Android自定义控件之自定义View(三)——自定义水波纹

来源：互联网发布：跑团用软件编辑：程序博客网时间：2024/05/17 05:06

转载请注明出处：http://blog.csdn.net/xiaohao0724/article/details/54572605

上一篇我们实现了点击屏幕以点击的这个点为圆心画圆并放大，现在我们对上篇进一步加深自定义水波纹效果。

效果图如下:

1、定义一个自定义View和水波纹类，并在构造方法里面初始化水波纹类集合

public class RingWaveView extends View {public RingWaveView(Context context, AttributeSet attrs) {super(context, attrs);ringWaveViewList = new ArrayList<RingWaveView.Wave>();}/** * 定义一个波浪 */private class Wave {int cx; // 圆心横坐标int cy; // 圆心纵坐标Paint paint; // 画笔int radius; // 半径}}

2、重写onTouchEvent方法确定水波纹的圆心和半径

@Overridepublic boolean onTouchEvent(MotionEvent event) {super.onTouchEvent(event);switch (event.getAction()) {case MotionEvent.ACTION_DOWN:case MotionEvent.ACTION_MOVE:int x = (int) event.getX();int y = (int) event.getY();addPoint(x, y);break;default:break;}return true;}/** * 添加新的波浪中心点 *  * @param x * @param y */private void addPoint(int x, int y) {if (ringWaveViewList.size() == 0) {addPoint2List(x, y);/* * 第一次启动动画 */isRunning = true;handler.sendEmptyMessage(0);} else { Wave wave = ringWaveViewList.get(ringWaveViewList.size() - 1);//判断当手指滑动与上一个圆环相差20px时再添加新的圆环if (Math.abs(wave.cx - x) > DIS_SOLP|| Math.abs(wave.cy - y) > DIS_SOLP) {addPoint2List(x, y);}};}/** * 添加新的波浪 *  * @param x * @param y */private void addPoint2List(int x, int y) {Wave wave = new Wave();wave.cx = x;wave.cy = y;Paint paint = new Paint();paint.setColor(colors[(int) (Math.random() * 5)]);paint.setAntiAlias(true);paint.setStyle(Style.STROKE);wave.paint = paint;ringWaveViewList.add(wave);}

3、重写onDraw方法绘制水波纹

@Overrideprotected void onDraw(Canvas canvas) {for (int i = 0; i < ringWaveViewList.size(); i++) {Wave wave = ringWaveViewList.get(i);canvas.drawCircle(wave.cx, wave.cy, wave.radius, wave.paint);}}

4、根据手机触摸移动通过Handler发消息刷新数据重绘水波纹

private Handler handler = new Handler() {public void handleMessage(android.os.Message msg) {// 刷新数据flushData();// 刷新页面invalidate();// 循环动画if (isRunning) {handler.sendEmptyMessageDelayed(0, 50);}};};/** * 刷新数据 */private void flushData() {for (int i = 0; i < ringWaveViewList.size(); i++) {Wave wave = ringWaveViewList.get(i);// 如果透明度为 0 从集合中删除int alpha = wave.paint.getAlpha();if (alpha == 0) {ringWaveViewList.remove(i); // 删除i 以后，i的值应该再减1i--;// 否则会漏掉一个对象，不过，在此处影响不大，效果上看不出来。continue;}alpha -= 5;if (alpha < 5) {alpha = 0;}// 降低透明度wave.paint.setAlpha(alpha);// 扩大半径wave.radius = wave.radius + 4;// 设置半径厚度wave.paint.setStrokeWidth(wave.radius / 4);}/* * 如果集合被清空，就停止刷新动画 */if (ringWaveViewList.size() == 0) {isRunning = false;}}

OK，大功告成，有没有很炫的赶脚

点击下载源码

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