Android 动画效果及Interpolator和AnimationListener的使用

转载http://www.itzhai.com/android-animation-used-to-achieve-control-of-animation-effects-and-use-of-interpolator-and-animationlistener.html

android:interpolator

可能有很多人不理解它的用法，文档里说的也不太清楚，其实很简单，看下面：interpolator定义一个动画的变化率（the rate of change）。这使得基本的动画效果(alpha, scale, translate, rotate）得以加速，减速，重复等。用通俗的一点的话理解就是：动画的进度使用 Interpolator 控制。interpolator 定义了动画的变化速度，可以实现匀速、正加速、负加速、无规则变加速等。Interpolator 是基类，封装了所有 Interpolator 的共同方法，它只有一个方法，即 getInterpolation (float input)，该方法 maps a point on the timeline to a multiplier to be applied to the transformations of an animation。Android 提供了几个 Interpolator 子类，实现了不同的速度曲线，如下：

AccelerateDecelerateInterpolator 在动画开始与介绍的地方速率改变比较慢，在中间的时侯加速

AccelerateInterpolator 在动画开始的地方速率改变比较慢，然后开始加速

CycleInterpolator 动画循环播放特定的次数，速率改变沿着正弦曲线

DecelerateInterpolator 在动画开始的地方速率改变比较慢，然后开始减速

LinearInterpolator 在动画的以均匀的速率改变

对于 LinearInterpolator ，变化率是个常数，即 f (x) = x.

public float getInterpolation(float input) {

return input;

}

Interpolator其他的几个子类，也都是按照特定的算法，实现了对变化率。还可以定义自己的 Interpolator 子类，实现抛物线、自由落体等物理效果。

 

Animation的4个基本动画效果

What is Animation?

public abstract class
Animation
extends Object
implements Cloneable

Abstraction for an Animation that can be applied to Views, Surfaces, or other objects.

1、AlphaAnimation：淡入淡出效果

public class
AlphaAnimation
extends Animation

An animation that controls the alpha level of an object. Useful for fading things in and out. This animation ends up changing the alpha property of aTransformation

Public Constructors
AlphaAnimation(Context context, AttributeSet attrs)
Constructor used when an AlphaAnimation is loaded from a resource.
AlphaAnimation(float fromAlpha, float toAlpha)
Constructor to use when building an AlphaAnimation from code

public class
AnimationSet
extends Animation

Represents a group of Animations that should be played together. The transformation of each individual animation are composed together into a single transform. If AnimationSet sets any properties that its children also set (for example, duration or fillBefore), the values of AnimationSet override the child values.

在代码中实现动画效果的方法：

ImageView imageView = (ImageView) findViewById(R.id.imageView1);
AnimationSet animationSet = new AnimationSet(true);
AlphaAnimation alphaAnimation = new AlphaAnimation(0, 1);
alphaAnimation.setDuration(1000);
alphaAnimation.setStartOffset(10000);
animationSet.addAnimation(alphaAnimation);
//animationSet.setStartOffset(10000);
animationSet.setFillBefore(false);
animationSet.setFillAfter(true);
imageView.startAnimation(animationSet);

在XML文件中实现动画效果的方法：

① 在res目录下创建一个anim文件夹，在里面添加一个alpha.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"android:fillAfter="true"android:fillBefore="false"><alphaandroid:fromAlpha="1.0"android:toAlpha="0.0"android:startOffset="1000"android:duration="1000" /></set>

② 在Activity中使用AnimationUtils获取Animation并进行设置：

Animation animation = AnimationUtils.loadAnimation(MainActivity.this, R.anim.alpha);
imageView.startAnimation(animation);

2、ScaleAnimation：缩放效果

public class
ScaleAnimation
extends Animation

An animation that controls the scale of an object. You can specify the point to use for the center of scaling.

