效果图:

1.自定义BPDashBoardView2

/**
 * 血压刻度仪表盘--单环双点
 */
public class BPDashBoardView2 extends View {
    private static final float START_ANGLE = 135f;
    private static final float MAX_ANGLE = 270f;
    private float centerX;
    private float centerY;
    private float width;
    private float height;
    private int lineWidth = dp2px(8); // 绘制圆环的线宽
    private int pointWidth = dp2px(2); // 绘制圆点线宽

    private SweepGradient sweepGradient;

    private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private Paint pointPaint1 = new Paint(Paint.ANTI_ALIAS_FLAG);
    private Paint pointPaint2 = new Paint(Paint.ANTI_ALIAS_FLAG);
    private float highProgress = 0;
    private float lowProgress = 0;

    private int[] colors = {
            Color.parseColor("#FF9C9C"),
            Color.parseColor("#FF9C9C"),//浅色
            Color.parseColor("#FF9C9C"),
            Color.parseColor("#F8A0A2"),
            Color.parseColor("#A1D1F8"),
            Color.parseColor("#59A2FF"),
            Color.parseColor("#3586FF"),
            Color.parseColor("#3586FF"),
            Color.parseColor("#3586FF"),//深色
    };

    public BPDashBoardView2(Context context) {
        this(context, null);
    }

    public BPDashBoardView2(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public BPDashBoardView2(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        paint.setColor(Color.GRAY);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeCap(Paint.Cap.ROUND);
        paint.setStrokeWidth(lineWidth);

        pointPaint1.setColor(Color.WHITE);
        pointPaint1.setStyle(Paint.Style.STROKE);
        pointPaint1.setStrokeWidth(pointWidth);

        pointPaint2.setColor(Color.WHITE);
        pointPaint2.setStyle(Paint.Style.STROKE);
        pointPaint2.setStrokeWidth(pointWidth);
    }

    private void setProgress1(float progress) {
        this.highProgress = progress;
        invalidate();
    }

    private void setProgress2(float progress) {
        this.lowProgress = progress;
        invalidate();
    }

    public void setBPProgress(float high,float low) {
        ObjectAnimator animator = ObjectAnimator.ofFloat(this, "progress1", 0, high);
        animator.setDuration(2000);
        animator.setInterpolator(new FastOutSlowInInterpolator());
        animator.start();

        ObjectAnimator animator2 = ObjectAnimator.ofFloat(this, "progress2", 0, low);
        animator2.setDuration(2000);
        animator2.setInterpolator(new FastOutSlowInInterpolator());
        animator2.start();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        width = getWidth();
        height = getHeight();
        centerX = width/ 2;
        centerY = height / 2;
        sweepGradient = new SweepGradient(centerX, centerY, colors, null);
        //改变开始渐变的角度(默认从右边开始画圆渐变,旋转90度就从下方开始画圆渐变,旋转之后更好设置颜色渐变值)
        Matrix matrix = new Matrix();
        matrix.setRotate(90, centerX, centerY);
        sweepGradient.setLocalMatrix(matrix);
        paint.setShader(sweepGradient);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 绘制环形
        drawArc(canvas);
        // 绘制末尾圆点
        drawPoint(canvas);
    }

    private void drawArc(Canvas canvas) {
        int padding = lineWidth + pointWidth;
        canvas.drawArc(padding, padding, width - padding, height - padding, START_ANGLE, MAX_ANGLE, false, paint);
    }

    private void drawPoint(Canvas canvas) {
        int padding = lineWidth + pointWidth;
        float[] highPos = getPos(highProgress, padding);
        float[] lowPos = getPos(lowProgress, padding);

        drawPoint(canvas, highPos, Color.parseColor("#3586FF"));
        drawPoint(canvas, lowPos, Color.parseColor("#FF9C9C"));
    }

    private float[] getPos(float progress, int padding) {
        float sweepAngle = MAX_ANGLE * progress / 100;
        Path path = new Path();
        path.addArc(padding, padding, width - padding, height - padding, START_ANGLE, sweepAngle);
        PathMeasure measure = new PathMeasure(path, false);
        float[] pos = new float[2];
        measure.getPosTan(measure.getLength() - 1, pos, null);
        return pos;
    }

    private void drawPoint(Canvas canvas, float[] pos, int color) {
        pointPaint1.setColor(color);
        pointPaint1.setStyle(Paint.Style.FILL);
        canvas.drawCircle(pos[0], pos[1], lineWidth - pointWidth, pointPaint1);

        pointPaint1.setColor(Color.WHITE);
        pointPaint1.setStyle(Paint.Style.STROKE);
        canvas.drawCircle(pos[0], pos[1], lineWidth - pointWidth, pointPaint1);
    }

    public  int dp2px(final float dpValue) {
        final float scale = Resources.getSystem().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }
}

2.布局中使用

            <com.hwd.flowfit.ui.widget.BPDashBoardView2
                android:id="@+id/bpChart"
                android:layout_width="130dp"
                android:layout_height="130dp"
                android:layout_marginStart="30dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

3.设置进度

bpChart.setBPProgress(30f, 55f)