王學崗高級UI6——————貝塞爾曲線

第一，貝塞爾曲線

先看一篇大神的文章

第二，Path的使用，附錄一篇文章

path可以理解爲路徑，它的主要作用是繪製直線，曲線，或者其它的一些幾何圖形。也可以用於繪製文字。聯想canvas.draw()方法，path也是類似的功能。只是canvas比較簡單，path繪製出來的圖形會更加的複雜。比如我們要繪製五角星，用canvas就很困難了，但是path實現起來卻可以很簡單。
看下代碼，繪製兩個簡單的圓

package com.example.beisaier;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;

/**
 * @author writing
 * @time 2019/12/18 12:34
 * @note
 */
public class PathView extends View {

    private Path path1;
    private Path path2;
    private Paint paint;

    public PathView(Context context) {
        super(context);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        intit();
    }

    private void intit() {
        path1 = new Path();
        path2 = new Path();
        paint = new Paint();
        paint.setColor(Color.RED);
        paint.setStrokeWidth(4);
        paint.setStyle(Paint.Style.STROKE);
    }

    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        /**
         * Path.Direction
         * Path.Direction.CCW 逆時針
         * Path.Direction.CW 順時針
         */
        path1.addCircle(200,200,150, Path.Direction.CCW);
        path1.addCircle(300,300,150, Path.Direction.CW);

        canvas.drawPath(path1,paint);
        canvas.drawPath(path2,paint);
    }
}

效果圖

繪製0.x圓

package com.example.beisaier;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;

/**
 * @author writing
 * @time 2019/12/18 12:34
 * @note
 */
public class PathView extends View {

    private Path path1;
    private Path path2;
    private Path path3;
    private Paint paint;

    public PathView(Context context) {
        super(context);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        intit();
    }

    private void intit() {
        path1 = new Path();
        path2 = new Path();
        path3 = new Path();
        paint = new Paint();
        paint.setColor(Color.RED);
        paint.setStrokeWidth(4);
        paint.setStyle(Paint.Style.STROKE);
    }


    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        /**
         * Path.Direction
         * Path.Direction.CCW 逆時針
         * Path.Direction.CW 順時針
         */
         //半圓
        path1.addArc(200,200,500,500,0,90);
        path2.addArc(200,600,500,900,0,-90);
        canvas.drawPath(path1,paint);
        canvas.drawPath(path2,paint);
        paint.setStyle(Paint.Style.FILL);
        path3.addArc(200,900,500,1200,0,-90);
        canvas.drawPath(path3,paint);
    }
}

package com.example.beisaier;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;

/**
 * @author writing
 * @time 2019/12/18 12:34
 * @note
 */
public class PathView extends View {

    private Path path1;
    private Path path2;
    private Path path3;
    private Paint paint;

    public PathView(Context context) {
        super(context);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        intit();
    }

    private void intit() {
        path1 = new Path();
        path2 = new Path();
        path3 = new Path();
        paint = new Paint();
        paint.setColor(Color.RED);
        paint.setStrokeWidth(4);
        paint.setStyle(Paint.Style.STROKE);
    }


    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        /**
         * Path.Direction
         * Path.Direction.CCW 逆時針
         * Path.Direction.CW 順時針
         */
         //0.x橢圓,橢圓的一部分
        path1.arcTo(200, 200, 300, 300, 0, 90, true);
        //橢圓
        path1.addOval(300, 300, 400, 450, Path.Direction.CW);
        //矩形
        path1.addRect(100, 400, 300, 500, Path.Direction.CW);
        //圓角矩形
        path1.addRoundRect(100, 600, 300, 700, 20, 40, Path.Direction.CW);
        canvas.drawPath(path1, paint);
    }
}

繪製更加複雜的圖案

package com.example.beisaier;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;

/**
 * @author writing
 * @time 2019/12/18 12:34
 * @note
 */
public class PathView extends View {

    private Path path1;
    private Path path2;
    private Paint paint;

    public PathView(Context context) {
        super(context);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        intit();
    }

    public PathView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        intit();
    }

    private void intit() {
        path1 = new Path();
        path2 = new Path();
        paint = new Paint();
        paint.setColor(Color.RED);
        paint.setStrokeWidth(4);
        paint.setStyle(Paint.Style.STROKE);
    }


