Android 实现圆圈扩散水波动画效果两种方法

两种方式实现类似水波扩散效果，先上图为敬

自定义view实现
动画实现

自定义view实现

思路分析：通过canvas画圆，每次改变圆半径和透明度，当半径达到一定程度，再次从中心开始绘圆，达到不同层级的效果，通过不断绘制达到view扩散效果

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									private Paint centerPaint; //中心圆paint

									private int radius = 100; //中心圆半径

									private Paint spreadPaint; //扩散圆paint

									private float centerX;//圆心x

									private float centerY;//圆心y

									private int distance = 5; //每次圆递增间距

									private int maxRadius = 80; //最大圆半径

									private int delayMilliseconds = 33;//扩散延迟间隔，越大扩散越慢

									private List<Integer> spreadRadius = new ArrayList<>();//扩散圆层级数，元素为扩散的距离

									private List<Integer> alphas = new ArrayList<>();//对应每层圆的透明度

style文件里自定义属性

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									<declare-styleable name="SpreadView">

									  <!--中心圆颜色-->

									  <attr name="spread_center_color" format="color" />

									  <!--中心圆半径-->

									  <attr name="spread_radius" format="integer" />

									  <!--扩散圆颜色-->

									  <attr name="spread_spread_color" format="color" />

									  <!--扩散间距-->

									  <attr name="spread_distance" format="integer" />

									  <!--扩散最大半径-->

									  <attr name="spread_max_radius" format="integer" />

									  <!--扩散延迟间隔-->

									  <attr name="spread_delay_milliseconds" format="integer" />

									</declare-styleable>

初始化

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									public SpreadView(Context context) {

									  this(context, null, 0);

									}

									public SpreadView(Context context, @Nullable AttributeSet attrs) {

									  this(context, attrs, 0);

									}

									public SpreadView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {

									  super(context, attrs, defStyleAttr);

									  TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SpreadView, defStyleAttr, 0);

									  radius = a.getInt(R.styleable.SpreadView_spread_radius, radius);

									  maxRadius = a.getInt(R.styleable.SpreadView_spread_max_radius, maxRadius);

									  int centerColor = a.getColor(R.styleable.SpreadView_spread_center_color, ContextCompat.getColor(context, R.color.colorAccent));

									  int spreadColor = a.getColor(R.styleable.SpreadView_spread_spread_color, ContextCompat.getColor(context, R.color.colorAccent));

									  distance = a.getInt(R.styleable.SpreadView_spread_distance, distance);

									  a.recycle();

									  centerPaint = new Paint();

									  centerPaint.setColor(centerColor);

									  centerPaint.setAntiAlias(true);

									  //最开始不透明且扩散距离为0

									  alphas.add(255);

									  spreadRadius.add(0);

									  spreadPaint = new Paint();

									  spreadPaint.setAntiAlias(true);

									  spreadPaint.setAlpha(255);

									  spreadPaint.setColor(spreadColor);

									}

确定圆心位置

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									@Override

									protected void onSizeChanged(int w, int h, int oldw, int oldh) {

									  super.onSizeChanged(w, h, oldw, oldh);

									  //圆心位置

									  centerX = w / 2;

									  centerY = h / 2;

									}

自定义view的绘制

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									@Override

									protected void onDraw(Canvas canvas) {

									  super.onDraw(canvas);

									  for (int i = 0; i < spreadRadius.size(); i++) {

									    int alpha = alphas.get(i);

									    spreadPaint.setAlpha(alpha);

									    int width = spreadRadius.get(i);

									    //绘制扩散的圆

									    canvas.drawCircle(centerX, centerY, radius + width, spreadPaint);

									    //每次扩散圆半径递增，圆透明度递减

									    if (alpha > 0 && width < 300) {

									      alpha = alpha - distance > 0 ? alpha - distance : 1;

									      alphas.set(i, alpha);

									      spreadRadius.set(i, width + distance);

									    }

									  }

									  //当最外层扩散圆半径达到最大半径时添加新扩散圆

									  if (spreadRadius.get(spreadRadius.size() - 1) > maxRadius) {

									    spreadRadius.add(0);

									    alphas.add(255);

									  }

									  //超过8个扩散圆，删除最先绘制的圆，即最外层的圆

									  if (spreadRadius.size() >= 8) {

									    alphas.remove(0);

									    spreadRadius.remove(0);

