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1. 音乐播放,音乐播放，音乐播放放入服务中,那么App 退入后台音乐也可以播放
2. 歌词显示控件TextView自定义：
使用控件TextView, 为什么不用Listview,歌词不可以手动滚动
如何实现：
2.1 根据当前播放进度找到对应歌词
2.2. 绘制当前
2.2. 往前计算坐标，绘制之前歌词
2.3. 往后计算坐标，绘制之后歌词
int currentPosition = musicPlayerService.getCurrentPosition();
=========歌词格式=============================================
[00:01.79]心碎了无痕
[00:02.94]作词:MICHEAL 作曲:吴旭文
[00:04.16]演唱：张学友
[00:05.41]
[00:26.62]闭上你的眼 我的爱人
[00:32.22]吻住你吻住疑问
[00:37.71]你的心已变像落叶飞远
[00:43.65]我宁愿瞎了眼看不见
[00:47.75]
[00:48.95]求求你千千万万不要走
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每句歌词播放时间都有，获取当前 currentPosition 播放时间，然后去歌曲中 找 对应歌词
布局xml文件：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.itheima.videoplay.LyricActivity">
<View
android:id="@+id/header"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#bfa"></View>
<Button
android:id="@+id/footer"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#bfc"
android:layout_alignParentBottom="true"
android:text="下一句"
android:gravity="center"
android:onClick="nextSentence"
></Button>
<com.itheima.videoplay.words.MyLyricView1
android:id="@+id/mylyriceview1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/header"
android:layout_above="@+id/footer"
android:background="#000"
></com.itheima.videoplay.words.MyLyricView1>
</RelativeLayout>
Java代码：MyLyricView1
package com.itheima.videoplay.words;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.widget.TextView;
import java.util.ArrayList;
/**
* Created by Administrator on 2018/11/11.
*/
public class MyLyricView1 extends TextView {
// 歌词类
private ArrayList<Lyric> lyrics;
private Paint paint;
private Paint whitepaint;
private int width;
private int height;
//歌词列表中的索引，是第几句歌词
private int index=6;
// 每行的高
private float textHeight ;
// 当前歌词内容
private String content;
// 时间戳
private long timePoint;
// 休眠时间或者高亮显示的时间
private long sleepTime;
// 当前播放位置
private float currentPositon;
public ArrayList<Lyric> getLyrics() {
return lyrics;
}
public void setLyrics(ArrayList<Lyric> lyrics) {
this.lyrics = lyrics;
}
public MyLyricView1(Context context) {
this(context,null);
}
public MyLyricView1(Context context, @Nullable AttributeSet attrs) {
this(context, attrs,0);
}
public MyLyricView1(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initView(context);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width = w;
height = h;
}
public void setshowNextLyric(int currentPosition) {
// this.currentPositon= currentPosition;
// if(lyrics == null || lyrics.size() == 0 ){
// return;
// }
// for (int i = 1; i < lyrics.size(); i++) {
//
// if(currentPosition < lyrics.get(i).getTimePoint()){
//
// int tempIndex = i - 1;
//
// if(currentPosition >= lyrics.get(tempIndex).getTimePoint()){
// //当前正在播放的哪句歌词
// index = tempIndex;
// sleepTime = lyrics.get(index).getSleepTime();
// timePoint = lyrics.get(index).getTimePoint();
// }
//
// }
// }
currentPosition++;
this.index=currentPosition;
//重新绘制
invalidate();//在主线程中
//子线程
// postInvalidate();
}
private void initView(Context context) {
textHeight = DensityUtil.dip2px(context,18);//对应的像数
//创建画笔 画中间内容
paint = new Paint();
paint.setColor(Color.GREEN);
paint.setTextSize(DensityUtil.dip2px(context,16));
paint.setAntiAlias(true);
//设置居中对齐，画出来的内容会在View中居中
paint.setTextAlign(Paint.Align.CENTER);
// 画上下内容
whitepaint = new Paint();
whitepaint.setColor(Color.WHITE);
whitepaint.setTextSize(DensityUtil.dip2px(context,16));
whitepaint.setAntiAlias(true);
//设置居中对齐
whitepaint.setTextAlign(Paint.Align.CENTER);
// 测试代码，假的歌词
lyrics = new ArrayList<>();
Lyric lyric = new Lyric();
for (int i = 0; i < 1000; i++) {
lyric.setTimePoint(1000 * i);
lyric.setSleepTime(1500 + i);
lyric.setContent(i + "aaaaaaaaaaaaaaa" + i);
//把歌词添加到集合中
lyrics.add(lyric);
lyric = new Lyric();
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(lyrics != null && lyrics.size() >0 ){
//1. 绘制歌词:绘制当前句
String currentText = lyrics.get(index).getContent();
canvas.drawText(currentText, width / 2, height / 2, paint);
// 2. 绘制前面部分
float tempY = height / 2;//Y轴的中间坐标
for (int i = index - 1; i >= 0; i--) {
//每一句歌词
String preContent = lyrics.get(i).getContent();
tempY = tempY - textHeight;
if (tempY < 0) {
break;
}
/****
* paint.setTextAlign(Paint.Align.CENTER); 设置以后
* 绘制文本 坐标基于 context 的中心点
*/
canvas.drawText(preContent, width / 2, tempY, whitepaint);
}
// 3. 绘制后面部分
tempY = height / 2;//Y轴的中间坐标
for (int i = index + 1; i < lyrics.size(); i++) {
//每一句歌词
String nextContent = lyrics.get(i).getContent();
tempY = tempY + textHeight;
if (tempY > height) {
break;
}
canvas.drawText(nextContent, width / 2, tempY, whitepaint);
}
}else{
//没有歌词
canvas.drawText("没有歌词", width / 2, height / 2, paint);
}
}
}
使用：
public class LyricActivity extends Activity {
MyLyricView1 myLyricView1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lyric);
myLyricView1 = findViewById(R.id.mylyriceview1);
}
int index=6;
public void nextSentence(View veiw){
myLyricView1.setshowNextLyric(index++);
}
}效果图：
