Android自定义View实现多片叶子旋转滑动（五）

上一篇《android 自定义view(四) 叶子飘动+旋转效果》实现了单片叶子的滑动及旋转，下面实现多片叶子的滑动旋转功能

实现思路比较简单，就是添加一个叶子leaf类，储存每片叶子的信息，

然后随机产生叶子的坐标及旋转角度，最后实时获取每片叶子信息，添加到画布中

1、leaf.java 叶子类

 private class leaf {
  // 叶子的坐标
  float x, y;
  // 旋转角度
  int rotateangle;
  // 起始时间(ms)
  long starttime;
 }

2、初始化每片叶子的信息，然后保存到list中

 //使叶子初始时间有间隔
 int addtime;
 private leaf getleaf() {
  random random = new random();
  leaf leaf = new leaf();
  //随机初始化叶子初始角度
  leaf.rotateangle = random.nextint(360);
  //随机初始化叶子启动时间
  addtime += random.nextint((int) (cycletime));
  leaf.starttime = system.currenttimemillis() + cycletime + addtime;
  return leaf;
 }
 private list<leaf> getleafs(int leafsize) {
  list<leaf> list = new linkedlist<leaf>();
  for (int i=0; i<leafsize; i++) {
   list.add(getleaf());
  }
  return list;
 }

3、接下去就是改写getlocation()及getrotate()方法，使其返回每片叶子的坐标及旋转角度

 //获取每片叶子在xy轴上的滑动值
 private void getlocation(leaf leaf) {
  float betweentime = leaf.starttime - system.currenttimemillis();
  //周期结束再加一个cycletime
  if(betweentime < 0) {
   leaf.starttime = system.currenttimemillis() + cycletime + new random().nextint((int) (cycletime));
   betweentime = cycletime;
  }
  //通过时间差计算出叶子的坐标
  float fraction = (float) betweentime / cycletime;
  float x = (int)(width * fraction);
  leaf.x = x;
  float w = (float) ((float) 2 * math.pi / width);
  int y = (int) (18 * math.sin(w * x)) + (height-mleafheight)/2;
  leaf.y = y;

 }

 //获取每片叶子的旋转角度
 private void getrotate(leaf leaf) {
  float scale = ((leaf.starttime - system.currenttimemillis())%cycletime)/ (float)cycletime;
  int rotate = (int)(scale * 360);
  leaf.rotateangle = rotate;
 }

4、在ondraw()方法中，画出每片叶子

 @override
 protected void ondraw(canvas canvas) {
  super.ondraw(canvas);
  //画叶子
  int size = leaflist.size();
  for (int i=0; i<size; i++) {
   leaf leaf = leaflist.get(i);
   //获取叶子坐标
   getlocation(leaf);
   //获取叶子旋转角度
   getrotate(leaf);
   canvas.save();
   matrix matrix = new matrix();
   //设置滑动
   matrix.posttranslate(leaf.x, leaf.y);
   //设置旋转
   matrix.postrotate(leaf.rotateangle, leaf.x + mleafwidth / 2, leaf.y + mleafheight / 2);
   //添加叶子到画布
   canvas.drawbitmap(mleafbitmap, matrix, new paint());
   canvas.restore();
  }
  //调用ondraw()重复滑动
  postinvalidate();
 }

完整代码：

public class leafview extends view {
 private string tag = "--------leafview";
 private resources mresources;
 //背景图、叶子
 private bitmap mleafbitmap, bgbitmap;
 //整个控件的宽度和高度
 private int width, height;
 private paint bgpaint;
 private rectf bgrect;
 private rect bgdestrect;
 //存放叶子lsit
 private list<leaf> leaflist;
 //叶子的宽和高
 private int mleafwidth, mleafheight;
 //叶子滑动一周的时间5秒
 private final static long cycletime = 5000;
 //叶子数量
 private final static int leafnumber = 5;
 public leafview(context context, attributeset attrs) {
  super(context, attrs);
  mresources = getresources();
  mleafbitmap = ((bitmapdrawable) mresources.getdrawable(r.drawable.leaf, null)).getbitmap();
  mleafwidth = mleafbitmap.getwidth();
  mleafheight = mleafbitmap.getheight()