Public Constructors
ScaleAnimation(Context context, AttributeSet attrs)
Constructor used when a ScaleAnimation is loaded from a resource.
ScaleAnimation(float fromX, float toX, float fromY, float toY)
Constructor to use when building a ScaleAnimation from code
ScaleAnimation(float fromX, float toX, float fromY, float toY, float pivotX, float pivotY)
Constructor to use when building a ScaleAnimation from code
ScaleAnimation(float fromX, float toX, float fromY, float toY, int pivotXType, float pivotXValue, int pivotYType, float pivotYValue)
Constructor to use when building a ScaleAnimation from code

在代码中实现动画效果：

ImageView imageView = (ImageView) findViewById(R.id.imageView1);
AnimationSet animationSet = new AnimationSet(true);
ScaleAnimation scaleAnimation = new ScaleAnimation(1, 0.5f, 1, 0.5f,Animation.RELATIVE_TO_SELF, 1f,Animation.RELATIVE_TO_SELF, 1f);
animationSet.addAnimation(scaleAnimation);
animationSet.setDuration(1000);
imageView.startAnimation(animationSet);

在XML文件中实现动画效果的方法：

① 在res的anim文件夹下，创建一个scale.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"><scale android:fromXScale="1.0"android:toXScale="0.0"android:fromYScale="1.0"android:toYScale="0.0"android:pivotX="50%"android:pivotY="50%"android:duration="2000" /></set>

② 在Activity中使用AnimationUtils获取Animation并进行设置：

Animation animation = AnimationUtils.loadAnimation(MainActivity.this, R.anim.scale);
imageView.startAnimation(animation);

3、Rotate：旋转效果

public class
RotateAnimation
extends Animation

An animation that controls the rotation of an object. This rotation takes place int the X-Y plane. You can specify the point to use for the center of the rotation, where (0,0) is the top left point. If not specified, (0,0) is the default rotation point.

Public Constructors
RotateAnimation(Context context, AttributeSet attrs)
Constructor used when a RotateAnimation is loaded from a resource.
RotateAnimation(float fromDegrees, float toDegrees)
Constructor to use when building a RotateAnimation from code.
RotateAnimation(float fromDegrees, float toDegrees, float pivotX, float pivotY)
Constructor to use when building a RotateAnimation from code
RotateAnimation(float fromDegrees, float toDegrees, int pivotXType, float pivotXValue, int pivotYType, float pivotYValue)
Constructor to use when building a RotateAnimation from code

在代码中实现动画效果：

ImageView imageView = (ImageView) findViewById(R.id.imageView1);
AnimationSet animationSet = new AnimationSet(true);
RotateAnimation rotateAnimation = new RotateAnimation(0, 360,Animation.RELATIVE_TO_PARENT, 0.5f,Animation.RELATIVE_TO_PARENT, 0.5f);
rotateAnimation.setDuration(1000);
animationSet.addAnimation(rotateAnimation);
imageView.startAnimation(animationSet);

在XML文件中实现动画效果的方法：

① 在res的anim文件夹下，创建一个rotate.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"><rotate android:fromDegrees="0"android:toDegrees="+360"android:pivotX="50%"android:pivotY="50%"android:duration="1000" />
</set>

② 在Activity中使用AnimationUtils获取Animation并进行设置：

Animation animation = AnimationUtils.loadAnimation(MainActivity.this, R.anim.rotate);
imageView.startAnimation(animation);

4、 Translate：移动效果

public class
TranslateAnimation
extends Animation

An animation that controls the position of an object.

