Android圆形散开动画

川长思鸟来 2022-08-02 09:34 206阅读 0赞

# 1 先看效果 #

**![Center][]**

**主要就是五颗按钮向五个方向散开（我这里是按钮，也可以放成其它控件）。**

# 2 实现 #

2.1 Android动画知识

http://blog.csdn.net/guolin\_blog?viewmode=contents 请看这个博客，博主讲的非常详细。

2.2 直接上代码

希望代码是自解释的。

package com.example.animationbutton;
    
    import android.app.Activity;
    import android.content.Context;
    import android.graphics.PointF;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.view.WindowManager;
    import android.view.animation.AlphaAnimation;
    import android.view.animation.Animation;
    import android.view.animation.Animation.AnimationListener;
    import android.view.animation.LinearInterpolator;
    import android.widget.ImageView;
    import android.widget.RelativeLayout;
    
    import com.nineoldandroids.animation.AnimatorSet;
    import com.nineoldandroids.animation.ObjectAnimator;
    import com.nineoldandroids.animation.TypeEvaluator;
    import com.nineoldandroids.animation.ValueAnimator;
    import com.nineoldandroids.animation.ValueAnimator.AnimatorUpdateListener;
    
    public class MainActivity extends Activity {
    
    	/**
    	 * 头像。
    	 */
    	private ImageView imageview;
    	/**
    	 * 屏幕宽度。
    	 */
    	private int window_width;
    	/**
    	 * 屏幕高度。
    	 */
    	private int window_height;
    	/**
    	 * 圆型按钮的宽度。
    	 */
    	private int image_width;
    	/**
    	 * 五角星。
    	 */
    	private ImageView wujiaoxing;
    	/**
    	 * 星品。
    	 */
    	private ImageView shop;
    	/**
    	 * 粉丝圈。
    	 */
    	private ImageView fans;
    	/**
    	 * 星踪迹。
    	 */
    	private ImageView news;
    	/**
    	 * 星表情。
    	 */
    	private ImageView expression;
    	/**
    	 * 星动时刻。
    	 */
    	private ImageView trails;
    	/**
    	 * 星盟logo。
    	 */
    	private ImageView istar;
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		// 设置全屏。
    		// getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
    		// WindowManager.LayoutParams.FLAG_FULLSCREEN);
    		final View view = View.inflate(this, R.layout.activity_main, null);
    		setContentView(view);
    		AlphaAnimation aa = new AlphaAnimation(0.7f, 1.0f);
    		aa.setDuration(500);
    		view.startAnimation(aa);
    		aa.setAnimationListener(new AnimationListener() {
    			@Override
    			public void onAnimationEnd(Animation arg0) {
    				// ObjectAnimator fadeIn = ObjectAnimator.ofFloat(imageview,
    				// "alpha", 0f, 1f);
    				int startangle = 54;
    				int length = (int) ((window_width
    						/ (Math.sin(72 * Math.PI / 180)) - image_width) / 2 - image_width / 5);
    				ValueAnimator expressionanim = zhixian(expression, startangle,
    						length);
    				ValueAnimator trailsanim = zhixian(trails, startangle + 72,
    						length);
    				ValueAnimator newsanim = zhixian(news, startangle + (72 * 2),
    						length);
    				ValueAnimator shopanim = zhixian(shop, startangle + (72 * 3),
    						length);
    				ValueAnimator fansanim = zhixian(fans, startangle + (72 * 4),
    						length);
    				AnimatorSet animSet = new AnimatorSet();
    
    				ObjectAnimator fadeIn = ObjectAnimator.ofFloat(imageview,
    						"alpha", 0f, 1f);
    				ObjectAnimator fadeOut = ObjectAnimator.ofFloat(istar, "alpha",
    						1f, 0f);
    
    				animSet.playTogether(fadeIn, fadeOut, shopanim, fansanim,
    						newsanim, expressionanim, trailsanim);
    				animSet.setDuration(1000);
    				animSet.start();
    			}
    
    			@Override
    			public void onAnimationRepeat(Animation animation) {
    			}
    
    			@Override
    			public void onAnimationStart(Animation animation) {
    			}
    
    		});
    