    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
                /**
         * Path.Direction繪製方向
         * Path.Direction.CCW   逆時針
         * Path.Direction.CW  順時針
         */
        path1.addCircle(200, 200, 100, Path.Direction.CW); //繪製圓
        path2.addCircle(300, 300, 100, Path.Direction.CW);
        /**
         * Path.op對兩個Path進行布爾運算(即取交集、並集等操作)
         * Path.Op.DIFFERENCE 減去path1中path1與path2都存在的部分;
         * path1 = (path1 - path1 ∩ path2)
         * Path.Op.INTERSECT 保留path1與path2共同的部分;
         * path1 = path1 ∩ path2
         * Path.Op.UNION 取path1與path2的並集;
         * path1 = path1 ∪ path2
         * Path.Op.REVERSE_DIFFERENCE 與DIFFERENCE剛好相反;
         * path1 = path2 - (path1 ∩ path2)
         * Path.Op.XOR 與INTERSECT剛好相反;
         * path1 = (path1 ∪ path2) - (path1 ∩ path2)
         */
        //五種情況
//        path1.op(path2,Path.Op.DIFFERENCE);
//        path1.op(path2,Path.Op.INTERSECT);
//        path1.op(path2,Path.Op.UNION);
//        path1.op(path2,Path.Op.XOR);
//        path1.op(path2,Path.Op.REVERSE_DIFFERENCE);
        canvas.drawPath(path1, paint);
        canvas.drawPath(path2, paint);
    }
}

path的其它一些API

     mPath1.moveTo(100, 100);//將路徑的繪製位置定在（x,y）的位置

        /**
         * 在前一個點的基礎上開始繪製，如果前面一個點是（x,y）,
         * rMoveTo(dx,dy)相當於moveTo(x+dx,y+dy),如果前面沒有調用moveTo，
         * 相當於從(dx,dy)開始繪製
         */
        mPath1.rMoveTo(100, 100);

不帶r的方法是基於原點的座標系(偏移量)， rXxx方法是基於當前點座標系(偏移量)
關於帶r的方法與不帶r方法的區別，詳細請看這篇文章

第三使用Path繪製貝塞爾曲線

path只可以繪製2、3階貝塞爾曲線。
繪製2階貝塞爾曲線

   path1.moveTo(100,100);
        path1.quadTo(400,200,10,500);
        canvas.drawPath(path1,paint);

繪製3階貝塞爾曲線

mPath1.moveTo(100, 100);
        mPath1.cubicTo(400, 200,10, 500,300, 700);
        canvas.drawPath(mPath1, mPaint);

第四繪製n階貝塞爾曲線

package com.example.beisaier;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PointF;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

import androidx.annotation.Nullable;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

/**
 * @author writing
 * @time 2019/12/20 14:44
 * @note
 */
public class BezierView extends View {

    private Paint mPaint;
    private Paint mLinePointPaint;
    private Path mPath;
    private List<PointF> mControlPoints;

    public BezierView(Context context) {
        super(context);
        init();
    }

    public BezierView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public BezierView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        //繪製貝塞爾曲線的畫筆
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setStrokeWidth(10);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setColor(Color.BLACK);
        //繪製點的畫筆
        mLinePointPaint = new Paint();
        mLinePointPaint.setAntiAlias(true);
        mLinePointPaint.setStrokeWidth(10);
        mLinePointPaint.setStyle(Paint.Style.STROKE);
        mLinePointPaint.setColor(Color.RED);
        //貝塞爾曲線路徑
        mPath = new Path();
        //控制點集合(包含數據點)
        mControlPoints = new ArrayList<>();

        //隨機生成控制點,我們這裏繪製的是四階貝塞爾曲線，
        // 如果大家想繪製更高階的貝塞爾曲線，修改循環的次數就可以

        Random random = new Random();
        for (int i = 0; i < 5; i++) {
            //產生200-1000的隨機數
            int x = random.nextInt(800) + 200;
            int y = random.nextInt(800) + 200;
            Log.i("zhang_xin", "隨機數x:" + x + ",隨機數y:" + y);
            PointF pointF = new PointF(x, y);
            mControlPoints.add(pointF);
        }

