如何在iOS中显示钻石形状的图像？
如何在iOS中显示钻石形状的图像？
提问于 2016-07-08 07:17:35
原来的图像是这样的海，我是iOS的新手，我的要求是显示钻石形状的图像，为此，我遵循以下代码。我拿了一个UIView，ImageView是那个UIView的子视图。我得到的钻石形状，但形象是翻转。如何解决这个问题？
var tr: CGAffineTransform = CGAffineTransformIdentity
tr = CGAffineTransformScale(tr, 0.8, 1)
tr = CGAffineTransformRotate(tr, 0.7)
self.views.transform = tr回答 2
Stack Overflow用户
回答已采纳
发布于 2016-07-08 07:25:23
您可以使用UIBezierPath绘制形状
import UIKit
extension UIView
{
func addDiamondMaskToView()
{
let path = UIBezierPath()
path.moveToPoint(CGPoint(x: self.bounds.size.width / 2.0, y: 0))
path.addLineToPoint(CGPoint(x: self.bounds.size.width, y: self.bounds.size.height / 2.0))
path.addLineToPoint(CGPoint(x: self.bounds.size.width / 2.0, y: self.bounds.size.height))
path.addLineToPoint(CGPoint(x: 0, y: self.bounds.size.height / 2.0))
path.closePath()
let shapeLayer = CAShapeLayer()
shapeLayer.path = path.CGPath
shapeLayer.fillColor = UIColor.whiteColor().CGColor
shapeLayer.strokeColor = UIColor.clearColor().CGColor
self.layer.mask = shapeLayer
}
}您可以将该方法调用为
//suppose this is your imageview
let imgView = UIImageView(frame: CGRectMake(0, 0, 100, 200))
//then call the method as
imgView.addDiamondMaskToView()它对我来说很好，检查这些图像以供参考。
Stack Overflow用户
发布于 2016-07-08 14:21:11
由于您提供了图像，在分析之后，我可以得出结论，您需要做的是
- 向ImageView添加对角线掩码
- 将imageView内的图像旋转到一定的角度
假设图像旋转到45度，我提供的解决方案如下
import UIKit
extension UIView
{
func addDiamondMaskToView()
{
let path = UIBezierPath()
path.moveToPoint(CGPoint(x: self.bounds.size.width / 2.0, y: 0))
path.addLineToPoint(CGPoint(x: self.bounds.size.width, y: self.bounds.size.height / 2.0))
path.addLineToPoint(CGPoint(x: self.bounds.size.width / 2.0, y: self.bounds.size.height))
path.addLineToPoint(CGPoint(x: 0, y: self.bounds.size.height / 2.0))
path.closePath()
let shapeLayer = CAShapeLayer()
shapeLayer.path = path.CGPath
shapeLayer.fillColor = UIColor.whiteColor().CGColor
shapeLayer.strokeColor = UIColor.clearColor().CGColor
self.layer.mask = shapeLayer
}
}
extension UIImageView
{
func addDiamondWithSomeAngle(angleInDegrees degrees : CGFloat)
{
self.addDiamondMaskToView()
self.image = self.image?.imageRotatedByDegrees(degrees, flip: false)
}
}
extension UIImage {
public func imageRotatedByDegrees(degrees: CGFloat, flip: Bool) -> UIImage
{
let degreesToRadians: (CGFloat) -> CGFloat = {
return $0 / 180.0 * CGFloat(M_PI)
}
let rotatedViewBox = UIView(frame: CGRect(origin: CGPointZero, size: size))
let t = CGAffineTransformMakeRotation(degreesToRadians(degrees));
rotatedViewBox.transform = t
let rotatedSize = rotatedViewBox.frame.size
UIGraphicsBeginImageContext(rotatedSize)
let bitmap = UIGraphicsGetCurrentContext()
CGContextTranslateCTM(bitmap, rotatedSize.width / 2.0, rotatedSize.height / 2.0);
CGContextRotateCTM(bitmap, degreesToRadians(degrees));
var yFlip: CGFloat
if(flip){
yFlip = CGFloat(-1.0)
} else {
yFlip = CGFloat(1.0)
}
CGContextScaleCTM(bitmap, yFlip, -1.0)
CGContextDrawImage(bitmap, CGRectMake(-size.width / 2, -size.height / 2, size.width, size.height), CGImage)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
}您需要将该方法调用为
imageView.addDiamondWithSomeAngle(angleInDegrees: 45)输出如下
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/38260945
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