本文实例为大家分享了Android自定义控件之三点循环缩放的具体代码，供大家参考，具体内容如下

效果图如上，就是三点循环的变大、变小

package com.example.dotdemo;import java.util.ArrayList;import java.util.List;import android.animation.Animator;import android.animation.AnimatorListenerAdapter;import android.animation.ObjectAnimator;import android.animation.ValueAnimator;import android.annotation.SuppressLint;import android.annotation.TargetApi;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Canvas;import android.graphics.drawable.Drawable;import android.os.Build;import android.util.AttributeSet;import android.util.Log;import android.view.View;import android.view.animation.AccelerateDecelerateInterpolator;@TargetApi(Build.VERSION_CODES.HONEYCOMB)@SuppressLint("NewApi")public class DilatingDotsProgressBar extends View { public static final String TAG = DilatingDotsProgressBar.class.getSimpleName(); public static final double START_DELAY_FACTOR = 0.35; private static final float DEFAULT_GROWTH_MULTIPLIER = 1.75f; private static final int MIN_SHOW_TIME = 500; // ms private static final int MIN_DELAY = 500; // ms private int mDotColor; private int mAnimationDuration; private int mWidthBetweenDotCenters; private int mNumberDots; private float mDotRadius; private float mDotScaleMultiplier; private float mDotMaxRadius; private float mHorizontalSpacing; private long mStartTime = -1; private boolean mShouldAnimate; private boolean mDismissed = false; private ArrayList<DilatingDotDrawable> mDrawables = new ArrayList<DilatingDotDrawable>(); private final List<Animator> mAnimations = new ArrayList<Animator>(); /** delayed runnable to stop the progress */ private final Runnable mDelayedHide = new Runnable() { @Override public void run() { mStartTime = -1; setVisibility(View.GONE); stopAnimations(); } }; /** delayed runnable to start the progress */ private final Runnable mDelayedShow = new Runnable() { @Override public void run() { if (!mDismissed) { mStartTime = System.currentTimeMillis(); setVisibility(View.VISIBLE); startAnimations(); } } }; public DilatingDotsProgressBar(Context context) { this(context, null); } public DilatingDotsProgressBar(Context context, AttributeSet attrs) { this(context, attrs, 0); } public DilatingDotsProgressBar(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(attrs); } private void init(AttributeSet attrs) { TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.DilatingDotsProgressBar); mNumberDots = a.getInt(R.styleable.DilatingDotsProgressBar_dd_numDots, 3); mDotRadius = a.getDimension(R.styleable.DilatingDotsProgressBar_android_radius, 8); mDotColor = a.getColor(R.styleable.DilatingDotsProgressBar_android_color, 0xff9c27b0); mDotScaleMultiplier = a.getFloat(R.styleable.DilatingDotsProgressBar_dd_scaleMultiplier, DEFAULT_GROWTH_MULTIPLIER); mAnimationDuration = a.getInt(R.styleable.DilatingDotsProgressBar_dd_animationDuration, 300); mHorizontalSpacing = a.getDimension(R.styleable.DilatingDotsProgressBar_dd_horizontalSpacing, 12); boolean isShow = a.getBoolean(R.styleable.DilatingDotsProgressBar_dd_show_now, false); a.recycle(); mShouldAnimate = false; calculateMaxRadius(); calculateWidthBetweenDotCenters(); initDots(); updateDots(); if (isShow) { showNow(); } } @Override protected void onSizeChanged(final int w, final int h, final int oldw, final int oldh) { super.onSizeChanged(w, h, oldw, oldh); if (computeMaxHeight() != h || w != computeMaxWidth()) { updateDots(); } } @Override public void onDetachedFromWindow() { super.onDetachedFromWindow(); removeCallbacks(); } private void removeCallbacks() { removeCallbacks(mDelayedHide); removeCallbacks(mDelayedShow); } public void reset() { hideNow(); } /** * Hide