Android 動畫效果及Interpolator和AnimationListener的使用

轉載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，文檔里說的也不太清楚，其實很簡單，看下面：interpolator定義一個動畫的變化率（the rate of change）。這使得基本的動畫效果(alpha, scale, translate, rotate）得以加速，減速，重復等。用通俗的一點的話理解就是：動畫的進度使用 Interpolator 控制。interpolator 定義了動畫的變化速度，可以實現勻速、正加速、負加速、無規則變加速等。Interpolator 是基類，封裝了所有 Interpolator 的共同方法，它只有一個方法，即 getInterpolation (float input)，該方法 maps a point on the timeline to a multiplier to be applied to the transformations of an animation。Android 提供了幾個 Interpolator 子類，實現了不同的速度曲線，如下：

AccelerateDecelerateInterpolator 在動畫開始與介紹的地方速率改變比較慢，在中間的時侯加速

AccelerateInterpolator 在動畫開始的地方速率改變比較慢，然后開始加速

CycleInterpolator 動畫循環播放特定的次數，速率改變沿著正弦曲線

DecelerateInterpolator 在動畫開始的地方速率改變比較慢，然后開始減速

LinearInterpolator 在動畫的以均勻的速率改變

對于 LinearInterpolator ，變化率是個常數，即 f (x) = x.

public float getInterpolation(float input) {

return input;

}

Interpolator其他的幾個子類，也都是按照特定的算法，實現了對變化率。還可以定義自己的 Interpolator 子類，實現拋物線、自由落體等物理效果。

?

Animation的4個基本動畫效果

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.

在代碼中實現動畫效果的方法：

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文件中實現動畫效果的方法：

① 在res目錄下創建一個anim文件夾，在里面添加一個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獲取Animation并進行設置：

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

2、ScaleAnimation：縮放效果

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

在代碼中實現動畫效果：

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文件中實現動畫效果的方法：

① 在res的anim文件夾下，創建一個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獲取Animation并進行設置：

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

3、Rotate：旋轉效果

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

在代碼中實現動畫效果：

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文件中實現動畫效果的方法：

① 在res的anim文件夾下，創建一個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獲取Animation并進行設置：

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

4、 Translate：移動效果

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

在代碼中實現動畫效果：

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文件中實現動畫效果的方法：

① 在res的anim文件夾下，創建一個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表示相對于父空間的位置

② 在Activity中使用AnimationUtils獲取Animation并進行設置：

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

也可以使用AnimationSet為一個控件添加多個動畫，或者在xml文件中添加多個動畫標簽，以下分別使用代碼和XML文件實現相同的效果：

代碼中實現：

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實現：

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中的代碼：

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定義了動畫變化的速率或規律，其具體的實現可以使用以下子類：

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.

這些Interpolator可以在代碼或XML文件中定義：

XML文件定義在set標簽里或每個動畫標簽

set標簽中定義：

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

每個動畫標簽中定義：

<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>

在代碼中設置：

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

或者分別為每個動畫設置：

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 準備4張圖片run1.png,run2.png,run3.png,run4.png分別放到res的三個drawable文件夾中
② 在res的drawable-ldpi目錄下創建一個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文件設置ImageView控件imageView的背景源，并獲取AnimationDrawable進行顯示動畫：

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

使用LayoutAnimationController設置ListView的動畫

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控件的樣式效果的方法：

① 在res的anim文件夾中創建一個list_anim.xml文件用于控制ListView控件的動畫：

<?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 創建一個布局文件item.xml用于設置ListView的item的樣式：

<?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中添加一個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 創建一個MainActivity繼承ListActivity，并在onCreate方法中添加如下代碼：

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);//通過Animation獲取LayoutAnimationController對ListView進行設置
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);

這樣，運行程序，顯示的ListView就會按照xml文件中預置的動畫效果顯示了。

也可以通過xml文件進行設置動畫：

① 在以上步驟的基礎之上，在res/anim文件夾下創建一個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添加如下屬性：

android:layoutAnimation="@anim/anim_layout"

這樣就在把MainActivity的onCreate()方法中的
//通過Animation獲取LayoutAnimationController對ListView進行設置
注釋后的代碼刪除了，直接使用xml進行動畫的控制。

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.

包含以下的三個方法：

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 可以為一個Button添加一個事件：

button.setOnClickListener(new TestAnimationListener());

② 接下來是編寫這個TestAnimationListener類，繼承AnimationListener，并覆蓋里面的三個方法：

//這里獲取控件組，R.id.layoutId為main.xml的整體布局標簽的id屬性值
ViewGroup viewGroup = (ViewGroup)findViewById(R.id.layoutId);private class RemoveAnimationListener implements AnimationListener{//該方法在淡出效果執行結束之后被調用@Overridepublic void onAnimationEnd(Animation animation) {//假設這里要在動畫執行完之后刪除一個TextViewviewGroup.removeView(textView);}@Overridepublic void onAnimationRepeat(Animation animation) {System.out.println("onAnimationRepeat");}@Overridepublic void onAnimationStart(Animation animation) {System.out.println("onAnimationStart");}}

③ 同樣的，在動畫效果中添加控件可以按照如下實現

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);

（特別說明：本文部分內容是在觀看marschen的Android視頻教程時做的筆記，感謝marschen推出的視頻教程，這里也推薦給大家：http://www.marschen.com/portal.php）

除了文章中有特別說明，均為IT宅原創文章，轉載請以鏈接形式注明出處。
本文鏈接：http://www.itzhai.com/android-animation-used-to-achieve-control-of-animation-effects-and-use-of-interpolator-and-animationlistener.html

關鍵字:?AlphaAnimation,?Android,?AnimationListener,?Interpolator,?RotateAnimation,?ScaleAnimation,?TranslateAnimation