        //如果這裏大家不想用隨機數生成點，可以自己創建點
//        PointF pointF0 = new PointF(200, 200);
//        PointF pointF1 = new PointF(400, 500);
//        PointF pointF2 = new PointF(600, 650);
//        PointF pointF3 = new PointF(800, 500);
//        PointF pointF4 = new PointF(1000, 150);
//        mControlPoints.add(pointF0);
//        mControlPoints.add(pointF1);
//        mControlPoints.add(pointF2);
//        mControlPoints.add(pointF3);
//        mControlPoints.add(pointF4);


    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //繪製起始點、終止點、控制點以及各點的連線
        int size = mControlPoints.size();
        PointF pointF;
        for (int i = 0; i < size; i++) {
            pointF = mControlPoints.get(i);
            if (i > 0) {
                mLinePointPaint.setColor(Color.GREEN);
                canvas.drawLine(mControlPoints.get(i - 1).x, mControlPoints.get(i - 1).y, pointF.x, pointF.y, mLinePointPaint);
            }
            //起點終點換顏色
            if (i == 0) {
                mLinePointPaint.setColor(Color.BLUE);
            } else if (i == size - 1) {
                mLinePointPaint.setColor(Color.BLUE);
            }
            canvas.drawCircle(pointF.x, pointF.y, 20, mLinePointPaint);
        }
        //曲線連接
        buildBezierPoints();

        canvas.drawPath(mPath,mPaint);
    }

    private void buildBezierPoints() {
        mPath.reset();
        ArrayList<PointF> pointFS = new ArrayList<>();
        int order = mControlPoints.size()-1;//貝塞爾的階數
        //份數，表示一條曲線繪製多少個點，我們這裏設置爲1000
        float delta = 1.0f / 1000;
        //for循環，求出每一個點
        for (float t = 0; t<=1;t=t+delta) {
            //bezier點集
            PointF pointF = new PointF(deCastelJau(order, 0, t, true), deCastelJau(order, 0, t, false));//計算在曲線上點位置
            pointFS.add(pointF);
            if (pointFS.size() == 1) {
                //如果是起點就移動到起點
                mPath.moveTo(pointFS.get(0).x, pointFS.get(0).y);
            } else {
                //不是起點就連接起來
                mPath.lineTo(pointF.x, pointF.y);
            }
        }
    }
    /**
     * p(i,j) =  (1-t) * p(i-1,j)  +  t * p(i-1,j+1);
     *
     * @param i          階數
     * @param j          控制點
     * @param t          時間，比值
     * @param calculateX 計算哪個座標值 true=x
     * @return
     */
    private float deCastelJau(int i, int j, float t, boolean calculateX) {

        if (i == 1) {
            //一階曲線
            return calculateX ? (1 - t) * mControlPoints.get(j).x + t * mControlPoints.get(j + 1).x :
                    (1 - t) * mControlPoints.get(j).y + t * mControlPoints.get(j + 1).y;
        } else {
            //遞歸降階
            return (1 - t) * deCastelJau(i - 1, j, t, calculateX) + t * deCastelJau(i - 1, j + 1, t, calculateX);
        }
    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            init();
            invalidate();
        }
        return super.onTouchEvent(event);
    }
}

繪製仿QQ氣泡

package com.dn_alan.myapplication;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.PointFEvaluator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PointF;
import android.graphics.Rect;
import android.os.Build;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.LinearInterpolator;
import android.view.animation.OvershootInterpolator;

import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;

/**
 * QQ氣泡效果
 */
public class DragBubbleView extends View {

    /**
     * 氣泡默認狀態--靜止
     */
    private final int BUBBLE_STATE_DEFAUL = 0;
    /**
     * 氣泡相連
     */
    private final int BUBBLE_STATE_CONNECT = 1;
    /**
     * 氣泡分離
     */
    private final int BUBBLE_STATE_APART = 2;
    /**
     * 氣泡消失
     */
    private final int BUBBLE_STATE_DISMISS = 3;

