2023年7月14日发(作者：)

如何优雅地画出渐变曲线画贝塞尔曲线，通过四个点算出两个控制点，画出连接中间两个点的曲线- (void)addCurveWithPoint0:(CGPoint)point0 point1:(CGPoint)point1 point2:(CGPoint)point2 point3:(CGPoint)point3 path:(UIBezierPath*)path { CGFloat x0 = point0.x, y0 = point0.y; CGFloat x1 = point1.x, y1 = point1.y; CGFloat x2 = point2.x, y2 = point2.y; CGFloat x3 = point3.x, y3 = point3.y;

CGFloat smooth_value =0.6; CGFloat ctrl1_x; CGFloat ctrl1_y; CGFloat ctrl2_x; CGFloat ctrl2_y; CGFloat xc1 = (x0 + x1) /2.0; CGFloat yc1 = (y0 + y1) /2.0; CGFloat xc2 = (x1 + x2) /2.0; CGFloat yc2 = (y1 + y2) /2.0; CGFloat xc3 = (x2 + x3) /2.0; CGFloat yc3 = (y2 + y3) /2.0; CGFloat len1 = sqrt((x1-x0) * (x1-x0) + (y1-y0) * (y1-y0)); CGFloat len2 = sqrt((x2-x1) * (x2-x1) + (y2-y1) * (y2-y1)); CGFloat len3 = sqrt((x3-x2) * (x3-x2) + (y3-y2) * (y3-y2)); CGFloat k1 = len1 / (len1 + len2); CGFloat k2 = len2 / (len2 + len3); CGFloat xm1 = xc1 + (xc2 - xc1) * k1; CGFloat ym1 = yc1 + (yc2 - yc1) * k1; CGFloat xm2 = xc2 + (xc3 - xc2) * k2; CGFloat ym2 = yc2 + (yc3 - yc2) * k2; ctrl1_x = xm1 + (xc2 - xm1) * smooth_value + x1 - xm1; ctrl1_y = ym1 + (yc2 - ym1) * smooth_value + y1 - ym1; ctrl2_x = xm2 + (xc2 - xm2) * smooth_value + x2 - xm2; ctrl2_y = ym2 + (yc2 - ym2) * smooth_value + y2 - ym2; [path addCurveToPoint:CGPointMake(x2, y2) controlPoint1:CGPointMake(ctrl1_x, ctrl1_y) controlPoint2:CGPointMake(ctrl2_x, ctrl2_y)];}实现渐变的⽅法： CAShapeLayer *curevePathLayer = [CAShapeLayer layer]; lor = [[UIColor clearColor] CGColor]; Color = [lor CGColor]; = ; dth = 5.0; p = kCALineCapRound; in = kCALineCapRound;

[ addSublayer:curevePathLayer];

CAGradientLayer *gradientLayer = [CAGradientLayer layer]; = CGRectMake(0, 0, , );

NSMutableArray *gradientColors = [[NSMutableArray alloc] init]; [gradientColors en_addObject:(id)[[UIColor darkGrayColor] CGColor]]; [gradientColors en_addObject:(id)[[UIColor lightGrayColor] CGColor]];

[gradientLayer setColors:gradientColors]; [gradientLayer setStartPoint:CGPointMake(0, 0.5)]; [gradientLayer setEndPoint:CGPointMake(1, 0.5)]; [gradientLayer setMask:curevePathLayer]; [ addSublayer:gradientLayer];