  bgbitmap = ((bitmapdrawable) mresources.getdrawable(r.drawable.leaf_kuang, null)).getbitmap();
  bgpaint = new paint();
  bgpaint.setcolor(mresources.getcolor(r.color.bg_color));
  //获取所有叶子的信息，放入list
  leaflist = getleafs(leafnumber);
 }

 @override
 protected void onsizechanged(int w, int h, int oldw, int oldh) {
  super.onsizechanged(w, h, oldw, oldh);
  width = w;
  height = h;
  bgdestrect = new rect(0, 0 , width, height);
 }

 @override
 protected void ondraw(canvas canvas) {
  super.ondraw(canvas);
  bgrect = new rectf(0, 0 , width, height);
  //画背景颜色到画布
  canvas.drawrect(bgrect, bgpaint);
  //画背景图片到画布
  canvas.drawbitmap(bgbitmap, null, bgdestrect, null);

  //画叶子
  int size = leaflist.size();
  for (int i=0; i<size; i++) {
   leaf leaf = leaflist.get(i);
   //获取叶子坐标
   getlocation(leaf);
   //获取叶子旋转角度
   getrotate(leaf);
   canvas.save();
   matrix matrix = new matrix();
   //设置滑动
   matrix.posttranslate(leaf.x, leaf.y);
   //设置旋转
   matrix.postrotate(leaf.rotateangle, leaf.x + mleafwidth / 2, leaf.y + mleafheight / 2);
   //添加叶子到画布
   canvas.drawbitmap(mleafbitmap, matrix, new paint());
   canvas.restore();
  }
  //调用ondraw()重复滑动
  postinvalidate();
 }

 //获取每片叶子在xy轴上的滑动值
 private void getlocation(leaf leaf) {
  float betweentime = leaf.starttime - system.currenttimemillis();
  //周期结束再加一个cycletime
  if(betweentime < 0) {
   leaf.starttime = system.currenttimemillis() + cycletime + new random().nextint((int) (cycletime));
   betweentime = cycletime;
  }
  //通过时间差计算出叶子的坐标
  float fraction = (float) betweentime / cycletime;
  float x = (int)(width * fraction);
  leaf.x = x;
  float w = (float) ((float) 2 * math.pi / width);
  int y = (int) (18 * math.sin(w * x)) + (height-mleafheight)/2;
  leaf.y = y;
 }

 //获取每片叶子的旋转角度
 private void getrotate(leaf leaf) {
  float scale = ((leaf.starttime - system.currenttimemillis())%cycletime)/ (float)cycletime;
  int rotate = (int)(scale * 360);
  leaf.rotateangle = rotate;
 }

 private class leaf {
  // 叶子的坐标
  float x, y;
  // 旋转角度
  int rotateangle;
  // 起始时间(ms)
  long starttime;
 }

 private list<leaf> getleafs(int leafsize) {
  list<leaf> list = new linkedlist<leaf>();
  for (int i=0; i<leafsize; i++) {
   list.add(getleaf());
  }
  return list;
 }

 //使叶子初始时间有间隔
 int addtime;
 private leaf getleaf() {
  random random = new random();
  leaf leaf = new leaf();
  leaf.rotateangle = random.nextint(360);
  addtime += random.nextint((int) (cycletime));
  leaf.starttime = system.currenttimemillis() + cycletime + addtime;
  return leaf;
 }
}

这里还有很多瑕疵，比如叶子的滑动范围覆盖了边框等等

需要图片等信息的可以从下面的github地址下载，不过原文比较复杂

参考 https://github.com/ajian-studio/galeafloading

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。