寻找我的问题的解决方案,我必须在环中填充颜色。 我可以用我的代码填充一个颜色,但是我遇到了一些问题
使用此代码,我无法找到如何在圆圈中填充所需的颜色数量,即20%,40%,70%等。
当我给出渐变色时,它不是如图所示。
我正在使用的代码:
int radius = 130;
CAShapeLayer *arc = [CAShapeLayer layer];
arc.path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(100,0) radius:radius startAngle:39.8 endAngle:19.9 clockwise:YES].CGPath;
arc.position = CGPointMake(CGRectGetMidX(self.frame)-radius,
CGRectGetMidY(self.frame)-radius);
arc.fillColor = [UIColor clearColor].CGColor;
arc.strokeColor = [UIColor redColor].CGColor;
arc.lineWidth = 25;
CABasicAnimation *drawAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
drawAnimation.duration = 5.0; // "animate over 10 seconds or so.."
drawAnimation.repeatCount = 1.0; // Animate only once..
drawAnimation.removedOnCompletion = NO; // Remain stroked after the animation..
drawAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
drawAnimation.toValue = [NSNumber numberWithFloat:100.0f];
drawAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[arc addAnimation:drawAnimation forKey:@"drawCircleAnimation"];
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
UIColor *gradientColor = [UIColor colorWithRed:0.51 green:0.0 blue:0.49 alpha:1.0];
NSArray *gradientColors = [NSArray arrayWithObjects:
(id)[UIColor blueColor].CGColor,
(id)gradientColor.CGColor,
(id)[UIColor redColor].CGColor, nil];
CGFloat gradientLocations[] = {0, 0.5, 1};
CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (CFArrayRef)gradientColors, gradientLocations);
gradientLayer.colors = (__bridge NSArray *)(gradient);
gradientLayer.startPoint = CGPointMake(0.0,0.7);
gradientLayer.endPoint = CGPointMake(1,-0.1);
[self.layer addSublayer:gradientLayer];
gradientLayer.mask = arc;
重要提示:颜色必须如图所示
我正在为这个问题寻找非常具体的答案。
感谢所有有时间调查此事的所有人。
答案 0 :(得分:5)
要使用颜色填充圆的数量,您必须在填充图层的顶部绘制轮廓并仅剪切填充的图层。
为了使渐变跟随圆,您必须将其划分为多个分段线性渐变。由于您提供的图形已经有一些带轮廓的线段,我们可以使用这些轮廓来隐藏任何不完整的连接不同的渐变。
我举了一个例子,如果你想更多地控制颜色,你可以为CircleGradientLayer
中的每个片段设置它们。通过设置progress
的{{1}}属性来控制绘制的进度。
如果你在这里看到我的答案,可以使用两个圆圈和一些线条来简化绘制轮廓:https://stackoverflow.com/a/24580817/3659846但是在编写此代码时,复制和粘贴速度更快;)
.h文件没什么特别的,只是插入编译器想要的内容,我只在这里发布.m:
CircleProgressView
CircleProgressView
CircleGradientLayer
@implementation CircleProgressView{
CircleGradientLayer *_gradientLayer;
CircleOutlineLayer *_outlineLayer;
}
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.backgroundColor = [UIColor clearColor];
int numSegments = 7;
CGFloat circleRadius = 130;
CGFloat circleWidth = 30;
NSDictionary *circleData = @{
@"numberOfSegments":@(numSegments),
@"circleRadius":@(circleRadius),
@"circleWidth":@(circleWidth)
};
_gradientLayer = [CircleGradientLayer layer];
_gradientLayer.contentsScale = 2;
_gradientLayer.frame = self.bounds;
[_gradientLayer setCircleData:circleData];
[_gradientLayer setNeedsDisplay];
[self.layer addSublayer:_gradientLayer];
_outlineLayer = [CircleOutlineLayer layer];
_outlineLayer.frame = self.bounds;
_outlineLayer.contentsScale = 2;
[_outlineLayer setCircleData:circleData];
[_outlineLayer setNeedsDisplay];
[self.layer addSublayer:_outlineLayer];
self.progress = 1;
}
return self;
}
- (void)setProgress:(CGFloat)progress{
_progress = MAX(0, MIN(1, progress));
_gradientLayer.progress = progress;
}
@end
CircleOutlineLayer
@implementation CircleGradientLayer{
int _numSegments;
CGFloat _circleRadius;
CGFloat _circleWidth;
CAShapeLayer *_maskLayer;
}
+(id)layer{
CircleGradientLayer *layer = [[CircleGradientLayer alloc] init];
return layer;
}
-(void)setCircleData:(NSDictionary*)data{
_numSegments = [data[@"numberOfSegments"] intValue];
_circleRadius = [data[@"circleRadius"] doubleValue];
_circleWidth = [data[@"circleWidth"] doubleValue];
[self createMask];
}
- (void)createMask{
_maskLayer = [CAShapeLayer layer];
_maskLayer.frame = self.bounds;
CGFloat angleStep = 2*M_PI/(_numSegments+1);
CGFloat startAngle = angleStep/2 + M_PI_2;
CGFloat endAngle = startAngle+_numSegments*angleStep+0.005; //add a bit that the outline is not clipped
_maskLayer.path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds)) radius:_circleRadius startAngle:startAngle endAngle:endAngle clockwise:YES].CGPath;
_maskLayer.fillColor = [UIColor clearColor].CGColor;
_maskLayer.strokeColor = [UIColor redColor].CGColor;