the progress view if it is visible. The progress view will not be * hidden until it has been shown for at least a minimum show time. If the * progress view was not yet visible, cancels showing the progress view. */ public void hide() { hide(MIN_SHOW_TIME); } public void hide(int delay) { mDismissed = true; removeCallbacks(mDelayedShow); long diff = System.currentTimeMillis() - mStartTime; if ((diff >= delay) || (mStartTime == -1)) { mDelayedHide.run(); } else { if ((delay - diff) <= 0) { mDelayedHide.run(); } else { postDelayed(mDelayedHide, delay - diff); } } } /** * Show the progress view after waiting for a minimum delay. If * during that time, hide() is called, the view is never made visible. */ @SuppressWarnings ("unused") public void show() { show(MIN_DELAY); } @SuppressWarnings ("unused") public void showNow() { show(0); } @SuppressWarnings ("unused") public void hideNow() { hide(0); } public void show(int delay) { mStartTime = -1; mDismissed = false; removeCallbacks(mDelayedHide); if (delay == 0) { mDelayedShow.run(); } else { postDelayed(mDelayedShow, delay); } } @Override protected void onDraw(Canvas canvas) { if (shouldAnimate()) { for (DilatingDotDrawable dot : mDrawables) { dot.draw(canvas); } } } @Override protected boolean verifyDrawable(final Drawable who) { if (shouldAnimate()) { return mDrawables.contains(who); } return super.verifyDrawable(who); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { setMeasuredDimension((int) computeMaxWidth(), (int) computeMaxHeight()); } private float computeMaxHeight() { return mDotMaxRadius * 2; } private float computeMaxWidth() { return computeWidth() + ((mDotMaxRadius - mDotRadius) * 2); } private float computeWidth() { return (((mDotRadius * 2) + mHorizontalSpacing) * mDrawables.size()) - mHorizontalSpacing; } private void calculateMaxRadius() { mDotMaxRadius = mDotRadius * mDotScaleMultiplier; } private void calculateWidthBetweenDotCenters() { mWidthBetweenDotCenters = (int) (mDotRadius * 2) + (int) mHorizontalSpacing; } @SuppressLint("NewApi") private void initDots() { mDrawables.clear(); mAnimations.clear(); Log.i("lcf", "mAnimationDuration = "+mAnimationDuration ); for (int i = 1; i <= mNumberDots; i++) { final DilatingDotDrawable dot = new DilatingDotDrawable(mDotColor, mDotRadius, mDotMaxRadius); dot.setCallback(this); mDrawables.add(dot); ValueAnimator growAnimator = ObjectAnimator.ofFloat(dot, "radius", mDotRadius, mDotMaxRadius, mDotRadius); growAnimator.setDuration(mAnimationDuration); growAnimator.setInterpolator(new AccelerateDecelerateInterpolator()); if (i == mNumberDots) { growAnimator.addListener(new AnimatorListenerAdapter() { @TargetApi(Build.VERSION_CODES.HONEYCOMB) @Override public void onAnimationEnd(Animator animation) { if (shouldAnimate()) { startAnimations();//注意这个地方，是从新开始启动动画 } } }); } growAnimator.setStartDelay((i - 1) * (int) (START_DELAY_FACTOR * mAnimationDuration)); mAnimations.add(growAnimator); } } @SuppressLint("NewApi") private void updateDots() { if (mDotRadius <= 0) { mDotRadius = getHeight() / 2 / mDotScaleMultiplier; } int left = (int) (mDotMaxRadius - mDotRadius); int right = (int) (left + mDotRadius * 2) + 2; int top = 0; int bottom = (int) (mDotMaxRadius * 2) + 2; for (int i = 0; i < mDrawables.size(); i++) { final DilatingDotDrawable dot = mDrawables.get(i); dot.setRadius(mDotRadius); dot.setBounds(left, top, right, bottom); ValueAnimator growAnimator = (ValueAnimator) mAnimations.get(i); growAnimator.setFloatValues(mDotRadius, mDotRadius * mDotScaleMultiplier, mDotRadius); left += mWidthBetweenDotCenters; right += mWidthBetweenDotCenters; } } protected void