    /**
     * 氣泡半徑
     */
    private float mBubbleRadius;
    /**
     * 氣泡顏色
     */
    private int mBubbleColor;
    /**
     * 氣泡消息文字
     */
    private String mTextStr;
    /**
     * 氣泡消息文字顏色
     */
    private int mTextColor;
    /**
     * 氣泡消息文字大小
     */
    private float mTextSize;
    /**
     * 不動氣泡的半徑
     */
    private float mBubStillRadius;
    /**
     * 可動氣泡的半徑
     */
    private float mBubMoveableRadius;
    /**
     * 不動氣泡的圓心
     */
    private PointF mBubStillCenter;
    /**
     * 可動氣泡的圓心
     */
    private PointF mBubMoveableCenter;
    /**
     * 氣泡的畫筆
     */
    private Paint mBubblePaint;
    /**
     * 貝塞爾曲線path
     */
    private Path mBezierPath;

    private Paint mTextPaint;

    //文本繪製區域
    private Rect mTextRect;

    private Paint mBurstPaint;

    //爆炸繪製區域
    private Rect mBurstRect;

    /**
     * 氣泡狀態標誌
     */
    private int mBubbleState = BUBBLE_STATE_DEFAUL;
    /**
     * 兩氣泡圓心距離
     */
    private float mDist;
    /**
     * 氣泡相連狀態最大圓心距離
     */
    private float mMaxDist;
    /**
     * 手指觸摸偏移量
     */
    private final float MOVE_OFFSET;

    /**
     *  氣泡爆炸的bitmap數組
     */
    private Bitmap[] mBurstBitmapsArray;
    /**
     * 是否在執行氣泡爆炸動畫
     */
    private boolean mIsBurstAnimStart = false;

    /**
     * 當前氣泡爆炸圖片index
     */
    private int mCurDrawableIndex;

    /**
     *  氣泡爆炸的圖片id數組
     */
    private int[] mBurstDrawablesArray = {R.drawable.burst_1, R.drawable.burst_2
            , R.drawable.burst_3, R.drawable.burst_4, R.drawable.burst_5};

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public DragBubbleView(Context context) {
        this(context,null);

    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public DragBubbleView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs,0);

    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public DragBubbleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr,0
        );

    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public DragBubbleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        //獲取 XML layout中的屬性值
        TypedArray array = context.obtainStyledAttributes(attrs,R.styleable.DragBubbleView,defStyleAttr,0);
        mBubbleRadius = array.getDimension(R.styleable.DragBubbleView_bubble_radius,mBubbleRadius);
        mBubbleColor = array.getColor(R.styleable.DragBubbleView_bubble_color, Color.RED);
        mTextStr = array.getString(R.styleable.DragBubbleView_bubble_text);
        mTextSize = array.getDimension(R.styleable.DragBubbleView_bubble_textSize,mTextSize);
        mTextColor = array.getColor(R.styleable.DragBubbleView_bubble_textColor, Color.WHITE);
        //回收TypedArray
        array.recycle();

        mBubStillRadius = mBubbleRadius;
        mBubMoveableRadius = mBubStillRadius;
        mMaxDist = 8 * mBubbleRadius;

        MOVE_OFFSET = mMaxDist / 4;

        //抗鋸齒
        mBubblePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mBubblePaint.setColor(mBubbleColor);
        mBubblePaint.setStyle(Paint.Style.FILL);
        mBezierPath = new Path();

        //文本畫筆
        mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mTextPaint.setColor(mTextColor);
        mTextPaint.setTextSize(mTextSize);
        mTextRect = new Rect();

        //爆炸畫筆
        mBurstPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mBurstPaint.setFilterBitmap(true);
        mBurstRect = new Rect();
        mBurstBitmapsArray = new Bitmap[mBurstDrawablesArray.length];
        for (int i = 0; i < mBurstDrawablesArray.length; i++) {
            //將氣泡爆炸的drawable轉爲bitmap
            Bitmap bitmap = BitmapFactory.decodeResource(getResources(), mBurstDrawablesArray[i]);
            mBurstBitmapsArray[i] = bitmap;
        }
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        initView(w,h);
    }

    /**
     * 初始化氣泡位置
     * @param w
     * @param h
     */
    private void initView(int w, int h) {

