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
          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
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
<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
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
@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
@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
<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

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
<?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
<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
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
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);
}
效果图

相比较而言,自定义view的效果更好点,动画实现起来更方便点。
两种方式实现的扩散效果介绍完毕,具体项目里还是要按需变动的。
总结
以上所述是小编给大家介绍的Android 实现圆圈扩散水波动画效果两种方法,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对自由互联网站的支持!
