Android 实现旋转木马的音乐效果

一、百度在线音乐旋转木马效果

就上面那个，当音乐在播放的时候，那个光碟*在转，就想旋转木马一般。感觉好好玩啊。
碰巧想起前阵子做音乐播放器，哎，那这个也可以做在手机的音乐播放器上，这样就代替了进度条了。
一想到，就兴奋，于是，首先画圆形，然后放置背景图片，然后使用动画旋转。当音乐播放时，同时
开始播放圆形图片的动画，当音乐暂停时，暂停旋转；当音乐停止播放时，就停止动画，图片回到原点。

二、效果

三、实现代码

（1）mainactivity  

<span style="font-size:18px;">public class mainactivity extends activity {
  mediaplayer m1;
  imageview infooperatingiv;
 
  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);
    infooperatingiv = (imageview) findviewbyid(r.id.infooperating);
 
    button play = (button) findviewbyid(r.id.play);
    button stop = (button) findviewbyid(r.id.stop);
 
    play.setonclicklistener(new onclicklistener() {
      @override
      public void onclick(view v) {
        playmusic();
      }
    });
 
    stop.setonclicklistener(new onclicklistener() {
      @override
      public void onclick(view v) {
        stopmusic();
      }
    });
 
  }
 
  private void playmusic() {
    m1 = mediaplayer.create(this, r.raw.quiet);
    m1.start();
 
    animation operatinganim = animationutils.loadanimation(this, r.anim.tip);
    linearinterpolator lin = new linearinterpolator();
    operatinganim.setinterpolator(lin);
    if (operatinganim != null) {
      infooperatingiv.startanimation(operatinganim);
    }
 
    m1.setoncompletionlistener(new oncompletionlistener() {
      @override
      public void oncompletion(mediaplayer mp) {
        mp.stop();
        infooperatingiv.clearanimation();
      }
    });
  }
 
  private void stopmusic() {
    m1.stop();
    infooperatingiv.clearanimation();
  }
 
}</span><span style="font-size: 16pt;">
</span>

（2）画圆的控件，这部分代码参考了网友的。

  <span style="font-size:18px;">public class roundimageview extends imageview {
  private int mborderthickness = 0;
  private context mcontext;
  private int defaultcolor = 0xffffffff;
  // 如果只有其中一个有值，则只画一个圆形边框
  private int mborderoutsidecolor = 0;
  private int mborderinsidecolor = 0;
  // 控件默认长、宽
  private int defaultwidth = 0;
  private int defaultheight = 0;
 
  public roundimageview(context context) {
    super(context);
    mcontext = context;
  }
 
  public roundimageview(context context, attributeset attrs) {
    super(context, attrs);
    mcontext = context;
    setcustomattributes(attrs);
  }
 
  public roundimageview(context context, attributeset attrs, int defstyle) {
    super(context, attrs, defstyle);
    mcontext = context;
    setcustomattributes(attrs);
  }
 
  private void setcustomattributes(attributeset attrs) {
    typedarray a = mcontext.obtainstyledattributes(attrs, r.styleable.roundedimageview);
    mborderthickness = a.getdimensionpixelsize(r.styleable.roundedimageview_border_thickness, 0);
    mborderoutsidecolor = a.getcolor(r.styleable.roundedimageview_border_outside_color, defaultcolor);
    mborderinsidecolor = a.getcolor(r.styleable.roundedimageview_border_inside_color, defaultcolor);
  }
 
  @override
  protected void ondraw(canvas canvas) {
    drawable drawable = getdrawable();
    if (drawable == null) {
      return;
    }
 
    if (getwidth() == 0 || getheight() == 0) {
      return;
    }
    this.measure(0, 0);
    if (drawable.getclass() == ninepatchdrawable.class)
      return;
    bitmap b = ((bitmapdrawable) drawable).getbitmap();
    bitmap bitmap = b.copy(bitmap.config.argb_8888, true);
    if (defaultwidth == 0) {
      defaultwidth = getwidth();
 