        //設置兩氣泡圓心初始座標
        if(mBubStillCenter == null){
            mBubStillCenter = new PointF(w / 2,h / 2);
        }else{
            mBubStillCenter.set(w / 2,h / 2);
        }

        if(mBubMoveableCenter == null){
            mBubMoveableCenter = new PointF(w / 2,h / 2);
        }else{
            mBubMoveableCenter.set(w / 2,h / 2);
        }
        mBubbleState = BUBBLE_STATE_DEFAUL;
    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN:
            {
                if(mBubbleState != BUBBLE_STATE_DISMISS){
//                    將所提供的參數求平方和後開平方根的結果。
                    mDist = (float) Math.hypot(event.getX() - mBubStillCenter.x,
                            event.getY() - mBubStillCenter.y);
                    if(mDist < mBubbleRadius + MOVE_OFFSET){
                        // 加上MOVE_OFFSET是爲了方便拖拽
                        mBubbleState = BUBBLE_STATE_CONNECT;
                    }else{
                        mBubbleState = BUBBLE_STATE_DEFAUL;
                    }

                }
            }
            break;

            case MotionEvent.ACTION_MOVE:
            {
                if(mBubbleState != BUBBLE_STATE_DEFAUL){
                    mBubMoveableCenter.x = event.getX();
                    mBubMoveableCenter.y = event.getY();
                    mDist = (float) Math.hypot(event.getX() - mBubStillCenter.x,
                            event.getY() - mBubStillCenter.y);
                    if(mBubbleState == BUBBLE_STATE_CONNECT){
                        // 減去MOVE_OFFSET是爲了讓不動氣泡半徑到一個較小值時就直接消失
                        // 或者說是進入分離狀態
                        if(mDist < mMaxDist - MOVE_OFFSET){

                            mBubStillRadius = mBubbleRadius - mDist / 8;
                        }else{
                            mBubbleState = BUBBLE_STATE_APART;
                        }
                    }
                    invalidate();
                }
            }
            break;

            case MotionEvent.ACTION_UP:
            {
                if(mBubbleState == BUBBLE_STATE_CONNECT){
                    startBubbleRestAnim();

                }else if(mBubbleState == BUBBLE_STATE_APART){
                    if(mDist < 2 * mBubbleRadius){
                        startBubbleRestAnim();
                    }else{
                        startBubbleBurstAnim();
                    }
                }
            }
            break;
        }
        return true;
    }

    private void startBubbleBurstAnim() {
        //氣泡改爲消失狀態
        mBubbleState = BUBBLE_STATE_DISMISS;
        mIsBurstAnimStart = true;
        //做一個int型屬性動畫，從0~mBurstDrawablesArray.length結束
        ValueAnimator anim = ValueAnimator.ofInt(0, mBurstDrawablesArray.length);
        anim.setInterpolator(new LinearInterpolator());
        anim.setDuration(500);
        anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                //設置當前繪製的爆炸圖片index
                mCurDrawableIndex = (int) animation.getAnimatedValue();
                invalidate();
            }
        });
        anim.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                //修改動畫執行標誌
                mIsBurstAnimStart = false;
            }
        });
        anim.start();

    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    private void startBubbleRestAnim() {
        ValueAnimator anim = ValueAnimator.ofObject(new PointFEvaluator(),
        new PointF(mBubMoveableCenter.x,mBubMoveableCenter.y),
        new PointF(mBubStillCenter.x,mBubStillCenter.y));

        anim.setDuration(200);
        anim.setInterpolator(new OvershootInterpolator(5f));
        anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                mBubMoveableCenter = (PointF) animation.getAnimatedValue();
                invalidate();
            }
        });
        anim.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                mBubbleState = BUBBLE_STATE_DEFAUL;
            }
        });
        anim.start();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        // 1、畫靜止狀態
        // 2、畫相連狀態
        // 3、畫分離狀態
        // 4、畫消失狀態---爆炸動畫

        // 1、畫拖拽的氣泡 和 文字,只要不是消失狀態都要繪製帶文字的圓
        if(mBubbleState != BUBBLE_STATE_DISMISS){
            //靜止狀態下移動的小圓(沒有文字的那個小圓圈)
            canvas.drawCircle(mBubMoveableCenter.x,mBubMoveableCenter.y,
                    mBubMoveableRadius,mBubblePaint);

            mTextPaint.getTextBounds(mTextStr,0,mTextStr.length(),mTextRect);

