先看看效果图吧

实现这样的效果，你要知道贝塞尔曲线，何谓贝塞尔曲线？先在这里打个问号

下面就直接写了

1.activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" > //撒花的区域 <RelativeLayout android:id="@+id/rlt_animation_layout" android:layout_width="match_parent" android:layout_height="match_parent" > </RelativeLayout> <Button android:id="@+id/btn_start" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="23dp" android:text="开始撒花" /> </RelativeLayout>

2.Fllower

传参类

package com.lgl.test; import android.graphics.Bitmap; import android.graphics.Path; import java.io.Serializable; public class Fllower implements Serializable { private static final long serialVersionUID = 1L; private Bitmap image; private float x; private float y; private Path path; private float value; public Bitmap getResId() { return image; } public void setResId(Bitmap img) { this.image = img; } public float getX() { return x; } public void setX(float x) { this.x = x; } public float getY() { return y; } public void setY(float y) { this.y = y; } public Path getPath() { return path; } public void setPath(Path path) { this.path = path; } public float getValue() { return value; } public void setValue(float value) { this.value = value; } @Override public String toString() { return "Fllower [ x=" + x + ", y=" + y + ", path=" + path + ", value=" + value + "]"; } }

3.FllowerAnimation

动画类

package com.lgl.test; import java.util.ArrayList; import java.util.List; import java.util.Random; import android.animation.ObjectAnimator; import android.animation.ValueAnimator; import android.animation.ValueAnimator.AnimatorUpdateListener; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Path; import android.graphics.PathMeasure; import android.util.Log; import android.util.TypedValue; import android.view.View; import android.view.WindowManager; import android.view.animation.AccelerateInterpolator; /** * 撒花 用到的知识点： 1、android属性动画 2、Path路径绘制 3、贝塞尔曲线 */ public class FllowerAnimation extends View implements AnimatorUpdateListener { /** * 动画改变的属性值 */ private float phase1 = 0f; private float phase2 = 0f; private float phase3 = 0f; /** * 小球集合 */ private List<Fllower> fllowers1 = new ArrayList<Fllower>(); private List<Fllower> fllowers2 = new ArrayList<Fllower>(); private List<Fllower> fllowers3 = new ArrayList<Fllower>(); /** * 动画播放的时间 */ private int time = 4000; /** * 动画间隔 */ private int delay = 400; int[] ylocations = { -100, -50, -25, 0 }; /** * 资源ID */ // private int resId = R.drawable.fllower_love; public FllowerAnimation(Context context) { super(context); init(context); // this.resId = resId; } @SuppressWarnings("deprecation") private void init(Context context) { WindowManager wm = (WindowManager) context .getSystemService(Context.WINDOW_SERVICE); width = wm.getDefaultDisplay().getWidth(); height = (int) (wm.getDefaultDisplay().getHeight() * 3 / 2f); mPaint = new Paint(); mPaint.setAntiAlias(true); // mPaint.setStrokeWidth(2); // mPaint.setColor(Color.BLUE); // mPaint.setStyle(Style.STROKE); pathMeasure = new PathMeasure(); builderFollower(fllowerCount, fllowers1); builderFollower(fllowerCount, fllowers2); builderFollower(fllowerCount, fllowers3); } /** * 宽度 */ private int width = 0; /** * 高度 */ private int height = 0; /** * 曲线高度个数分割 */ private int quadCount = 10; /** * 曲度 */ private float intensity = 0.2f; /** * 第一批个数 */ private int fllowerCount = 4; /** * 创建花 */ private void builderFollower(int count, List<Fllower> fllowers) { int max = (int) (width * 3 / 4f); int min = (int) (width / 4f); Random random = new Random(); for (int i = 0; i < count; i++) { int s = random.nextInt(max) % (max - min + 1) + min; Path path = new Path(); CPoint CPoint = new CPoint(s, ylocations[random.nextInt(3)]); List<CPoint> points = builderPath(CPoint); drawFllowerPath(path, points); Fllower fllower = new Fllower(); fllower.setPath(path); Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.lift_flower); fllower.setResId(bitmap); fllowers.add(fllower); } } /** * 画曲线 * * @param path * @param points */ private void drawFllowerPath(Path path, List<CPoint> points) { if (points.size() > 1) { for (int j = 0; j < points.size(); j++) { CPoint point = points.get(j); if (j == 0) { CPoint next = points.get(j + 1); point.dx = ((next.x - point.x) * intensity); point.dy = ((next.y - point.y) * intensity); } else if (j == points.size() - 1) { CPoint prev = points.get(j - 1); point.dx = ((point.x - prev.x) * intensity); point.dy = ((point.y - prev.y) * intensity); } else { CPoint next = points.get(j + 1); CPoint prev = points.get(j - 1); point.dx = ((next.x - prev.x) * intensity); point.dy = ((next.y - prev.y) * intensity); } // create the cubic-spline path if (j == 0) { path.moveTo(point.x, point.y); } else { CPoint prev = points.get(j - 1); path.cubicTo(prev.x + prev.dx, (prev.y + prev.dy), point.x - point.dx, (point.y - point.dy), point.x, point.y); } } } } /** * 曲线摇摆的幅度 */ private int range = (int) TypedValue .applyDimension(TypedValue.COMPLEX_UNIT_DIP, 70, getResources() .getDisplayMetrics()); /** * 画路径 * * @param point * @return */ private List<CPoint> builderPath(CPoint point) { List<CPoint> points = new ArrayList<CPoint>(); Random random = new Random(); for (int i = 0; i < quadCount; i++) { if (i == 0) { points.add(point); } else { CPoint tmp = new CPoint(0, 0); if (random.nextInt(100) % 2 == 0) { tmp.x = point.x + random.nextInt(range); } else { tmp.x = point.x - random.nextInt(range); } tmp.y = (int) (height / (float) quadCount * i); points.add(tmp); } } return points; } /** * 画笔 */ private Paint mPaint; /** * 测量路径的坐标位置 */ private PathMeasure pathMeasure = null; @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); drawFllower(canvas, fllowers1); drawFllower(canvas, fllowers2); drawFllower(canvas, fllowers3); } /** * 高度往上偏移量,把开始点移出屏幕顶部 */ private float dy = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 40, getResources().getDisplayMetrics()); /** * @param canvas * @param fllowers */ private void drawFllower(Canvas canvas, List<Fllower> fllowers) { for (Fllower fllower : fllowers) { float[] pos = new float[2]; // canvas.drawPath(fllower.getPath(),mPaint); pathMeasure.setPath(fllower.getPath(), false); pathMeasure.getPosTan(height * fllower.getValue(), pos, null); // canvas.drawCircle(pos[0], pos[1], 10, mPaint); canvas.drawBitmap(fllower.getResId(), pos[0], pos[1] - dy, null); } } ObjectAnimator mAnimator1; ObjectAnimator mAnimator2; ObjectAnimator mAnimator3; public void startAnimation() { if (mAnimator1 != null && mAnimator1.isRunning()) { mAnimator1.cancel(); } mAnimator1 = ObjectAnimator.ofFloat(this, "phase1", 0f, 1f); mAnimator1.setDuration(time); mAnimator1.addUpdateListener(this); mAnimator1.start(); mAnimator1.setInterpolator(new AccelerateInterpolator(1f)); if (mAnimator2 != null && mAnimator2.isRunning()) { mAnimator2.cancel(); } mAnimator2 = ObjectAnimator.ofFloat(this, "phase2", 0f, 1f); mAnimator2.setDuration(time); mAnimator2.addUpdateListener(this); mAnimator2.start(); mAnimator2.setInterpolator(new AccelerateInterpolator(1f)); mAnimator2.setStartDelay(delay); if (mAnimator3 != null && mAnimator3.isRunning()) { mAnimator3.cancel(); } mAnimator3 = ObjectAnimator.ofFloat(this, "phase3", 0f, 1f); mAnimator3.setDuration(time); mAnimator3.addUpdateListener(this); mAnimator3.start(); mAnimator3.setInterpolator(new AccelerateInterpolator(1f)); mAnimator3.setStartDelay(delay * 2); } /** * 跟新小球的位置 * * @param value * @param fllowers */ private void updateValue(float value, List<Fllower> fllowers) { for (Fllower fllower : fllowers) { fllower.setValue(value); } } /** * 动画改变回调 */ @Override public void onAnimationUpdate(ValueAnimator arg0) { updateValue(getPhase1(), fllowers1); updateValue(getPhase2(), fllowers2); updateValue(getPhase3(), fllowers3); Log.i(tag, getPhase1() + ""); invalidate(); } public float getPhase1() { return phase1; } public void setPhase1(float phase1) { this.phase1 = phase1; } public float getPhase2() { return phase2; } public void setPhase2(float phase2) { this.phase2 = phase2; } public float getPhase3() { return phase3; } public void setPhase3(float phase3) { this.phase3 = phase3; } private String tag = this.getClass().getSimpleName(); private class CPoint { public float x = 0f; public float y = 0f; /** * x-axis distance */ public float dx = 0f; /** * y-axis distance */ public float dy = 0f; public CPoint(float x, float y) { this.x = x; this.y = y; } } }

4.MainActivity

接着就看我们使用

package com.lgl.test; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.RelativeLayout; public class MainActivity extends Activity { private Button btn_start; // 撒花特效 private RelativeLayout rlt_animation_layout; private FllowerAnimation fllowerAnimation; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 撒花初始化 rlt_animation_layout = (RelativeLayout) findViewById(R.id.rlt_animation_layout); rlt_animation_layout.setVisibility(View.VISIBLE); fllowerAnimation = new FllowerAnimation(this); RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams( RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT); fllowerAnimation.setLayoutParams(params); rlt_animation_layout.addView(fllowerAnimation); btn_start = (Button) findViewById(R.id.btn_start); btn_start.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 开始撒花 fllowerAnimation.startAnimation(); } }); } }

好，我们现在来看看效果

源码下砸：Android仿QQ聊天撒花特效

好的，你也赶快去试一下吧！大家可以制作类似的雪花飘落效果等，Try！