Android:ValueAnimator的使用举例【android】

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 Code

package 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 http://www.mobctrl.net * */ @SuppressLint({ "ClickableViewAccessibility", "NewApi" }) public class MainActivity extends Activity implements OnTouchListener {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; @Override protected void onCreate(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() {@Override public void onClick(View v) {} }); }@Override public boolean onTouch(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 */ private void moveViewByLayout(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() {@Override public void onClick(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 */ protected void moveLinePath() { width = rlRoot.getWidth(); height = rlRoot.getHeight(); ValueAnimator xValue = https://www.it610.com/article/ValueAnimator.ofInt(width / 10, width / 2); xValue.setDuration(1000); xValue.addUpdateListener(new AnimatorUpdateListener() {@Override public void onAnimationUpdate(ValueAnimator animation) { // 轨迹方程 y = 1.5*x int 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 */ protected void scaleAnimator() { 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() {@Override public void onAnimationUpdate(ValueAnimator animation) { float scale = (Float) animation.getAnimatedValue(); ivMove.setScaleX(scale); ivMove.setScaleY(scale); } }); valueAnimatorLarge.addUpdateListener(new AnimatorUpdateListener() {@Override public void onAnimationUpdate(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 */ protected void rotateAndAlpha() {ValueAnimator valueAnimator = ValueAnimator.ofInt(0, 360); valueAnimator.setDuration(1000); valueAnimator.addUpdateListener(new AnimatorUpdateListener() {@Override public void onAnimationUpdate(ValueAnimator animation) { int rotateValue = https://www.it610.com/article/(Integer) animation.getAnimatedValue(); ivMove.setRotation(rotateValue); float fractionValue = animation.getAnimatedFraction(); ivMove.setAlpha(fractionValue); } }); valueAnimator.setInterpolator(new DecelerateInterpolator()); valueAnimator.start(); }/** * 圆形运行 */ protected void moveCirclePath() { 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() {@Override public void onAnimationUpdate(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(); } }