Android自定义View——进度条动画

控件效果

原理：

控制代码

//更新进度值
val mHandler = object : Handler() {
        override fun handleMessage(msg: Message?) {
            progressView.setCurrentProgress(progress1.toFloat())
        }
    }

//开启动画，更新进度值
 private fun progressAdd() {
        isAnimate = true
        progress1 = 0
        Thread(Runnable {
            while (isAnimate) {
                Thread.sleep(random.nextInt(200).toLong())
                progress1 += 1
                mHandler.sendEmptyMessage(0)
            }
        }).start()
    }

	//停止动画
    private fun progressReduce() {
        isAnimate = false
    }

控件源码：

public class ProgressView extends View {

    //前景颜色
    private int FIRST_COLOR = 0xffFEA711; //  0xff00574B;//
    //背景颜色
    private int SECOND_COLOR = 0xffFBE39C;

    private int mSecondWidth;
    private int mFirstWidth;
    private int mHeight;
    private int mSecondRadius;
    private int mFirstRadius;
    private int progressPadding = 30;

    private float currentValue;
    private int maxProgress = 100;

    //画笔
    private Paint paint;
    private RectF rectF;
    private Bitmap leafBitmap;
    private int mLeafWidth;
    private int mLeafHeight;
    private List mLeafInfos;

    public ProgressView(Context context) {
        super(context, null);
    }

    public ProgressView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ProgressView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        paint = new Paint();
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(FIRST_COLOR);
        paint.setAntiAlias(true);

        rectF = new RectF();
        leafBitmap = BitmapFactory.decodeResource(context.getResources(), R.mipmap.icon_leaf);
        mLeafWidth = leafBitmap.getWidth();
        mLeafHeight = leafBitmap.getHeight();
        Log.e("zhen", " mLeafWidth: " + mLeafWidth + " mLeafHeight: " + mLeafHeight);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mHeight = h;
        //外围
        mSecondWidth = w;
        mSecondRadius = (int) ((mSecondWidth * 1f / 5) / 2);
        //内部进度条
        mFirstWidth = mSecondWidth - progressPadding - mSecondRadius;
        mFirstRadius = mSecondRadius - progressPadding;
        mLeafInfos = new LeafFactory(mFirstRadius - mLeafWidth, 6).generateLeafs();
        Log.e("zhen", " mSecondWidth: " + mSecondWidth + " mHeight: " + mHeight +
                " mSecondRadius: " + mSecondRadius + " mFirstWidth: " + mFirstWidth + " mFirstRadius: " + mFirstRadius);

    }

    public void setCurrentProgress(float currentProgress) {
        Log.e("zhen", "currentProgress: " + currentProgress);
        if (currentProgress > 100) return;
        currentValue = currentProgress / maxProgress * mFirstWidth;
        invalidate();
    }

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


        //画布移动
        canvas.translate(mSecondRadius, mHeight / 2);
        //画背景左半圆
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(SECOND_COLOR);
        rectF.left = -mSecondRadius;
        rectF.top = -mSecondRadius;
        rectF.right = mSecondRadius;
        rectF.bottom = mSecondRadius;
        canvas.drawArc(rectF, 90, 180, false, paint);
        //画背景右半圆
        rectF.left = mSecondWidth - 3 * mSecondRadius;
        rectF.top = -mSecondRadius;
        rectF.right = mSecondWidth - mSecondRadius;
        rectF.bottom = mSecondRadius;
        canvas.drawArc(rectF, -90, 180, false, paint);
        //画背景中间方形
        rectF.left = 0;
        rectF.top = -mSecondRadius;
        rectF.right = mSecondWidth - 2 * mSecondRadius;
        rectF.bottom = mSecondRadius;
        canvas.drawRect(rectF, paint);
        //绘制进度条半圆
        paint.setColor(FIRST_COLOR);
        float leftValue = (mFirstRadius - currentValue) > 0 ? (mFirstRadius - currentValue) : 0;
        float angel = (float) Math.toDegrees(Math.acos(leftValue / mFirstRadius));
        rectF.left = -mFirstRadius;
        rectF.top = -mFirstRadius;
        rectF.right = mFirstRadius;
        rectF.bottom = mFirstRadius;
        canvas.drawArc(rectF, 180 - angel, 2 * angel, false, paint);
        //绘制进度条方形
        if (currentValue >= mFirstRadius) {
            currentValue = currentValue > mFirstWidth ? mFirstWidth : currentValue;
            rectF.left = 0;
            rectF.top = -mFirstRadius;
            rectF.right = currentValue - mFirstRadius;
            rectF.bottom = mFirstRadius;
            canvas.drawRect(rectF, paint);
        }

