Android實現歌曲播放時歌詞同步顯示具體思路

我們需要讀取以上歌詞文件的每一行轉換成成一個個歌詞實體：
代碼如下：

public class LyricObject {
public int begintime; // 開始時間
public int endtime; // 結束時間
public int timeline; // 單句歌詞用時
public String lrc; // 單句歌詞
}

可根據當前播放器的播放進度與每句歌詞的開始時間，得到當前屏幕中央高亮顯示的那句歌詞。在UI線程中另起線程，通過回調函數 onDraw() 每隔100ms重新繪制屏幕，實現歌詞平滑滾動的動畫效果。MainActivity代碼如下：
代碼如下：

import java.io.IOException;
import android.app.Activity;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
public class MainActivity extends Activity {
/** Called when the activity is first created. */
private LyricView lyricView;
private MediaPlayer mediaPlayer;
private Button button;
private SeekBar seekBar;
private String mp3Path;
private int INTERVAL=45;//歌詞每行的間隔
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// this.requestWindowFeature(Window.FEATURE_NO_TITLE);
// getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main);
mp3Path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/LyricSync/1.mp3";
lyricView = (LyricView) findViewById(R.id.mylrc);
mediaPlayer = new MediaPlayer();
// this.requestWindowFeature(Window.FEATURE_NO_TITLE);
ResetMusic(mp3Path);
SerchLrc();
lyricView.SetTextSize();
button = (Button) findViewById(R.id.button);
button.setText("播放");
seekBar = (SeekBar) findViewById(R.id.seekbarmusic);
seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
// TODO Auto-generated method stub
if (fromUser) {
mediaPlayer.seekTo(progress);
lyricView.setOffsetY(220 - lyricView.SelectIndex(progress)
* (lyricView.getSIZEWORD() + INTERVAL-1));
}
}
});
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (mediaPlayer.isPlaying()) {
button.setText("播放");
mediaPlayer.pause();
} else {
button.setText("暫停");
mediaPlayer.start();
lyricView.setOffsetY(220 - lyricView.SelectIndex(mediaPlayer.getCurrentPosition())
* (lyricView.getSIZEWORD() + INTERVAL-1));
}
}
});
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
ResetMusic(mp3Path);
lyricView.SetTextSize();
lyricView.setOffsetY(200);
mediaPlayer.start();
}
});
seekBar.setMax(mediaPlayer.getDuration());
new Thread(new runable()).start();
}
public void SerchLrc() {
String lrc = mp3Path;
lrc = lrc.substring(0, lrc.length() - 4).trim() + ".lrc".trim();
LyricView.read(lrc);
lyricView.SetTextSize();
lyricView.setOffsetY(350);
}
public void ResetMusic(String path) {
mediaPlayer.reset();
try {
mediaPlayer.setDataSource(mp3Path);
mediaPlayer.prepare();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
class runable implements Runnable {
@Override
public void run() {
// TODO Auto-generated method stub
while (true) {
try {
Thread.sleep(100);
if (mediaPlayer.isPlaying()) {
lyricView.setOffsetY(lyricView.getOffsetY() - lyricView.SpeedLrc());
lyricView.SelectIndex(mediaPlayer.getCurrentPosition());
seekBar.setProgress(mediaPlayer.getCurrentPosition());
mHandler.post(mUpdateResults);
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
Handler mHandler = new Handler();
Runnable mUpdateResults = new Runnable() {
public void run() {
lyricView.invalidate(); // 更新視圖
}
};
}