Public Constructors
TranslateAnimation(Context context, AttributeSet attrs)
Constructor used when a TranslateAnimation is loaded from a resource.
TranslateAnimation(float fromXDelta, float toXDelta, float fromYDelta, float toYDelta)
Constructor to use when building a TranslateAnimation from code
TranslateAnimation(int fromXType, float fromXValue, int toXType, float toXValue, int fromYType, float fromYValue, int toYType, float toYValue)
Constructor to use when building a TranslateAnimation from code

在代码中实现动画效果：

ImageView imageView = (ImageView) findViewById(R.id.imageView1);
AnimationSet animationSet = new AnimationSet(true);
TranslateAnimation translateAnimation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0f,Animation.RELATIVE_TO_SELF, 1.0f,Animation.RELATIVE_TO_SELF, 0f,Animation.RELATIVE_TO_SELF, 1.0f);
translateAnimation.setDuration(1000);
animationSet.addAnimation(translateAnimation);
imageView.startAnimation(animationSet);

在XML文件中实现动画效果的方法：

① 在res的anim文件夹下，创建一个translate.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"><translateandroid:fromXDelta="0%p"android:toXDelta="100%p"android:fromYDelta="0%p"android:toYDelta="100%p"android:duration="1000" /></set>

其中100%p表示相对于父空间的位置

② 在Activity中使用AnimationUtils获取Animation并进行设置：

Animation animation = (Animation) AnimationUtils.loadAnimation(MainActivity.this, R.anim.translate);
imageView.startAnimation(animation);

也可以使用AnimationSet为一个控件添加多个动画，或者在xml文件中添加多个动画标签，以下分别使用代码和XML文件实现相同的效果：

代码中实现：

AnimationSet animationSet = new AnimationSet(false);
AlphaAnimation alpha = new AlphaAnimation(1.0f, 0.0f);
ScaleAnimation scale = new ScaleAnimation(1, 0.5f, 1, 0.5f,
Animation.RELATIVE_TO_SELF, 0.5f,
Animation.RELATIVE_TO_SELF, 0.5f);
animationSet.addAnimation(alpha);
animationSet.addAnimation(scale);
animationSet.setDuration(2000);
animationSet.setStartOffset(1000);
animationSet.setFillAfter(true);
imageView.startAnimation(animationSet);

XML实现：

alpha.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"android:shareInterpolator="true"android:fillAfter="true"><alphaandroid:fromAlpha="1.0"android:toAlpha="0.0"android:startOffset="1000"android:fillAfter="true"android:duration="2000" /><scale android:fromXScale="1.0"android:toXScale="0.5"android:fromYScale="1.0"android:toYScale="0.5"android:pivotX="50%"android:pivotY="50%"android:startOffset="1000"android:duration="2000" />
</set>

Activity中的代码：

Animation animation = AnimationUtils.loadAnimation(MainActivity.this, R.anim.alpha);
imageView.startAnimation(animation);

Interpolator的使用

什么是Interpolator

public class
Interpolator
extends Object

Interpolator定义了动画变化的速率或规律，其具体的实现可以使用以下子类：

AccelerateDecelerateInterpolator：

public class
AccelerateDecelerateInterpolator
extends Object
implements Interpolator

An interpolator where the rate of change starts and ends slowly but accelerates through the middle.

AccelerateInterpolater：

public class
AccelerateInterpolator
extends Object
implements Interpolator

An interpolator where the rate of change starts out slowly and and then accelerates.

CycleInterpolator：

public class
CycleInterpolator
extends Object
implements Interpolator

Repeats the animation for a specified number of cycles. The rate of change follows a sinusoidal pattern.

DecelerateInterpolator：

public class
DecelerateInterpolator
extends Object
implements Interpolator

An interpolator where the rate of change starts out quickly and and then decelerates.

LinearInterpolator：

public class
LinearInterpolator
extends Object
implements Interpolator

An interpolator where the rate of change is constant.

