100).show();
} else {
starView.setImageResource(android.R.drawable.btn_star_big_off);
refreshStoredMusic(musicInfo);
Toast.makeText(mContext, "取消收藏", 100).show();
}
}
}
}
MusicListFragment主要顯示本地音樂，並提供音樂的收藏和取消收藏操作（非同步任務來完成該操作）。其佈局檔案為：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="@+id/musicList"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
ListView的每個item佈局為：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/RelativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:orientation="horizontal"
android:padding="5dp" >
<ImageView
android:id="@+id/musicTag"
android:layout_width="50dp"
android:layout_height="40dp"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_centerVertical="true"
android:src="@drawable/music" />
<TextView
android:id="@+id/musicTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toRightOf="@id/musicTag"
android:singleLine="true"
android:ellipsize="marquee"
android:marqueeRepeatLimit="marquee_forever"/>
<TextView
android:id="@+id/musicArtist"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/musicTitle"
android:layout_toRightOf="@id/musicTag"
android:text="TextView" />
<ImageView
android:id="@+id/love"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/musicTag"
android:layout_alignParentRight="true"
android:src="@android:drawable/btn_star_big_off"/>
</RelativeLayout>3.StoredSongFragment.java
package com.sprd.easymusic.fragment;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import com.sprd.easymusic.R;
import com.sprd.easymusic.myview.RefreshableListView;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class StoredSongFragment extends Fragment {
private final String TAG = "StoredSongFragment";
private final String ACTION_REFRESH = "action.refreshmusicList";
private List<Map<String, Object>> storedMusic = new ArrayList<>();
private ListView storedMusicList;
private CallBack mCallBack;
private LayoutInflater inflater;
private Context mContext;
public void onAttach(Activity activity) {
super.onAttach(activity);
mCallBack = (CallBack) activity;
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mContext = this.getActivity();
inflater = LayoutInflater.from(mContext);
storedMusic = mCallBack.getStoredMusic();
IntentFilter filter = new IntentFilter();
filter.addAction(ACTION_REFRESH);
mContext.registerReceiver(refreshMusicReceiver, filter);
Log.d(TAG, "onCreate");
}
// StoredSongFragment向外界展示的內容，返回值為view
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater
.inflate(R.layout.storedmusiclist, container, false);
storedMusicList = (ListView) view.findViewById(R.id.storedmusicList);
storedMusicList.setAdapter(musicListAdapter);
storedMusicList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
mCallBack.onItemSelected((String) storedMusic.get(position).get("url"));
TextView title = (TextView) view.findViewWithTag("title");
Toast.makeText(mContext, "title = " + title.getText().toString(),Toast.LENGTH_SHORT).show();
}
});
return view;
}
// 音樂列表介面卡
private BaseAdapter musicListAdapter = new BaseAdapter() {
public int getCount() {
return storedMusic.size();
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return position;
}
public View getView(final int position, View convertView, ViewGroup parent) {
View view = convertView;
Map<String, Object> item = storedMusic.get(position);
if (convertView == null) {
view = inflater.inflate(R.layout.storedmusiclist_item, null);
}
TextView musicTitle = (TextView) view.findViewById(R.id.musicTitle);
musicTitle.setTag("title");
TextView musicArtist = (TextView) view.findViewById(R.id.musicArtist);
musicTitle.setText((String) item.get("title"));
musicArtist.setText((String) item.get("artist"));
return view;
}
};
public void onDestroy() {
if (refreshMusicReceiver != null) mContext.unregisterReceiver(refreshMusicReceiver);
super.onDestroy();
}
public interface CallBack {
public void onItemSelected(String url);
public List<Map<String, Object>> getStoredMusic();
}
//接收來自MusicListFragment的收藏或取消收藏音樂的廣播，並更新收藏列表
private BroadcastReceiver refreshMusicReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(ACTION_REFRESH)) {
musicListAdapter.notifyDataSetChanged();
Toast.makeText(mContext, "重新整理收藏列表成功！", 100).show();
}
}
};
}
StoredSongFragment主要顯示收藏的音樂，也提供播放監聽，其佈局與MusicListragment幾乎一樣（區別在listview的item是否有收藏圖示），因此就不提供了，參考MusicListragment的佈局即可。