歌詞View的代碼如下：
代碼如下：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Iterator;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
public class LyricView extends View{
private static TreeMap<Integer, LyricObject> lrc_map;
private float mX; //屏幕X軸的中點，此值固定，保持歌詞在X中間顯示
private float offsetY; //歌詞在Y軸上的偏移量，此值會根據歌詞的滾動變小
private static boolean blLrc=false;
private float touchY; //當觸摸歌詞View時，保存為當前觸點的Y軸坐標
private float touchX;
private boolean blScrollView=false;
private int lrcIndex=0; //保存歌詞TreeMap的下標
private int SIZEWORD=0;//顯示歌詞文字的大小值
private int INTERVAL=45;//歌詞每行的間隔
Paint paint=new Paint();//畫筆，用於畫不是高亮的歌詞
Paint paintHL=new Paint(); //畫筆，用於畫高亮的歌詞，即當前唱到這句歌詞
public LyricView(Context context){
super(context);
init();
}
public LyricView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
/* (non-Javadoc)
* @see android.view.View#onDraw(android.graphics.Canvas)
*/
@Override
protected void onDraw(Canvas canvas) {
if(blLrc){
paintHL.setTextSize(SIZEWORD);
paint.setTextSize(SIZEWORD);
LyricObject temp=lrc_map.get(lrcIndex);
canvas.drawText(temp.lrc, mX, offsetY+(SIZEWORD+INTERVAL)*lrcIndex, paintHL);
// 畫當前歌詞之前的歌詞
for(int i=lrcIndex-1;i>=0;i--){
temp=lrc_map.get(i);
if(offsetY+(SIZEWORD+INTERVAL)*i<0){
break;
}
canvas.drawText(temp.lrc, mX, offsetY+(SIZEWORD+INTERVAL)*i, paint);
}
// 畫當前歌詞之後的歌詞
for(int i=lrcIndex+1;i<lrc_map.size();i++){
temp=lrc_map.get(i);
if(offsetY+(SIZEWORD+INTERVAL)*i>600){
break;
}
canvas.drawText(temp.lrc, mX, offsetY+(SIZEWORD+INTERVAL)*i, paint);
}
}
else{
paint.setTextSize(25);
canvas.drawText("找不到歌詞", mX, 310, paint);
}
super.onDraw(canvas);
}
/* (non-Javadoc)
* @see android.view.View#onTouchEvent(android.view.MotionEvent)
*/
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
System.out.println("bllll==="+blScrollView);
float tt=event.getY();
if(!blLrc){
//return super.onTouchEvent(event);
return super.onTouchEvent(event);
}
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
touchX=event.getX();
break;
case MotionEvent.ACTION_MOVE:
touchY=tt-touchY;
offsetY=offsetY+touchY;
break;
case MotionEvent.ACTION_UP:
blScrollView=false;
break;
}
touchY=tt;
return true;
}
public void init(){
lrc_map = new TreeMap<Integer, LyricObject>();
offsetY=320;
paint=new Paint();
paint.setTextAlign(Paint.Align.CENTER);
paint.setColor(Color.GREEN);
paint.setAntiAlias(true);
paint.setDither(true);
paint.setAlpha(180);
paintHL=new Paint();
paintHL.setTextAlign(Paint.Align.CENTER);
paintHL.setColor(Color.RED);
paintHL.setAntiAlias(true);
paintHL.setAlpha(255);
}
/**
* 根據歌詞裡面最長的那句來確定歌詞字體的大小
*/
public void SetTextSize(){
if(!blLrc){
return;
}
int max=lrc_map.get(0).lrc.length();
for(int i=1;i<lrc_map.size();i++){
LyricObject lrcStrLength=lrc_map.get(i);
if(max<lrcStrLength.lrc.length()){
max=lrcStrLength.lrc.length();
}
}
SIZEWORD=320/max;
}
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mX = w * 0.5f;
super.onSizeChanged(w, h, oldw, oldh);
}
/**
* 歌詞滾動的速度
*
* @return 返回歌詞滾動的速度
*/
public Float SpeedLrc(){
float speed=0;
if(offsetY+(SIZEWORD+INTERVAL)*lrcIndex>220){
speed=((offsetY+(SIZEWORD+INTERVAL)*lrcIndex-220)/20);
} else if(offsetY+(SIZEWORD+INTERVAL)*lrcIndex < 120){
Log.i("speed", "speed is too fast!!!");
speed = 0;
}
// if(speed<0.2){
// speed=0.2f;
// }
return speed;
}
/**
* 按當前的歌曲的播放時間，從歌詞裡面獲得那一句
* @param time 當前歌曲的播放時間
* @return 返回當前歌詞的索引值
*/
public int SelectIndex(int time){
if(!blLrc){
return 0;
}
int index=0;
for(int i=0;i<lrc_map.size();i++){
LyricObject temp=lrc_map.get(i);
if(temp.begintime<time){
++index;
}
}
lrcIndex=index-1;
if(lrcIndex<0){
lrcIndex=0;
}
return lrcIndex;
}
/**
* 讀取歌詞文件
* @param file 歌詞的路徑
*
*/