            canvas.drawText(mTextStr,mBubMoveableCenter.x - mTextRect.width() / 2,
                    mBubMoveableCenter.y + mTextRect.height() / 2,mTextPaint);
        }
        // 2、畫相連的氣泡狀態
        if(mBubbleState == BUBBLE_STATE_CONNECT)
        {
            // 1、畫靜止氣泡
            canvas.drawCircle(mBubStillCenter.x,mBubStillCenter.y,
                    mBubStillRadius,mBubblePaint);
            // 2、畫相連曲線
            // 計算控制點座標，兩個圓心的中點
            int iAnchorX = (int) ((mBubStillCenter.x + mBubMoveableCenter.x) / 2);
            int iAnchorY = (int) ((mBubStillCenter.y + mBubMoveableCenter.y) / 2);
            //  O1E/O1O2
            float cosTheta = (mBubMoveableCenter.x - mBubStillCenter.x) / mDist;
            // O2E/O1O2
            float sinTheta = (mBubMoveableCenter.y - mBubStillCenter.y) / mDist;
            //求出ABCD四個點的座標
            float iBubStillStartX = mBubStillCenter.x - mBubStillRadius * sinTheta;
            float iBubStillStartY = mBubStillCenter.y + mBubStillRadius * cosTheta;
            float iBubStillEndX = mBubStillCenter.x + mBubStillRadius * sinTheta;
            float iBubStillEndY = mBubStillCenter.y - mBubStillRadius * cosTheta;
            float iBubMoveableStartX = mBubMoveableCenter.x + mBubMoveableRadius * sinTheta;
            float iBubMoveableStartY = mBubMoveableCenter.y - mBubMoveableRadius * cosTheta;
            float iBubMoveableEndX = mBubMoveableCenter.x - mBubMoveableRadius * sinTheta;
            float iBubMoveableEndY = mBubMoveableCenter.y + mBubMoveableRadius * cosTheta;



            mBezierPath.reset();//清除Path中的內容, reset不保留內部數據結構(重置路徑)

            // 畫上半弧
            mBezierPath.moveTo(iBubStillStartX,iBubStillStartY);//將路徑的繪製位置定在（x,y）的位置

            mBezierPath.quadTo(iAnchorX,iAnchorY,iBubMoveableEndX,iBubMoveableEndY);//二階貝塞爾曲線
            // 畫下半弧
            mBezierPath.lineTo(iBubMoveableStartX,iBubMoveableStartY);//結束點或者下一次繪製直線路徑的開始點

            mBezierPath.quadTo(iAnchorX,iAnchorY,iBubStillEndX,iBubStillEndY);//二階貝塞爾曲線

            //連接第一個點連接到最後一個點，形成一個閉合區域
            mBezierPath.close();
            canvas.drawPath(mBezierPath,mBubblePaint);
        }

        // 3、畫消失狀態---爆炸動畫
        if(mIsBurstAnimStart){
            mBurstRect.set((int)(mBubMoveableCenter.x - mBubMoveableRadius),
                    (int)(mBubMoveableCenter.y - mBubMoveableRadius),
                    (int)(mBubMoveableCenter.x + mBubMoveableRadius),
                    (int)(mBubMoveableCenter.y + mBubMoveableRadius));

            canvas.drawBitmap(mBurstBitmapsArray[mCurDrawableIndex],null,
                    mBurstRect,mBubblePaint);
        }
    }

    public void reset() {
        initView(getWidth(),getHeight());

        invalidate();
    }
}

package com.dn_alan.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {
    private DragBubbleView dragBubbleView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        //qq氣泡
        setContentView(R.layout.activity_main);
        dragBubbleView = findViewById(R.id.drag_buddle_view);
    }

    public void reset(View view) {
        dragBubbleView.reset();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#666666">
    <!--android:clipChildren="false"-->
    <com.dn_alan.myapplication.DragBubbleView
        android:id="@+id/drag_buddle_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        app:bubble_text="30"
        app:bubble_textColor="#ffffff"
        app:bubble_textSize="12dp"
        app:bubble_radius="12dp"
        app:bubble_color="#ff0000"
        />

    <Button
        android:id="@+id/reset_btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="reset"
        android:layout_alignParentBottom="true"
        android:layout_margin="20dp"
        android:textColor="#666666"
        android:text="還原" />

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="DragBubbleView">
        <attr name="bubble_radius" format="dimension"/>
        <attr name="bubble_color" format="color"/>
        <attr name="bubble_text" format="string"/>
        <attr name="bubble_textSize" format="dimension"/>
        <attr name="bubble_textColor" format="color"/>
    </declare-styleable>
</resources>

看下效果