Android之动画解析

extends
Animator

类概述

这个类提供了一个用于计算动画值并将其设置为目标对象的动画的简单时序引擎。

有一个单一的定时脉冲，所有动画使用。它运行在一个自定义处理程序中，以确保用户界面线程中的属性发生更改。

默认情况下，ValueAnimator采用非线性时域插值，通过AccelerateDecelerateInterpolator类，加速和减速的动画。这种行为可以通过调用setinterpolator改变（timeinterpolator）。

动画师可以创建代码或资源文件。这里是一个ValueAnimator资源文件的一个实例：

<animator xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:valueFrom="1"
android:valueTo="0"
android:valueType="floatType"
android:repeatCount="1"
android:repeatMode="reverse"/>

它也可以结合使用PropertyValuesHolder和帧标签来创建一个多步骤的动画资源。请注意，您可以指定明确的分数值（从0到1）为每个关键帧来确定时，在整个时间，动画应该到达那个值。或者，你可以把分数和关键帧将在总时间平均分配

<animator xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:repeatCount="1"
android:repeatMode="reverse">
<propertyValuesHolder>
<keyframe android:fraction="0" android:value="1"/>
<keyframe android:fraction=".2" android:value=".4"/>
<keyframe android:fraction="1" android:value="0"/>
</propertyValuesHolder>
</animator>

Nested Classes

interface

ValueAnimator.AnimatorUpdateListener

Implementors of this interface can add themselves as update listeners to an ValueAnimator instance to receive callbacks on every animation frame, after the current frame's values have been calculated for that ValueAnimator .

Constants

int	INFINITE	This value used used with the setRepeatCount(int) property to repeat the animation indefinitely.   这个值用来与setrepeatcount（int）属性重复动画无限期。
int	RESTART	When the animation reaches the end and repeatCount is INFINITE or a positive value, the animation restarts from the beginning.
int	REVERSE	When the animation reaches the end and repeatCount is INFINITE or a positive value, the animation reverses direction on every iteration. 逆转

Public Constructors
ValueAnimator()

Creates a new ValueAnimator object.  创建一个新的ValueAnimator对象。
Public Methods：

void	addUpdateListener(ValueAnimator.AnimatorUpdateListener listener)Adds a listener to the set of listeners that are sent update events through the life of an animation.
void	cancel()Cancels the animation.取消动画。
ValueAnimator	clone()Creates and returns a copy of this Object .创建并返回该对象的副本。
void	end()Ends the animation.结束动画。
float	getAnimatedFraction()Returns the current animation fraction, which is the elapsed/interpolated fraction used in the most recent frame update on the animation.
Object	4000 getAnimatedValue()The most recent value calculated by this ValueAnimator when there is just one property being animated.
Object	getAnimatedValue(String propertyName)The most recent value calculated by this ValueAnimator for propertyName .
long	getCurrentPlayTime()Gets the current position of the animation in time, which is equal to the current time minus the time that the animation started.获取当前播放时间
long	getDuration()Gets the length of the animation.获取动画长度。
static long	getFrameDelay()The amount of time, in milliseconds, between each frame of the animation.每一帧的之间的时间
TimeInterpolator	getInterpolator()Returns the timing interpolator that this ValueAnimator uses.返回定时插补
int	getRepeatCount()Defines how many times the animation should repeat.获取动画重复的次数
int	getRepeatMode()Defines what this animation should do when it reaches the end.
long	getStartDelay()The amount of time, in milliseconds, to delay starting the animation after start() is called.延迟多少毫米开始
PropertyValuesHolder[]	getValues()Returns the values that this ValueAnimator animates between.
boolean	isRunning()Returns whether this Animator is currently running (having been started and gone past any initial startDelay period and not yet ended).
boolean	isStarted()Returns whether this Animator has been started and not yet ended.
staticValueAnimator	ofArgb(int... values)Constructs and returns a ValueAnimator that animates between color values.
staticValueAnimator	ofFloat(float... values)Constructs and returns a ValueAnimator that animates between float values.
staticValueAnimator	ofInt(int... values)Constructs and returns a ValueAnimator that animates between int values.
staticValueAnimator	ofObject(TypeEvaluator evaluator, Object... values)Constructs and returns a ValueAnimator that animates between Object values.
staticValueAnimator	ofPropertyValuesHolder(PropertyValuesHolder... values)Constructs and returns a ValueAnimator that animates between the values specified in the PropertyValuesHolder objects.
void	pause()Pauses a running animation.
void	removeAllUpdateListeners()Removes all listeners from the set listening to frame updates for this animation.
void	removeUpdateListener(ValueAnimator.AnimatorUpdateListener listener)Removes a listener from the set listening to frame updates for this animation.
void	resume()Resumes a paused animation, causing the animator to pick up where it left off when it was paused.
void	reverse()Plays the ValueAnimator in reverse.
void	setCurrentFraction(float fraction)Sets the position of the animation to the specified fraction.
void	setCurrentPlayTime(long playTime)Sets the position of the animation to the specified point in time.
ValueAnimator	setDuration(long duration)Sets the length of the animation.
void	setEvaluator(TypeEvaluator value)The type evaluator to be used when calculating the animated values of this animation.
void	setFloatValues(float... values)Sets float values that will be animated between.
static void	setFrameDelay(long frameDelay)The amount of time, in milliseconds, between each frame of the animation.
void	setIntValues(int... values)Sets int values that will be animated between.
void	setInterpolator(TimeInterpolator value)The time interpolator used in calculating the elapsed fraction of this animation.
void	setObjectValues(Object... values)Sets the values to animate between for this animation.
void	setRepeatCount(int value)Sets how many times the animation should be repeated.
void	setRepeatMode(int value)Defines what this animation should do when it reaches the end.
void	setStartDelay(long startDelay)The amount of time, in milliseconds, to delay starting the animation after start() is called.
void	setValues(PropertyValuesHolder... values)Sets the values, per property, being animated between.
void	start()Starts this animation.
String	toString()Returns a string containing a concise, human-readable description of this object.

更详细的内容请参考http://blog.csdn.net/guolin_blog/article/details/43536355
http://blog.csdn.net/guolin_blog/article/details/43816093 http://blog.csdn.net/guolin_blog/article/details/44171115