一手遮天 Android - Animation: 视图动画（View Animation）插值器（Interpolator）
示例如下:
/animation/AnimationDemo2.java
/**
* 视图动画（View Animation）插值器（Interpolator）
* 视图动画只是改变了 View 的视觉效果，而并没有改变 View 的属性（比如 left, top, right, bottom 之类的都是不变的）
* View Animation（视图动画）即 Tween Animation（补间动画）
* 视图动画支持插值器（用于计算不同时间点的动画结果的比例值），相当于 easing 动画，默认值是 LinearInterpolator 匀速变化
*
*
* BounceInterpolator - 动画结束前来回弹几下
*
* AccelerateInterpolator - 先慢后快
* 构造函数有一个 float factor 参数，用于指定运动的变化程度，默认值为 1
*
* DecelerateInterpolator - 先快后慢
* 构造函数有一个 float factor 参数，用于指定运动的变化程度，默认值为 1
*
* AccelerateDecelerateInterpolator - 始末慢，中间快
*
* LinearInterpolator - 匀速
*
* CycleInterpolator - 按正弦曲线来回运动
* 构造函数有一个 float cycles 参数，用于指定正弦的周期数，默认值为 1
*
* AnticipateInterpolator - 开始时垃一下
* 构造函数有一个 float tension 参数，用于指定拉力的程度，默认值为 1
*
* OvershootInterpolator - 结束前垃一下
* 构造函数有一个 float tension 参数，用于指定拉力的程度，默认值为 1
*
* AnticipateOvershootInterpolator - 开始结束都垃一下
* 构造函数有一个 float tension 参数，用于指定拉力的程度，默认值为 1
*
* AnimationUtils.loadInterpolator(Context context, int id) - 获取 xml 中定义的 Interpolator 对象
*
*
* 注：以上所有插值器都有一个 public float getInterpolation(float input) 方法，用于获取指定值（0 - 1 之间）的插值后的结果
*/
package com.webabcd.androiddemo.animation;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.view.animation.AnticipateInterpolator;
import android.view.animation.AnticipateOvershootInterpolator;
import android.view.animation.CycleInterpolator;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.LinearInterpolator;
import android.view.animation.OvershootInterpolator;
import android.widget.Button;
import android.widget.TextView;
import com.webabcd.androiddemo.R;
public class AnimationDemo2 extends AppCompatActivity {
private TextView _textView1;
private Button _button1;
private Button _button2;
private Button _button3;
private Button _button4;
private Button _button5;
private Button _button6;
private Button _button7;
private Button _button8;
private Button _button9;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_animation_animationdemo2);
_textView1 = findViewById(R.id.textView1);
_button1 = findViewById(R.id.button1);
_button2 = findViewById(R.id.button2);
_button3 = findViewById(R.id.button3);
_button4 = findViewById(R.id.button4);
_button5 = findViewById(R.id.button5);
_button6 = findViewById(R.id.button6);
_button7 = findViewById(R.id.button7);
_button8 = findViewById(R.id.button8);
_button9 = findViewById(R.id.button9);
sample();
}
private void sample() {
_button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// AnimationUtils.loadAnimation() - 从 xml 中加载 Animation
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
_textView1.startAnimation(animation);
}
});
_button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
// 设置动画的插值器（插值器来自资源文件）
animation.setInterpolator(AnimationDemo2.this, R.anim.accelerateinterpolator_animation_animationdemo2);
_textView1.startAnimation(animation);
}
});
_button3.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
// 实例化插值器
DecelerateInterpolator decelerateInterpolator = new DecelerateInterpolator(1.0f);
// 设置动画的插值器
animation.setInterpolator(decelerateInterpolator);
_textView1.startAnimation(animation);
}
});
_button4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
AccelerateDecelerateInterpolator accelerateDecelerateInterpolator = new AccelerateDecelerateInterpolator();
animation.setInterpolator(accelerateDecelerateInterpolator);
_textView1.startAnimation(animation);
}
});
_button5.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
LinearInterpolator linearInterpolator = new LinearInterpolator();
animation.setInterpolator(linearInterpolator);
_textView1.startAnimation(animation);
}
});
_button6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
CycleInterpolator cycleInterpolator = new CycleInterpolator(2f);
animation.setInterpolator(cycleInterpolator);
_textView1.startAnimation(animation);
}
});
_button7.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
AnticipateInterpolator anticipateInterpolator = new AnticipateInterpolator(1f);
animation.setInterpolator(anticipateInterpolator);
_textView1.startAnimation(animation);
}
});
_button8.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
OvershootInterpolator overshootInterpolator = new OvershootInterpolator(1f);
animation.setInterpolator(overshootInterpolator);
_textView1.startAnimation(animation);
}
});
_button9.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Animation animation = AnimationUtils.loadAnimation(AnimationDemo2.this, R.anim.translate_animationdemo2);
AnticipateOvershootInterpolator anticipateOvershootInterpolator = new AnticipateOvershootInterpolator(1f);
animation.setInterpolator(anticipateOvershootInterpolator);
_textView1.startAnimation(animation);
}
});
}
}
/layout/activity_animation_animationdemo2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
android:textColor="#FFFF0000" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="Bounce"/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="Accelerate"/>
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="Decelerate"/>
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="AccelerateDecelerate"/>
<Button
android:id="@+id/button5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="Linear"/>
<Button
android:id="@+id/button6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="Cycle"/>
<Button
android:id="@+id/button7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="Anticipate"/>
<Button
android:id="@+id/button8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="Overshoot"/>
<Button
android:id="@+id/button9"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAllCaps="false"
android:text="AnticipateOvershoot"/>
</LinearLayout>
/anim/translate_animationdemo2.xml
<!--
定义一个 translate 动画，并指定其 interpolator（关于各种 interpolator 的解释参见 animation/AnimationDemo2.java 中的说明）
本例指定了 interpolator="@android:anim/bounce_interpolator" 即使用内置的 bounce_interpolator 插值器
如果需要自己定义已有插值器的参数（参见 res/anim/accelerateinterpolator_animation_animationdemo2.xml），则类似这样设置即可 interpolator="@anim/accelerateinterpolator_animation_animationdemo2"
-->
<translate xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="2000"
android:fillAfter="true"
android:fillBefore="false"
android:fromXDelta="0%p"
android:interpolator="@android:anim/bounce_interpolator"
android:toXDelta="50%p">
</translate>
/anim/accelerateinterpolator_animation_animationdemo2.xml
<?xml version="1.0" encoding="utf-8"?>
<!--
自己定义已有插值器的参数
-->
<accelerateInterpolator
xmlns:android="http://schemas.android.com/apk/res/android"
android:factor="1">
</accelerateInterpolator>