圆形UIView与阴影？ [英] Rounded UIView with Shadow?

问题描述

所以使用这个链接：
如何我在UIView下绘制阴影？

此链接：
http://iphonedevelopment.blogspot.com/2008/11/creating-transparent-uiviews-rounded.html p>

我来了这个实现：

   - （void）drawRect CGRect）rect {
 
 CGContextRef context = UIGraphicsGetCurrentContext（）; 
 
 CGContextSaveGState（context）; 
 CGContextSetShadow（context，CGSizeMake（-15.0f，20.0f），5.0f）; 
 
 CGContextSetLineWidth（context，strokeWidth）; 
 CGContextSetStrokeColorWithColor（context，self.strokeColor.CGColor）; 
 CGContextSetFillColorWithColor（context，self.rectColor.CGColor）; 
 
 CGRect rrect = self.bounds; 
 
 CGFloat radius = cornerRadius; 
 CGFloat width = CGRectGetWidth（rrect）; 
 CGFloat height = CGRectGetHeight（rrect）; 
 
 
 //确保拐角半径不大于短边的一半
 if（radius> width / 2.0）
 radius = width / 2.0; 
 if（radius> height / 2.0）
 radius = height / 2.0; 
 
 CGFloat minx = CGRectGetMinX（rrect）; 
 CGFloat midx = CGRectGetMidX（rrect）; 
 CGFloat maxx = CGRectGetMaxX（rrect）; 
 CGFloat miny = CGRectGetMinY（rrect）; 
 CGFloat midy = CGRectGetMidY（rrect）; 
 CGFloat maxy = CGRectGetMaxY（rrect）; 
 CGContextMoveToPoint（context，minx，midy）; 
 CGContextAddArcToPoint（context，minx，miny，midx，miny，radius）; 
 CGContextAddArcToPoint（context，maxx，miny，maxx，midy，radius）; 
 CGContextAddArcToPoint（context，maxx，maxy，midx，maxy，radius）; 
 CGContextAddArcToPoint（context，minx，maxy，minx，midy，radius）; 
 CGContextClosePath（context）; 
 CGContextDrawPath（context，kCGPathFillStroke）; 
 
 CGContextRestoreGState（context）; 
 
} 
  

但是当它绘制时，阴影被剪切到边界的视图。我尝试设置self.clipsToBounds = NO，但这不影响问题。

解决方案

如何使用Quartz绘制阴影核心？像：

  view.layer.shadowColor = [UIColor blackColor] .CGColor; 
 view.layer.shadowOffset = CGSizeMake（0，0）; 
 view.layer.shadowRadius = 4; 
 view.layer.shadowOpacity = 1; 
 view.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect：view.frame cornerRadius：11] .CGPath; // make sure you set that for better performance 
  

So using this link: How do I draw a shadow under a UIView?

And this link: http://iphonedevelopment.blogspot.com/2008/11/creating-transparent-uiviews-rounded.html

I came upon this implementation:

- (void)drawRect:(CGRect)rect {

CGContextRef context = UIGraphicsGetCurrentContext();

CGContextSaveGState(context);
CGContextSetShadow(context, CGSizeMake(-15.0f, 20.0f), 5.0f);

CGContextSetLineWidth(context, strokeWidth);
CGContextSetStrokeColorWithColor(context, self.strokeColor.CGColor);
CGContextSetFillColorWithColor(context, self.rectColor.CGColor);

CGRect rrect = self.bounds;

CGFloat radius = cornerRadius;
CGFloat width = CGRectGetWidth(rrect);
CGFloat height = CGRectGetHeight(rrect);


// Make sure corner radius isn't larger than half the shorter side
if (radius > width/2.0)
    radius = width/2.0;
if (radius > height/2.0)
    radius = height/2.0;    

CGFloat minx = CGRectGetMinX(rrect);
CGFloat midx = CGRectGetMidX(rrect);
CGFloat maxx = CGRectGetMaxX(rrect);
CGFloat miny = CGRectGetMinY(rrect);
CGFloat midy = CGRectGetMidY(rrect);
CGFloat maxy = CGRectGetMaxY(rrect);
CGContextMoveToPoint(context, minx, midy);
CGContextAddArcToPoint(context, minx, miny, midx, miny, radius);
CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius);
CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius);
CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius);
CGContextClosePath(context);
CGContextDrawPath(context, kCGPathFillStroke);

CGContextRestoreGState(context);

}

However when it draws, the shadow is clipped to the bounds of the view. I have tried setting self.clipsToBounds = NO however this doesn't affect the problem.

解决方案

How about drawing the shadow using Quartz Core instead? Something like:

view.layer.shadowColor = [UIColor blackColor].CGColor;
view.layer.shadowOffset = CGSizeMake(0, 0);
view.layer.shadowRadius = 4;
view.layer.shadowOpacity = 1;
view.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect:view.frame cornerRadius:11].CGPath; // make sure you set that for better performance

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