这些Interpolator可以在代码或XML文件中定义：

XML文件定义在set标签里或每个动画标签

set标签中定义：

<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"android:shareInterpolator="true"android:fillAfter="true">

每个动画标签中定义：

<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"android:shareInterpolator="false"android:fillAfter="true"><alphaandroid:interpolator="@android:anim/accelerate_interpolator"android:fromAlpha="1.0"android:toAlpha="0.0"android:startOffset="1000"android:fillAfter="true"android:duration="2000" /><scaleandroid:interpolator="@android:anim/accelerate_decelerate_interpolator"android:fromXScale="1.0"android:toXScale="0.5"android:fromYScale="1.0"android:toYScale="0.5"android:pivotX="50%"android:pivotY="50%"android:startOffset="1000"android:duration="2000" />
</set>

在代码中设置：

AnimationSet animationSet = new AnimationSet(true);
animationSet.setInterpolator(new AccelerateInterpolator());

或者分别为每个动画设置：

AnimationSet animationSet = new AnimationSet(false);
AlphaAnimation alpha = new AlphaAnimation(1.0f, 0.0f);
alpha.setInterpolator(new AccelerateInterpolator());
ScaleAnimation scale = new ScaleAnimation(1, 0.5f, 1, 0.5f,Animation.RELATIVE_TO_SELF, 0.5f,Animation.RELATIVE_TO_SELF, 0.5f);
scale.setInterpolator(new AccelerateDecelerateInterpolator());

Frame-By-Frame Animations的使用

① 准备4张图片run1.png,run2.png,run3.png,run4.png分别放到res的三个drawable文件夹中
② 在res的drawable-ldpi目录下创建一个anim_run.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android"android:oneshot="false"><item android:drawable="@drawable/run1" android:duration="100" /><item android:drawable="@drawable/run2" android:duration="100" /><item android:drawable="@drawable/run3" android:duration="100" /><item android:drawable="@drawable/run4" android:duration="100" />
</animation-list>

③ 在Activity中使用xml文件设置ImageView控件imageView的背景源，并获取AnimationDrawable进行显示动画：

imageView.setBackgroundResource(R.drawable.anim_run);
AnimationDrawable animationDrawable = (AnimationDrawable)imageView.getBackground();
animationDrawable.start();

使用LayoutAnimationController设置ListView的动画

什么是LayoutAnimationController？

public class
LayoutAnimationController
extends Object

A layout animation controller is used to animated a layout's, or a view group's, children. Each child uses the same animation but for every one of them, the animation starts at a different time. A layout animation controller is used by ViewGroup to compute the delay by which each child's animation start must be offset. The delay is computed by using characteristics of each child, like its index in the view group. This standard implementation computes the delay by multiplying a fixed amount of miliseconds by the index of the child in its parent view group. Subclasses are supposed to override getDelayForView(android.view.View) to implement a different way of computing the delay. For instance, aGridLayoutAnimationController will compute the delay based on the column and row indices of the child in its parent view group. Information used to compute the animation delay of each child are stored in an instance of LayoutAnimationController.AnimationParameters, itself stored in theViewGroup.LayoutParams of the view.

在使用LayoutAnimationController控制ListView控件的样式效果的方法：

① 在res的anim文件夹中创建一个list_anim.xml文件用于控制ListView控件的动画：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"android:interpolator="@android:anim/accelerate_interpolator"android:shareInterpolator="true"><scale android:fromXScale="0.0"android:toXScale="1.0"android:fromYScale="0.0"android:toYScale="1.0"android:pivotX="50%"android:pivotY="50%"android:duration="1000" />
</set>

② 创建一个布局文件item.xml用于设置ListView的item的样式：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent" android:layout_height="fill_parent"android:orientation="horizontal" android:paddingLeft="10dip"android:paddingRight="10dip" android:paddingTop="1dip"android:paddingBottom="1dip"><TextView android:id="@+id/user_name" android:layout_width="180dip"android:layout_height="30dip"android:textSize="10pt"android:singleLine="true" /><TextView android:id="@+id/user_id" android:layout_width="fill_parent"android:layout_height="fill_parent"android:textSize="10pt"android:singleLine="true"/>
</LinearLayout>

③ 在主Activity的布局文件main.xml中添加一个ListView

<ListViewandroid:id="@id/android:list"android:layout_width="fill_parent"android:layout_height="wrap_content"android:scrollbars="vertical"android:layoutAnimation="@anim/anim_layout"/>