public static void read(String file) {
TreeMap<Integer, LyricObject> lrc_read =new TreeMap<Integer, LyricObject>();
String data = "";
try {
File saveFile=new File(file);
// System.out.println("是否有歌詞文件"+saveFile.isFile());
if(!saveFile.isFile()){
blLrc=false;
return;
}
blLrc=true;
//System.out.println("bllrc==="+blLrc);
FileInputStream stream = new FileInputStream(saveFile);// context.openFileInput(file);
BufferedReader br = new BufferedReader(new InputStreamReader(stream,"GB2312"));
int i = 0;
Pattern pattern = Pattern.compile("\\d{2}");
while ((data = br.readLine()) != null) {
// System.out.println("++++++++++++>>"+data);
data = data.replace("[","");//將前面的替換成後面的
data = data.replace("]","@");
String splitdata[] =data.split("@");//分隔
if(data.endsWith("@")){
for(int k=0;k<splitdata.length;k++){
String str=splitdata[k];
str = str.replace(":",".");
str = str.replace(".","@");
String timedata[] =str.split("@");
Matcher matcher = pattern.matcher(timedata[0]);
if(timedata.length==3 && matcher.matches()){
int m = Integer.parseInt(timedata[0]); //分
int s = Integer.parseInt(timedata[1]); //秒
int ms = Integer.parseInt(timedata[2]); //毫秒
int currTime = (m*60+s)*1000+ms*10;
LyricObject item1= new LyricObject();
item1.begintime = currTime;
item1.lrc = "";
lrc_read.put(currTime,item1);
}
}
}
else{
String lrcContenet = splitdata[splitdata.length-1];
for (int j=0;j<splitdata.length-1;j++)
{
String tmpstr = splitdata[j];
tmpstr = tmpstr.replace(":",".");
tmpstr = tmpstr.replace(".","@");
String timedata[] =tmpstr.split("@");
Matcher matcher = pattern.matcher(timedata[0]);
if(timedata.length==3 && matcher.matches()){
int m = Integer.parseInt(timedata[0]); //分
int s = Integer.parseInt(timedata[1]); //秒
int ms = Integer.parseInt(timedata[2]); //毫秒
int currTime = (m*60+s)*1000+ms*10;
LyricObject item1= new LyricObject();
item1.begintime = currTime;
item1.lrc = lrcContenet;
lrc_read.put(currTime,item1);// 將currTime當標簽 item1當數據 插入TreeMap裡
i++;
}
}
}
}
stream.close();
}
catch (FileNotFoundException e) {
}
catch (IOException e) {
}
/*
* 遍歷hashmap 計算每句歌詞所需要的時間
*/
lrc_map.clear();
data ="";
Iterator<Integer> iterator = lrc_read.keySet().iterator();
LyricObject oldval = null;
int i =0;
while(iterator.hasNext()) {
Object ob =iterator.next();
LyricObject val = (LyricObject)lrc_read.get(ob);
if (oldval==null)
oldval = val;
else
{
LyricObject item1= new LyricObject();
item1 = oldval;
item1.timeline = val.begintime-oldval.begintime;
lrc_map.put(new Integer(i), item1);
i++;
oldval = val;
}
if (!iterator.hasNext()) {
lrc_map.put(new Integer(i), val);
}
}
}
/**
* @return the blLrc
*/
public static boolean isBlLrc() {
return blLrc;
}
/**
* @return the offsetY
*/
public float getOffsetY() {
return offsetY;
}
/**
* @param offsetY the offsetY to set
*/
public void setOffsetY(float offsetY) {
this.offsetY = offsetY;
}
/**
* @return 返回歌詞文字的大小
*/
public int getSIZEWORD() {
return SIZEWORD;
}
/**
* 設置歌詞文字的大小
* @param sIZEWORD the sIZEWORD to set
*/
public void setSIZEWORD(int sIZEWORD) {
SIZEWORD = sIZEWORD;
}
}

xml布局文件如下：
代碼如下：

<SPAN ><STRONG><?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFFFF" >
<com.music.lyricsync.LyricView
android:id="@+id/mylrc"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginBottom="50dip"
android:layout_marginTop="50dip" />
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="horizontal" >
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<SeekBar
android:id="@+id/seekbarmusic"
android:layout_width="205px"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginBottom="5px"
android:progress="0" />
</LinearLayout>
</RelativeLayout> </STRONG></SPAN>