依然是github开源项目：WaitingDots
这个项目代码不多，实现的非常easy。可是非常有意思由于动画的基本元素不是画出来的，而是使用了spannableString来实现。

• DotsTextView.java
• JumpingSpan.java
• MainActivity.java
  DotstextView是动画的实现主体。
  JumpingSpan是基本元素，是动画中的插件
  MainActivity中仅仅要在布局中引入DotsTextView就可以。
  下面是切割线，show code:

package pl.tajchert.sample;import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.FontMetricsInt;
import android.text.style.ReplacementSpan;
/* ReplacementSpan真是一个挺奇妙的东西。在官方api上介绍甚少*几个主要功能函数也是do nothing.* 本例中自己定义的translationX,translationY没有发挥作用。假设给两个变量赋值* 那么第一个JumpingSpan距离前面元素距离增大，这里这样使用是为了让每一个"."为一个单独的单元进行独立操作*/
public class JumpingSpan extends ReplacementSpan {private float translationX = 0;private float translationY = 0;@Overridepublic int getSize(Paint paint, CharSequence text, int start, int end, FontMetricsInt fontMetricsInt) {return (int) paint.measureText(text, start, end);}@Overridepublic void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint) {canvas.drawText(text, start, end, x + translationX, y + translationY, paint);}public void setTranslationX(float translationX) {this.translationX = translationX;}public void setTranslationY(float translationY) {this.translationY = translationY;}
}

package pl.tajchert.sample;import android.animation.Animator;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.animation.TypeEvaluator;
import android.animation.ValueAnimator;
import android.animation.ValueAnimator.AnimatorUpdateListener;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Handler;
import android.os.Looper;
import android.text.SpannableString;
import android.text.Spanned;
import android.util.AttributeSet;
import android.widget.TextView;import pl.tajchert.waitingdots.R;public class DotsTextView extends TextView {private JumpingSpan dotOne;private JumpingSpan dotTwo;private JumpingSpan dotThree;private int showSpeed = 700;private int jumpHeight;private boolean autoPlay;private boolean isPlaying;private boolean isHide;private int period;private long startTime;private boolean lockDotOne;private boolean lockDotTwo;private boolean lockDotThree;private Handler handler;private AnimatorSet mAnimatorSet = new AnimatorSet();private float textWidth;public DotsTextView(Context context) {super(context);init(context, null);}public DotsTextView(Context context, AttributeSet attrs) {super(context, attrs);init(context, attrs);}public DotsTextView(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init(context, attrs);}private void init(Context context, AttributeSet attrs) {handler = new Handler(Looper.getMainLooper());//自己定义属性if (attrs != null) {TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.WaitingDots);period = typedArray.getInt(R.styleable.WaitingDots_period, 6000);jumpHeight = typedArray.getInt(R.styleable.WaitingDots_jumpHeight, (int) (getTextSize() / 4));autoPlay = typedArray.getBoolean(R.styleable.WaitingDots_autoplay, true);typedArray.recycle();}dotOne = new JumpingSpan();dotTwo = new JumpingSpan();dotThree = new JumpingSpan();//将每一个点设置为jumpingSpan类型SpannableString spannable = new SpannableString("...");spannable.setSpan(dotOne, 0, 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);spannable.setSpan(dotTwo, 1, 2, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);spannable.setSpan(dotThree, 2, 3, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);setText(spannable, BufferType.SPANNABLE);textWidth = getPaint().measureText(".", 0, 1);//一下两个是把updateListener加到点1上，通过它来进行刷新动作ObjectAnimator dotOneJumpAnimator = createDotJumpAnimator(dotOne, 0);dotOneJumpAnimator.addUpdateListener(new AnimatorUpdateListener() {@Overridepublic void onAnimationUpdate(ValueAnimator valueAnimator) {invalidate();}});//这里通过animationSet来控制三个点的组合动作mAnimatorSet.playTogether(dotOneJumpAnimator, createDotJumpAnimator(dotTwo,period / 6), createDotJumpAnimator(dotThree, period * 2 / 6));isPlaying = autoPlay;if(autoPlay) {start();}}public void start() {isPlaying = true;//一旦開始就INFINITEsetAllAnimationsRepeatCount(ValueAnimator.INFINITE);mAnimatorSet.start();}/*动画的实现核心*@param jumpingSpan 传入点。* @delay 动画执行延迟，通过这个參数让三个点进行有时差的运动*/private ObjectAnimator createDotJumpAnimator(JumpingSpan jumpingSpan, long delay) {ObjectAnimator jumpAnimator = ObjectAnimator.ofFloat(jumpingSpan, "translationY", 0, -jumpHeight);/*setEvaluator这个重要。功能是为了通过方程来平滑的实现点运动的“节奏感”，能够试试把这段去掉。你会发现点会以默认的速度上下运动，特别生硬。TypeEvaluator中的evaluate能够计算出点的当前位置。通过对当前点的计算间接设计了点的轨迹运动，和时间插值TimeInterpolator达到同样的效果。就好比你不知道速度可是你知道每秒所在的位置相当于速度了。