    }
    if (defaultheight == 0) {
      defaultheight = getheight();
    }
    // 保证重新读取图片后不会因为图片大小而改变控件宽、高的大小（针对宽、高为wrap_content布局的imageview，但会导致margin无效）
    // if (defaultwidth != 0 && defaultheight != 0) {
    // linearlayout.layoutparams params = new linearlayout.layoutparams(
    // defaultwidth, defaultheight);
    // setlayoutparams(params);
    // }
    int radius = 0;
    if (mborderinsidecolor != defaultcolor && mborderoutsidecolor != defaultcolor) {// 定义画两个边框，分别为外圆边框和内圆边框
      radius = (defaultwidth < defaultheight ? defaultwidth : defaultheight) / 2 - 2 * mborderthickness;
      // 画内圆
      drawcircleborder(canvas, radius + mborderthickness / 2, mborderinsidecolor);
      // 画外圆
      drawcircleborder(canvas, radius + mborderthickness + mborderthickness / 2, mborderoutsidecolor);
    } else if (mborderinsidecolor != defaultcolor && mborderoutsidecolor == defaultcolor) {// 定义画一个边框
      radius = (defaultwidth < defaultheight ? defaultwidth : defaultheight) / 2 - mborderthickness;
      drawcircleborder(canvas, radius + mborderthickness / 2, mborderinsidecolor);
    } else if (mborderinsidecolor == defaultcolor && mborderoutsidecolor != defaultcolor) {// 定义画一个边框
      radius = (defaultwidth < defaultheight ? defaultwidth : defaultheight) / 2 - mborderthickness;
      drawcircleborder(canvas, radius + mborderthickness / 2, mborderoutsidecolor);
    } else {// 没有边框
      radius = (defaultwidth < defaultheight ? defaultwidth : defaultheight) / 2;
    }
    bitmap roundbitmap = getcroppedroundbitmap(bitmap, radius);
    canvas.drawbitmap(roundbitmap, defaultwidth / 2 - radius, defaultheight / 2 - radius, null);
  }
 
  /**
   * 获取裁剪后的圆形图片
   *
   * @param radius
   *      半径
   */
  public bitmap getcroppedroundbitmap(bitmap bmp, int radius) {
    bitmap scaledsrcbmp;
    int diameter = radius * 2;
 
    // 为了防止宽高不相等，造成圆形图片变形，因此截取长方形中处于中间位置最大的正方形图片
    int bmpwidth = bmp.getwidth();
    int bmpheight = bmp.getheight();
    int squarewidth = 0, squareheight = 0;
    int x = 0, y = 0;
    bitmap squarebitmap;
    if (bmpheight > bmpwidth) {// 高大于宽
      squarewidth = squareheight = bmpwidth;
      x = 0;
      y = (bmpheight - bmpwidth) / 2;
      // 截取正方形图片
      squarebitmap = bitmap.createbitmap(bmp, x, y, squarewidth, squareheight);
    } else if (bmpheight < bmpwidth) {// 宽大于高
      squarewidth = squareheight = bmpheight;
      x = (bmpwidth - bmpheight) / 2;
      y = 0;
      squarebitmap = bitmap.createbitmap(bmp, x, y, squarewidth, squareheight);
    } else {
      squarebitmap = bmp;
    }
 
    if (squarebitmap.getwidth() != diameter || squarebitmap.getheight() != diameter) {
      scaledsrcbmp = bitmap.createscaledbitmap(squarebitmap, diameter, diameter, true);
 
    } else {
      scaledsrcbmp = squarebitmap;
    }
    bitmap output = bitmap.createbitmap(scaledsrcbmp.getwidth(), scaledsrcbmp.getheight(), config.argb_8888);
    canvas canvas = new canvas(output);
 
    paint paint = new paint();
    rect rect = new rect(0, 0, scaledsrcbmp.getwidth(), scaledsrcbmp.getheight());
 
    paint.setantialias(true);
    paint.setfilterbitmap(true);
    paint.setdither(true);
    canvas.drawargb(0, 0, 0, 0);
    canvas.drawcircle(scaledsrcbmp.getwidth() / 2, scaledsrcbmp.getheight() / 2, scaledsrcbmp.getwidth() / 2, paint);
    paint.setxfermode(new porterduffxfermode(mode.src_in));
    canvas.drawbitmap(scaledsrcbmp, rect, rect, paint);
     
    bmp = null;
    squarebitmap = null;
    scaledsrcbmp = null;
    return output;
  }
 
  /**
   * 边缘画圆
   */
  private void drawcircleborder(canvas canvas, int radius, int color) {
    paint paint = new paint();
    /* 去锯齿 */
    paint.setantialias(true);
    paint.setfilterbitmap(true);
    paint.setdither(true);
    paint.setcolor(color);
    /* 设置paint的　style　为stroke：空心 */
    paint.setstyle(paint.style.stroke);
    /* 设置paint的外框宽度 */
    paint.setstrokewidth(mborderthickness);
    canvas.drawcircle(defaultwidth / 2, defaultheight / 2, radius, paint);
  }
 
}</span><span style="font-size: 16pt;">
</span>

以上就是android 实现旋转木马的音乐效果,有需要的朋友可以参考下。