									  }

									  //中间的圆

									  canvas.drawCircle(centerX, centerY, radius, centerPaint);

									  //TODO 可以在中间圆绘制文字或者图片

									  //延迟更新，达到扩散视觉差效果

									  postInvalidateDelayed(delayMilliseconds);

									}

xml样式

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									<com.airsaid.diffuseview.widget.SpreadView

									  android:id="@+id/spreadView"

									  android:layout_width="match_parent"

									  android:layout_height="wrap_content"

									  app:spread_center_color="@color/colorAccent"

									  app:spread_delay_milliseconds="35"

									  app:spread_distance="5"

									  app:spread_max_radius="90"

									  app:spread_radius="100"

									  app:spread_spread_color="@color/colorAccent" />

效果图

Android 实现圆圈扩散水波动画效果两种方法

中心圆处可以自定义写文字，画图片等等...

动画实现

思路分析：通过动画实现，imageView不停做动画缩放+渐变

最中心的imageView保持不变

中间一层imageView从原始放大到1.4倍，同时从不透明变为半透明

最外层的imageView从1.4倍放大到1.8倍，同时从半透明变为全透明

利用shape画一个圆，作为动画基础视图

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									<?xml version="1.0" encoding="utf-8"?>

									<shape xmlns:android="http://schemas.android.com/apk/res/android">

									  <corners android:radius="65dp"/>

									  <solid android:color="@color/colorAccent"/>

									</shape>

布局视图

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									<FrameLayout

									  android:layout_width="match_parent"

									  android:layout_height="match_parent">

									  <!--中心imageView-->

									  <ImageView

									    android:id="@+id/iv_wave"

									    android:layout_width="130dp"

									    android:layout_height="130dp"

									    android:layout_gravity="center"

									    android:background="@drawable/shape_circle" />

									  <!--中间的imageView-->

									  <ImageView

									    android:id="@+id/iv_wave_1"

									    android:layout_width="130dp"

									    android:layout_height="130dp"

									    android:layout_gravity="center"

									    android:background="@drawable/shape_circle" />

									  <!--最外层imageView-->

									  <ImageView

									    android:id="@+id/iv_wave_2"

									    android:layout_width="130dp"

									    android:layout_height="130dp"

									    android:layout_gravity="center"

									    android:background="@drawable/shape_circle" />

									</FrameLayout>

中间imageView的动画

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									private void setAnim1() {

									  AnimationSet as = new AnimationSet(true);

									  //缩放动画，以中心从原始放大到1.4倍

									  ScaleAnimation scaleAnimation = new ScaleAnimation(1.0f, 1.4f, 1.0f, 1.4f,

									      ScaleAnimation.RELATIVE_TO_SELF, 0.5f,

									      ScaleAnimation.RELATIVE_TO_SELF, 0.5f);

									  //渐变动画

									  AlphaAnimation alphaAnimation = new AlphaAnimation(1.0f, 0.5f);

									  scaleAnimation.setDuration(800);

									  scaleAnimation.setRepeatCount(Animation.INFINITE);

									  alphaAnimation.setRepeatCount(Animation.INFINITE);

									  as.setDuration(800);

									  as.addAnimation(scaleAnimation);

									  as.addAnimation(alphaAnimation);

									  iv1.startAnimation(as);

									}

最外层imageView的动画

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									private void setAnim2() {

									  AnimationSet as = new AnimationSet(true);

									  //缩放动画，以中心从1.4倍放大到1.8倍

									  ScaleAnimation scaleAnimation = new ScaleAnimation(1.4f, 1.8f, 1.4f, 1.8f,

									      ScaleAnimation.RELATIVE_TO_SELF, 0.5f,

									      ScaleAnimation.RELATIVE_TO_SELF, 0.5f);

									  //渐变动画

									  AlphaAnimation alphaAnimation = new AlphaAnimation(0.5f, 0.1f);

									  scaleAnimation.setDuration(800);

									  scaleAnimation.setRepeatCount(Animation.INFINITE);

									  alphaAnimation.setRepeatCount(Animation.INFINITE);

									  as.setDuration(800);

									  as.addAnimation(scaleAnimation);

									  as.addAnimation(alphaAnimation);

									  iv2.startAnimation(as);

									}