startAnimations() { mShouldAnimate = true; for (Animator anim : mAnimations) { anim.start(); } } protected void stopAnimations() { mShouldAnimate = false; removeCallbacks(); for (Animator anim : mAnimations) { anim.cancel(); } } protected boolean shouldAnimate() { return mShouldAnimate; } // ------------------------------- // ------ Getters & Setters ------ // ------------------------------- public void setDotRadius(float radius) { reset(); mDotRadius = radius; calculateMaxRadius(); calculateWidthBetweenDotCenters(); setupDots(); } public void setDotSpacing(float horizontalSpacing) { reset(); mHorizontalSpacing = horizontalSpacing; calculateWidthBetweenDotCenters(); setupDots(); } public void setGrowthSpeed(int growthSpeed) { reset(); mAnimationDuration = growthSpeed; setupDots(); } public void setNumberOfDots(int numDots) { reset(); mNumberDots = numDots; setupDots(); } public void setDotScaleMultpiplier(float multplier) { reset(); mDotScaleMultiplier = multplier; calculateMaxRadius(); setupDots(); } public void setDotColor(int color) { mDotColor = color; for (DilatingDotDrawable dot : mDrawables) { dot.setColor(mDotColor); } } private void setupDots() { initDots(); updateDots(); showNow(); } public int getDotGrowthSpeed() { return mAnimationDuration; } public float getDotRadius() { return mDotRadius; } public float getHorizontalSpacing() { return mHorizontalSpacing; } public int getNumberOfDots() { return mNumberDots; } public float getDotScaleMultiplier() { return mDotScaleMultiplier; }}package com.example.dotdemo;import android.annotation.SuppressLint;import android.graphics.Canvas;import android.graphics.ColorFilter;import android.graphics.Paint;import android.graphics.PixelFormat;import android.graphics.Rect;import android.graphics.drawable.Drawable;@SuppressLint("Override")public class extends Drawable { private static final String TAG = DilatingDotDrawable.class.getSimpleName(); private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); private float radius; private float maxRadius; final Rect mDirtyBounds = new Rect(0, 0, 0, 0); public DilatingDotDrawable(final int color, final float radius, final float maxRadius) { mPaint.setColor(color); mPaint.setStyle(Paint.Style.FILL); mPaint.setStrokeCap(Paint.Cap.ROUND); mPaint.setStrokeJoin(Paint.Join.ROUND); this.radius = radius; setMaxRadius(maxRadius); } @Override public void draw(Canvas canvas) { final Rect bounds = getBounds(); canvas.drawCircle(bounds.centerX(), bounds.centerY(), radius - 1, mPaint); } @Override public void setAlpha(int alpha) { if (alpha != mPaint.getAlpha()) { mPaint.setAlpha(alpha); invalidateSelf(); } } @Override public void setColorFilter(ColorFilter colorFilter) { mPaint.setColorFilter(colorFilter); invalidateSelf(); } @Override public int getOpacity() { return PixelFormat.TRANSLUCENT; } public void setColor(int color) { mPaint.setColor(color); invalidateSelf(); } public void setRadius(float radius) { this.radius = radius; invalidateSelf(); } public float getRadius() { return radius; } @Override public int getIntrinsicWidth() { return (int) (maxRadius * 2) + 2; } @Override public int getIntrinsicHeight() { return (int) (maxRadius * 2) + 2; } public void setMaxRadius(final float maxRadius) { this.maxRadius = maxRadius; mDirtyBounds.bottom = (int) (maxRadius * 2) + 2; mDirtyBounds.right = (int) (maxRadius * 2) + 2; } public Rect getDirtyBounds() { return mDirtyBounds; } @Override protected void onBoundsChange(final Rect bounds) { super.onBoundsChange(bounds); mDirtyBounds.offsetTo(bounds.left, bounds.top); }}

源码下载：Android 多点循环缩放

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