_maskLayer.lineWidth = 2*_circleWidth+2; //stroke is centered -> *2 to cover all
self.mask = _maskLayer;
}
- (void)setProgress:(CGFloat)progress{
_progress = MAX(0, MIN(1, progress));
_maskLayer.strokeEnd = _progress;
}
-(void)drawInContext:(CGContextRef)ctx{
// would get better gradient joints by not using antialias, but since they are hidden, it is not needed to adjust it
// CGContextSetAllowsAntialiasing(ctx, NO);
UIGraphicsPushContext(ctx);
//some values to adjust the circle
UIColor *startColor = [UIColor colorWithRed:1 green:0 blue:21/255. alpha:1];
UIColor *endColor = [UIColor colorWithRed:0 green:180/255. blue:35/255. alpha:1];
CGPoint centerPoint = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
//calculate startAngle and the increment between segements
CGFloat angleStep = 2*M_PI/(_numSegments+1);
CGFloat startAngle = angleStep/2 + M_PI_2;
//convert colors to hsv
CGFloat startHue,startSat,startBrightness,startAlpha;
CGFloat endHue,endSat,endBrightness,endAlpha;
[startColor getHue:&startHue saturation:&startSat brightness:&startBrightness alpha:&startAlpha];
[endColor getHue:&endHue saturation:&endSat brightness:&endBrightness alpha:&endAlpha];
if(endHue<startHue)
endHue+=1;
//draw the segments
for(int i=0;i<_numSegments;i++){
//calcualte segment startColor
CGFloat hue = startHue+((endHue-startHue)*i)/_numSegments;
if(hue>1)
hue-=1;
CGFloat brightness = startBrightness+((endBrightness-startBrightness)*i)/(_numSegments);
if(_numSegments==7){
//just increasing the brighness a bit to get more yellow like on your picture ;)
brightness = i>3?startBrightness+((endBrightness-startBrightness)*(i-4))/(_numSegments-4):startBrightness;
}
UIColor *fromColor = [UIColor colorWithHue:hue saturation:startSat+((endSat-startSat)*i)/_numSegments brightness:brightness alpha:startAlpha+((endAlpha-startAlpha)*i)/_numSegments];
//calculate segement endColor
hue = startHue+((endHue-startHue)*(i+1))/_numSegments;
if(hue>1)
hue-=1;
brightness = startBrightness+((endBrightness-startBrightness)*i)/(_numSegments);
if(_numSegments==7){
brightness = i>3?startBrightness+((endBrightness-startBrightness)*(i-3))/(_numSegments-4):startBrightness;
}
UIColor *toColor = [UIColor colorWithHue:hue saturation:startSat+((endSat-startSat)*(i+1))/_numSegments brightness:brightness alpha:startAlpha+((endAlpha-startAlpha)*(i+1))/_numSegments];
//actually draw the segment
[self drawSegmentAtCenter:centerPoint from:startAngle to:startAngle+angleStep radius:_circleRadius width:_circleWidth startColor:fromColor endColor:toColor];
startAngle+=angleStep;
}
//start clearing the inside
CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeClear);
UIBezierPath* innerPath = [UIBezierPath bezierPath];
[innerPath moveToPoint:centerPoint];
[innerPath addArcWithCenter:centerPoint radius:_circleRadius-_circleWidth-0.5 startAngle:0 endAngle:2*M_PI clockwise:YES];
[innerPath fill];
}
- (void)drawSegmentAtCenter:(CGPoint)center from:(CGFloat)startAngle to:(CGFloat)endAngle radius:(CGFloat)radius width:(CGFloat)width startColor:(UIColor *)startColor endColor:(UIColor*)endColor{
CGContextSaveGState(UIGraphicsGetCurrentContext());
//apply a clip arc for the gradient
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:center];
[path addArcWithCenter:center radius:radius startAngle:startAngle endAngle:endAngle clockwise:YES];
[path addClip];
//draw the gradient
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat locations[] = { 0.0, 1.0 };
NSArray *colors = @[(__bridge id) startColor.CGColor, (__bridge id) endColor.CGColor];
CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef) colors, locations);
CGPoint startPoint = CGPointMake(center.x-sinf(startAngle-M_PI_2)*radius, center.y+cosf(startAngle-M_PI_2)*radius);
CGPoint endPoint = CGPointMake(center.x-sinf(endAngle-M_PI_2)*radius, center.y+cosf(endAngle-M_PI_2)*radius);
CGContextDrawLinearGradient(UIGraphicsGetCurrentContext(), gradient, startPoint, endPoint, kCGGradientDrawsAfterEndLocation|kCGGradientDrawsBeforeStartLocation);
CGGradientRelease(gradient);
CGColorSpaceRelease(colorSpace);
CGContextRestoreGState(UIGraphicsGetCurrentContext());
}
@end