由来
很多人对ValueAnimator不熟悉，，其实ValueAnimator的功能是非常强大的。它按照设定的时间和规则，在Update方法中将value友from变化到to。说起来很简单~
动画原理
我们可以使用ValueAnimator，将其由一个值变化为另外一个值，然后根据值的变化，按照一定的规则，动态修改View的属性，比如View的位置、透明度、旋转角度、大小等，即可完成了动画的效果。Yeah，就是这么简单。
Show My Codepackage net.mobctrl.moveviews;import net.mobctrl.moveviews.valueanimator.R;import android.animation.AnimatorSet;import android.animation.ValueAnimator;import android.animation.ValueAnimator.AnimatorUpdateListener;import android.annotation.SuppressLint;import android.app.Activity;import android.os.Bundle;import android.view.MotionEvent;import android.view.View;import android.view.View.OnClickListener;import android.view.View.OnTouchListener;import android.view.animation.DecelerateInterpolator;import android.view.animation.LinearInterpolator;import android.widget.Button;import android.widget.ImageView;import android.widget.RelativeLayout;import android.widget.TextView;/** * * @author Zheng Haibo * @web * */@SuppressLint({ “ClickableViewAccessibility”, “NewApi” }){private ImageView ivMove;private RelativeLayout rlRoot;private TextView tvTips;private int topTitleHeight;private Button animatorBtn1;private Button animatorBtn2;private Button animatorBtn3;private Button animatorBtn4;private int width;private int height;(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);ivMove = (ImageView) findViewById(R.id.iv_move);rlRoot = (RelativeLayout) findViewById(R.id.rl_root);tvTips = (TextView) findViewById(R.id.tv_tips);animatorBtn1 = (Button) findViewById(R.id.btn_move_animator_1);animatorBtn2 = (Button) findViewById(R.id.btn_move_animator_2);animatorBtn3 = (Button) findViewById(R.id.btn_move_animator_3);animatorBtn4 = (Button) findViewById(R.id.btn_move_animator_4);animatorBtn1.setOnClickListener(animatorClickListener);animatorBtn2.setOnClickListener(animatorClickListener);animatorBtn3.setOnClickListener(animatorClickListener);animatorBtn4.setOnClickListener(animatorClickListener);rlRoot.setOnTouchListener(this);tvTips.setOnClickListener(new OnClickListener() {(View v) {}});}(View v, MotionEvent event) {switch (event.getAction()) {case MotionEvent.ACTION_DOWN:int[] locations = new int[2];tvTips.getLocationInWindow(locations);topTitleHeight = locations[1];break;case MotionEvent.ACTION_MOVE:moveViewByLayout(ivMove, (int) event.getRawX(),(int) event.getRawY());break;case MotionEvent.ACTION_UP:break;}return true;}/*** 修改view的位置** @param view* @param rawX* @param rawY*/(View view, int rawX, int rawY) {int left = rawX – ivMove.getWidth() / 2;int top = rawY – topTitleHeight – ivMove.getHeight() / 2;int width = left + view.getWidth();int height = top + view.getHeight();view.layout(left, top, width, height);}private OnClickListener animatorClickListener = new OnClickListener() {(View v) {switch (v.getId()) {case R.id.btn_move_animator_1:moveLinePath();break;case R.id.btn_move_animator_2:moveCirclePath();break;case R.id.btn_move_animator_3:rotateAndAlpha();break;case R.id.btn_move_animator_4:scaleAnimator();break;default:break;}}};/*** 按直线轨迹运动*/() {width = rlRoot.getWidth();height = rlRoot.getHeight();ValueAnimator xValue = ValueAnimator.ofInt(width / 10, width / 2);xValue.setDuration(1000);xValue.addUpdateListener(new AnimatorUpdateListener() {(ValueAnimator animation) {// 轨迹方程 y = 1.5*xint x = (Integer) animation.getAnimatedValue();int y = (int) (1.5f * x);System.out.println(“debug:(x,y) = ” + x + “,” + y);moveViewByLayout(ivMove, x, y);}});xValue.setInterpolator(new LinearInterpolator());xValue.start();}/*** 先放大后缩小*/() {final float scale = 0.6f;AnimatorSet scaleSet = new AnimatorSet();ValueAnimator valueAnimatorSmall = ValueAnimator.ofFloat(1.0f, scale);valueAnimatorSmall.setDuration(500);ValueAnimator valueAnimatorLarge = ValueAnimator.ofFloat(scale, 1.0f);valueAnimatorLarge.setDuration(500);valueAnimatorSmall.addUpdateListener(new AnimatorUpdateListener() {(ValueAnimator animation) {float scale = (Float) animation.getAnimatedValue();ivMove.setScaleX(scale);ivMove.setScaleY(scale);}});valueAnimatorLarge.addUpdateListener(new AnimatorUpdateListener() {(ValueAnimator animation) {float scale = (Float) animation.getAnimatedValue();ivMove.setScaleX(scale);ivMove.setScaleY(scale);}});scaleSet.play(valueAnimatorLarge).after(valueAnimatorSmall);scaleSet.start();}/*** 旋转的同时进行透明度变化*/() {ValueAnimator valueAnimator = ValueAnimator.ofInt(0, 360);valueAnimator.setDuration(1000);valueAnimator.addUpdateListener(new AnimatorUpdateListener() {(ValueAnimator animation) {int rotateValue = (Integer) animation.getAnimatedValue();ivMove.setRotation(rotateValue);float fractionValue = animation.getAnimatedFraction();ivMove.setAlpha(fractionValue);}});valueAnimator.setInterpolator(new DecelerateInterpolator());valueAnimator.start();}/*** 圆形运行*/() {width = rlRoot.getWidth();height = rlRoot.getHeight();final int R = width / 4;ValueAnimator tValue = ValueAnimator.ofFloat(0,(float) (2.0f * Math.PI));tValue.setDuration(1000);tValue.addUpdateListener(new AnimatorUpdateListener() {(ValueAnimator animation) {// 圆的参数方程 x = R*sin(t) y = R*cos(t)float t = (Float) animation.getAnimatedValue();int x = (int) (R * Math.sin(t) + width / 2);int y = (int) (R * Math.cos(t) + height / 2);System.out.println(“debug:(x,y) = ” + x + “,” + y);moveViewByLayout(ivMove, x, y);}});tValue.setInterpolator(new DecelerateInterpolator());tValue.start();}}* main.xml *==”match_parent”android:layout_height=”match_parent” ><TextView==”true”android:text=”move your finger on the screen,next activity -> click this” /><LinearLayout==”horizontal” ><Button==”Anim1″ /><Button==”Anim2″ /><Button==”Anim3″ /><Button==”Anim4″ /></LinearLayout><ImageView==>项目链接* GitHub *
https://github.com/nuptboyzhb/MoveViewValueAnimator
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