④ 创建一个MainActivity继承ListActivity，并在onCreate方法中添加如下代码：

ListView listView = getListView();List<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
HashMap<String, String> hm1 = new HashMap<String, String>();
hm1.put("user_name", "arthinking");
hm1.put("user_id", "001");
HashMap<String, String> hm2 = new HashMap<String, String>();
hm2.put("user_name", "Jason");
hm2.put("user_id", "002");
list.add(hm1);
list.add(hm2);SimpleAdapter simpleAdapter = new SimpleAdapter(this, list,R.layout.item, new String[] { "user_name", "user_id" },new int[] { R.id.user_name, R.id.user_id });
listView.setAdapter(simpleAdapter);//通过Animation获取LayoutAnimationController对ListView进行设置
Animation animation = (Animation)AnimationUtils.loadAnimation(MainActivity.this, R.anim.list_anim);
LayoutAnimationController lac = new LayoutAnimationController(animation);
lac.setOrder(LayoutAnimationController.ORDER_NORMAL);
lac.setDelay(0.5f);
listView.setLayoutAnimation(lac);

这样，运行程序，显示的ListView就会按照xml文件中预置的动画效果显示了。

也可以通过xml文件进行设置动画：

① 在以上步骤的基础之上，在res/anim文件夹下创建一个anim_layout.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<layoutAnimation xmlns:android="http://schemas.android.com/apk/res/android"android:delay="1"android:animationOrder="normal"android:animation="@anim/list_anim" />

② main在布局文件的的ListView添加如下属性：

android:layoutAnimation="@anim/anim_layout"

这样就在把MainActivity的onCreate()方法中的
//通过Animation获取LayoutAnimationController对ListView进行设置
注释后的代码删除了，直接使用xml进行动画的控制。

AnimationListener的使用

public static interface
Animation.AnimationListener
android.view.animation.Animation.AnimationListener

An animation listener receives notifications from an animation. Notifications indicate animation related events, such as the end or the repetition of the animation.

包含以下的三个方法：

onAnimationEnd(Animation animation)
Notifies the end of the animation.
onAnimationRepeat(Animation animation)
Notifies the repetition of the animation.
onAnimationStart(Animation animation)
Notifies the start of the animation.

AnimationListener在控件中的使用：

① 可以为一个Button添加一个事件：

button.setOnClickListener(new TestAnimationListener());

② 接下来是编写这个TestAnimationListener类，继承AnimationListener，并覆盖里面的三个方法：

//这里获取控件组，R.id.layoutId为main.xml的整体布局标签的id属性值
ViewGroup viewGroup = (ViewGroup)findViewById(R.id.layoutId);private class RemoveAnimationListener implements AnimationListener{//该方法在淡出效果执行结束之后被调用@Overridepublic void onAnimationEnd(Animation animation) {//假设这里要在动画执行完之后删除一个TextViewviewGroup.removeView(textView);}@Overridepublic void onAnimationRepeat(Animation animation) {System.out.println("onAnimationRepeat");}@Overridepublic void onAnimationStart(Animation animation) {System.out.println("onAnimationStart");}}

③ 同样的，在动画效果中添加控件可以按照如下实现

ScaleAnimation scale = new ScaleAnimation(1, 0.5f, 1, 0.5f,
scale.setDuration(1000);
scale.setStartOffset(100);
TextView textView = new TextView(MainActivity.this);
textView.setText("add");
viewGroup.addView(textView, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
textView.startAnimation(scale);

（特别说明：本文部分内容是在观看marschen的Android视频教程时做的笔记，感谢marschen推出的视频教程，这里也推荐给大家：http://www.marschen.com/portal.php）

除了文章中有特别说明，均为IT宅原创文章，转载请以链接形式注明出处。
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关键字: AlphaAnimation, Android, AnimationListener, Interpolator, RotateAnimation, ScaleAnimation, TranslateAnimation