        //落叶纷飞
        if (currentValue > 0 && currentValue < mFirstWidth) {
            long currentTime = System.currentTimeMillis();
            for (int i = 0; i < mLeafInfos.size(); i++) {
                Leaf leaf = mLeafInfos.get(i);
                int delay = (int) ((currentTime - leaf.startTime) % CIRCLE_TIME);
                leaf.x = mFirstWidth - mFirstRadius - delay * (mFirstWidth * 1f / CIRCLE_TIME);
                if (leaf.x + mFirstRadius + mLeafWidth < currentValue) continue;
                leaf.y = (float) (leaf.amplitude * Math.sin(2 * Math.PI / CIRCLE_TIME * delay + leaf.phaseOffeset));
                Log.e("zhen", "延时ms数" + delay + " 角速度： " + (2 * Math.PI / CIRCLE_TIME) + " leaf.x: " + leaf.x + " leaf.y: " + leaf.y);
                // 通过Matrix控制叶子旋转
                Matrix matrix = new Matrix();
                matrix.postTranslate(leaf.x, leaf.y);
                // 根据叶子旋转方向确定叶子旋转角度
                float rotate = leaf.rotateOrientation ? leaf.x % 360f : -leaf.x % 360;
                matrix.postRotate(rotate, leaf.x + mLeafWidth / 2, leaf.y + mLeafHeight / 2);
                Log.e("zhen", "落叶子旋转角度: " + rotate);
                canvas.drawBitmap(leafBitmap, matrix, paint);
            }
        }


        //绘制旋转风车
        paint.setColor(Color.WHITE);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(10);
        float x = mSecondWidth - 2 * mSecondRadius;
        float y = 0;
        canvas.drawCircle(x, y, mSecondRadius, paint);
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(0XFFFCD158);
        canvas.drawCircle(x, y, mSecondRadius - 5, paint);
    }

    @IntDef({Amplitude.SMALL, Amplitude.MIDDLE, Amplitude.LARGE})
    public @interface Amplitude {
        int SMALL = 0;
        int MIDDLE = 1;
        int LARGE = 2;
    }

    public static class Leaf {

        public static long CIRCLE_TIME = 3000; //一个周期所需要的时间

        //振幅大小
        private int amplitude;
        //初始相位偏移
        private int phaseOffeset;
        //旋转方向
        private boolean rotateOrientation;
        //延时时间
        private long startTime;

        //x位置取决于初始位置偏移
        private float x;
        //y位置取决于振幅，初始相位
        private float y;

        @Override
        public String toString() {
            return "Leaf{" +
                    "amplitude=" + amplitude +
                    ", phaseOffeset=" + phaseOffeset +
                    ", rotateOrientation=" + rotateOrientation +
                    ", startTime=" + startTime +
                    ", x=" + x +
                    ", y=" + y +
                    '}';
        }
    }

    public static class LeafFactory {

        private Random random = new Random();
        int randomValue;

        private int mHeight;
        private int mLeafSize;

        public LeafFactory(int mHeight, int mLeafSize) {
            this.mHeight = mHeight;
            this.mLeafSize = mLeafSize;
        }

        public List generateLeafs() {
            List mLeafsInfo = new ArrayList<>();
            for (int i = 0; i < mLeafSize; i++) {
                mLeafsInfo.add(generateLeaf());
            }
            return mLeafsInfo;
        }

        private Leaf generateLeaf() {
            Leaf leaf = new Leaf();
            randomValue = random.nextInt(3);
            switch (randomValue) {
                case Amplitude.SMALL:
                    leaf.amplitude = (int) (mHeight * 1f / 3);
                    break;
                case Amplitude.MIDDLE:
                    leaf.amplitude = (int) (mHeight * 2f / 3);
                    break;
                case Amplitude.LARGE:
                    leaf.amplitude = (int) (mHeight * 3f / 3);
                    break;
            }
            leaf.startTime = random.nextInt((int) CIRCLE_TIME);
            leaf.phaseOffeset = random.nextInt(8);
            leaf.rotateOrientation = random.nextBoolean();
            Log.e("zhen", "生成一个叶子：" + leaf);
            return leaf;
        }
    }
    
}