Android——仿QQ聊天撒花特效

实现这样的效果，你要知道贝塞尔曲线，何谓贝塞尔曲线？其实就是曲线，嘿嘿，关于曲线的概念大家可以去

Android绘图机制（二）——自定义View绘制形, 圆形, 三角形, 扇形, 椭圆, 曲线,文字和图片的坐标讲解
中看下，我们这里就直接写了

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">

    </button>
</relativelayout>

2.Fllower

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 = ;
    /**
     * 动画间隔
     */
    private int delay = ;

    int[] ylocations = { -, -, -,  };

    /**
     * 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() *  / 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 = ;
    /**
     * 高度
     */
    private int height = ;

    /**
     * 曲线高度个数分割
     */
    private int quadCount = ;
    /**
     * 曲度
     */
    private float intensity = 0.2f;

    /**
     * 第一批个数
     */
    private int fllowerCount = ;

    /**
     * 创建花
     */
    private void builderFollower(int count, List<fllower> fllowers) {

        int max = (int) (width *  / 4f);
        int min = (int) (width / 4f);
        Random random = new Random();
        for (int i = ; i < count; i++) {
            int s = random.nextInt(max) % (max - min + ) + min;
            Path path = new Path();
            CPoint CPoint = new CPoint(s, ylocations[random.nextInt()]);
            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() > ) {
            for (int j = ; j < points.size(); j++) {

                CPoint point = points.get(j);

                if (j == ) {
                    CPoint next = points.get(j + );
                    point.dx = ((next.x - point.x) * intensity);
                    point.dy = ((next.y - point.y) * intensity);
                } else if (j == points.size() - ) {
                    CPoint prev = points.get(j - );
                    point.dx = ((point.x - prev.x) * intensity);
                    point.dy = ((point.y - prev.y) * intensity);
                } else {
                    CPoint next = points.get(j + );
                    CPoint prev = points.get(j - );
                    point.dx = ((next.x - prev.x) * intensity);
                    point.dy = ((next.y - prev.y) * intensity);
                }

                // create the cubic-spline path
                if (j == ) {
                    path.moveTo(point.x, point.y);
                } else {
                    CPoint prev = points.get(j - );
                    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, , 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 = ; i < quadCount; i++) {
            if (i == ) {
                points.add(point);
            } else {
                CPoint tmp = new CPoint(, );
                if (random.nextInt() %  == ) {
                    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,
            , getResources().getDisplayMetrics());

    /**
     * @param canvas
     * @param fllowers
     */
    private void drawFllower(Canvas canvas, List<fllower> fllowers) {
        for (Fllower fllower : fllowers) {
            float[] pos = new float[];
            // 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[], pos[] - 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 * );
    }

    /**
     * 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

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();
            }
        });
    }
}