    		WindowManager wm = (WindowManager) getBaseContext().getSystemService(
    				Context.WINDOW_SERVICE);
    		window_width = wm.getDefaultDisplay().getWidth();
    		window_height = wm.getDefaultDisplay().getHeight() - 20;
    		image_width = window_width / 4;
    
    		imageview = (ImageView) findViewById(R.id.head);
    		RelativeLayout.LayoutParams paras = new RelativeLayout.LayoutParams(
    				image_width, image_width);
    		paras.leftMargin = window_width / 2 - image_width / 2;
    		paras.topMargin = window_height / 2 - image_width / 2;
    		imageview.setLayoutParams(paras);
    
    		wujiaoxing = (ImageView) findViewById(R.id.wujiaoxing);
    		RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
    				RelativeLayout.LayoutParams.MATCH_PARENT,
    				RelativeLayout.LayoutParams.MATCH_PARENT); // , 1是可选写的
    		lp.setMargins(image_width * 5 / 8, 0, image_width * 5 / 8, 0);
    		wujiaoxing.setLayoutParams(lp);
    		initbuttons();
    	}
    
    	@Override
    	protected void onResume() {
    		// TODO Auto-generated method stub
    		super.onResume();
    
    	}
    
    	/**
    	 * 沿直线运动。
    	 * 
    	 * @param view
    	 *            要移动的对象。
    	 * @param direction
    	 *            方向 +1 正方形，-1 负方向。
    	 * @param length
    	 */
    	public ValueAnimator zhixian(final View view, final int angle,
    			final int length) {
    		ValueAnimator valueAnimator = new ValueAnimator();
    		valueAnimator.setObjectValues(new PointF(0, 0));
    		valueAnimator.setInterpolator(new LinearInterpolator());
    		valueAnimator.setEvaluator(new TypeEvaluator<PointF>() {
    			// fraction = t / duration
    			@Override
    			public PointF evaluate(float fraction, PointF startValue,
    					PointF endValue) {
    				Log.v("znz", "znz ---> " + fraction);
    				PointF point = new PointF();
    				point.x = (float) (fraction * length * Math.cos(angle * Math.PI
    						/ 180));
    				point.y = (float) (fraction * length * Math.sin(angle * Math.PI
    						/ 180));
    				return point;
    			}
    		});
    		valueAnimator.addUpdateListener(new AnimatorUpdateListener() {
    			@Override
    			public void onAnimationUpdate(ValueAnimator animation) {
    				PointF point = (PointF) animation.getAnimatedValue();
    				RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
    						image_width, image_width);
    				params.leftMargin = (int) point.x
    						+ (window_width / 2 - image_width / 2); // Your
    																// coordinate
    				params.topMargin = (int) point.y
    						+ (window_height / 2 - image_width / 2); // Your Y
    																	// coordinate
    				Log.v("znz", "point.x ---> " + point.x);
    				Log.v("znz", "point.y ---> " + point.y);
    				view.setLayoutParams(params);
    			}
    		});
    		return valueAnimator;
    	}
    
    	/**
    	 * 初始化五颗按钮。
    	 */
    	private void initbuttons() {
    		shop = (ImageView) findViewById(R.id.shop);
    		fans = (ImageView) findViewById(R.id.fans);
    		news = (ImageView) findViewById(R.id.news);
    		expression = (ImageView) findViewById(R.id.expression);
    		trails = (ImageView) findViewById(R.id.trails);
    		istar = (ImageView) findViewById(R.id.istartlogo);
    		RelativeLayout.LayoutParams paras = new RelativeLayout.LayoutParams(
    				image_width, image_width);
    		// Your coordinate
    		paras.leftMargin = window_width / 2 - image_width / 2;
    		// Your Y coordinate
    		paras.topMargin = window_height / 2 - image_width / 2;
    		shop.setLayoutParams(paras);
    		fans.setLayoutParams(paras);
    		news.setLayoutParams(paras);
    		expression.setLayoutParams(paras);
    		trails.setLayoutParams(paras);
    		istar.setLayoutParams(paras);
    	}
    }

2.3 项目下载

[http://download.csdn.net/detail/zhounanzhaode/8902237][http_download.csdn.net_detail_zhounanzhaode_8902237]

## 2[专栏][Link 1] ##

## [郭霖的专栏][Link 1] ##

[Center]: /images/20220731/b6ed7a7a8d084a4a947ce7d683ebc960.png
[http_download.csdn.net_detail_zhounanzhaode_8902237]: http://download.csdn.net/detail/zhounanzhaode/8902237
[Link 1]: http://blog.csdn.net/guolin_blog