这个计算方法是这种：能够參见这个博文 http://blog.csdn.net/serapme/article/details/47006049 ValueAnimator还封装了一个TypeAnimator。依据開始、结束值与TimeIniterpolator计算得到的值计算出属性值。 ValueAnimator依据动画已进行的时间跟动画总时间（duration）的比计算出一个时间因子（0~1），然后依据TimeInterpolator计算出还有一个因子，最后TypeAnimator通过这个因子计算出属性值，如上例中10ms时： 首先计算出时间因子，即经过的时间百分比：t=10ms/40ms=0.25 经插值计算(inteplator)后的插值因子:大约为0.15。上述样例中用了AccelerateDecelerateInterpolator，计算公式为（input即为时间因子）： (Math.cos((input + 1) * Math.PI) / 2.0f) + 0.5f; 最后依据TypeEvaluator计算出在10ms时的属性值：0.15*（40-0）=6pixel。上例中TypeEvaluator为FloatEvaluator，计算方法为 ： public Float evaluate(float fraction, Number startValue, Number endValue) { float startFloat = startValue.floatValue(); return startFloat + fraction * (endValue.floatValue() - startFloat); } */

jumpAnimator.setEvaluator(new TypeEvaluator<Number>() { @Override public Number evaluate(float fraction, Number from, Number to) { return Math.max(0, Math.sin(fraction * Math.PI * 2)) * (to.floatValue() - from.floatValue()); } }); jumpAnimator.setDuration(period); jumpAnimator.setStartDelay(delay); jumpAnimator.setRepeatCount(ValueAnimator.INFINITE); jumpAnimator.setRepeatMode(ValueAnimator.RESTART); return jumpAnimator; } //下面部分非核心功能也没难度就不凝视了~主要是由于懒~ public void stop() { isPlaying = false; setAllAnimationsRepeatCount(0); } private void setAllAnimationsRepeatCount(int repeatCount) { for (Animator animator : mAnimatorSet.getChildAnimations()) { if (animator instanceof ObjectAnimator) { ((ObjectAnimator) animator).setRepeatCount(repeatCount); } } } public void hide() { createDotHideAnimator(dotThree, 2).start(); ObjectAnimator dotTwoMoveRightToLeft = createDotHideAnimator(dotTwo, 1); dotTwoMoveRightToLeft.addUpdateListener(new AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator valueAnimator) { invalidate(); } }); dotTwoMoveRightToLeft.start(); isHide = true; } public void show() { ObjectAnimator dotThreeMoveRightToLeft = createDotShowAnimator(dotThree, 2); dotThreeMoveRightToLeft.start(); ObjectAnimator dotTwoMoveRightToLeft = createDotShowAnimator(dotTwo, 1); dotTwoMoveRightToLeft.addUpdateListener(new AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator valueAnimator) { invalidate(); } }); dotTwoMoveRightToLeft.start(); isHide = false; } private ObjectAnimator createDotHideAnimator(JumpingSpan span, float widthMultiplier) { return createDotHorizontalAnimator(span, 0, -textWidth * widthMultiplier); } private ObjectAnimator createDotShowAnimator(JumpingSpan span, int widthMultiplier) { return createDotHorizontalAnimator(span, -textWidth * widthMultiplier, 0); } private ObjectAnimator createDotHorizontalAnimator(JumpingSpan span, float from, float to) { ObjectAnimator dotThreeMoveRightToLeft = ObjectAnimator.ofFloat(span, "translationX", from, to); dotThreeMoveRightToLeft.setDuration(showSpeed); return dotThreeMoveRightToLeft; } public void showAndPlay() { show(); start(); } public void hideAndStop() { hide(); stop(); } public boolean isHide() { return isHide; } public boolean isPlaying() { return isPlaying; } public void setJumpHeight(int jumpHeight) { this.jumpHeight = jumpHeight; } public void setPeriod(int period) { this.period = period; } }

毫无疑问在activity中引入布局中就可以。

dotsTextView = (DotsTextView) findViewById(R.id.dots);

一个简单使用的loadingview。