Create a rectangle with just two rounded corners i

问题:

I need to create a rectangle that have just two rounded corners in swift (Objective C code also ok).

At the moment my code is creating two rectangles with

CGPathCreateWithRoundedRect(CGRectMake(0, 0, 30, 60), 5, 5, nil);

and

CGPathCreateWithRoundedRect(CGRectMake(0, 0, 30, 60), 0, 0, nil);

and merging them (to have two right angle corners and two rounded ones) but I am not happy with the code and I am pretty sure there should be much better ways to do it.

I am new to iOS and graphical development and swift.

回答1:

In Swift 2.3 you could do so by

let maskPath = UIBezierPath(roundedRect: anyView.bounds,
            byRoundingCorners: [.BottomLeft, .BottomRight],
            cornerRadii: CGSize(width: 10.0, height: 10.0))

let shape = CAShapeLayer()
shape.path = maskPath.CGPath
view.layer.mask = shape

---

In Objective-C you could use the UIBezierPath class method

bezierPathWithRoundedRect:byRoundingCorners:cornerRadii:

example implementation-

// set the corner radius to the specified corners of the passed container
- (void)setMaskTo:(UIView*)view byRoundingCorners:(UIRectCorner)corners
{
    UIBezierPath *rounded = [UIBezierPath bezierPathWithRoundedRect:view.bounds
                                                  byRoundingCorners:corners
                                                        cornerRadii:CGSizeMake(10.0, 10.0)];
    CAShapeLayer *shape = [[CAShapeLayer alloc] init];
    [shape setPath:rounded.CGPath];
    view.layer.mask = shape;
}

and call the above method as-

[self setMaskTo:anyView byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight];

回答2:

Here's a quick Swift 3 extension you can use to do rounding and optional borders.

Note: if you're using autolayout, you may need to call this in one of the view lifecycle callbacks like viewDidLayoutSubviews or layoutSubviews after the view has been constrained.

import UIKit

extension UIView {

    /**
     Rounds the given set of corners to the specified radius

     - parameter corners: Corners to round
     - parameter radius:  Radius to round to
     */
    func round(corners: UIRectCorner, radius: CGFloat) {
        _ = _round(corners: corners, radius: radius)
    }

    /**
     Rounds the given set of corners to the specified radius with a border

     - parameter corners:     Corners to round
     - parameter radius:      Radius to round to
     - parameter borderColor: The border color
     - parameter borderWidth: The border width
     */
    func round(corners: UIRectCorner, radius: CGFloat, borderColor: UIColor, borderWidth: CGFloat) {
        let mask = _round(corners: corners, radius: radius)
        addBorder(mask: mask, borderColor: borderColor, borderWidth: borderWidth)
    }

    /**
     Fully rounds an autolayout view (e.g. one with no known frame) with the given diameter and border

     - parameter diameter:    The view's diameter
     - parameter borderColor: The border color
     - parameter borderWidth: The border width
     */
    func fullyRound(diameter: CGFloat, borderColor: UIColor, borderWidth: CGFloat) {
        layer.masksToBounds = true
        layer.cornerRadius = diameter / 2
        layer.borderWidth = borderWidth
        layer.borderColor = borderColor.cgColor;
    }

}

private extension UIView {

    @discardableResult func _round(corners: UIRectCorner, radius: CGFloat) -> CAShapeLayer {
        let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        self.layer.mask = mask
        return mask
    }

    func addBorder(mask: CAShapeLayer, borderColor: UIColor, borderWidth: CGFloat) {
        let borderLayer = CAShapeLayer()
        borderLayer.path = mask.path
        borderLayer.fillColor = UIColor.clear.cgColor
        borderLayer.strokeColor = borderColor.cgColor
        borderLayer.lineWidth = borderWidth
        borderLayer.frame = bounds
        layer.addSublayer(borderLayer)
    }

}

回答3:

Swift 3 - Useful UIView extension when you need to round specific corners of some views:

extension UIView {
  func round(corners: UIRectCorner, radius: CGFloat) {
    let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
    let mask = CAShapeLayer()
    mask.path = path.cgPath
    self.layer.mask = mask
  }
}

then just use it like this:

someView.round(corners: [.topLeft, .topRight], radius: 5)

回答4:

Swift 4+, iOS 11+

If you already have a UIView named myView referenced as an IBOutlet, try adding the following two lines in ViewDidLoad() or wherever it's being loaded:

myView.layer.cornerRadius = 10
myView.layer.maskedCorners = [.layerMinXMaxYCorner, .layerMaxXMaxYCorner]

You can change the array [] to any combination of MinX, MinY, MaxX, and MaxY to select the desired corners. The above example rounds the bottom two corners.

This is just another approach, can be a bit simpler depending on your design.

回答5:

Building on top of Sanjay's excellent answer, I wrote a quick CALayer extension for Swift 2.3, in case you need to do this sort of "only round some corners" thing more than once.

extension CALayer {
  func roundCorners(corners: UIRectCorner, radius: CGFloat) {
    let maskPath = UIBezierPath(roundedRect: bounds,
                                byRoundingCorners: corners,
                                cornerRadii: CGSize(width: radius, height: radius))

    let shape = CAShapeLayer()
    shape.path = maskPath.CGPath
    mask = shape
  }
}

Usage:

myView.layer.roundCorners([.TopLeft, .TopRight], radius: myCornerRadius)

Swift 3.0 (In this example the bounds came from the view not from the layer. Using the bounds from the view make this code to work with views in a UITableViewCell.):

func roundCorners(corners: UIRectCorner, radius: CGFloat, viewBounds: CGRect) {

    let maskPath = UIBezierPath(roundedRect: viewBounds,
                                byRoundingCorners: corners,
                                cornerRadii: CGSize(width: radius, height: radius))

    let shape = CAShapeLayer()
    shape.path = maskPath.cgPath
    mask = shape
}

Usage:

myView.layer.roundCorners(corners: [.topLeft, .topRight], radius: myCornerRadius, viewBounds: bounds)

回答6:

Here is what you do in Swift 2.0

var maskPath = UIBezierPath(roundedRect: anyView.bounds,
        byRoundingCorners: [.BottomLeft, .BottomRight],
        cornerRadii: CGSize(width: 10.0, height: 10.0))

回答7:

2017...

@IBDesignable
class RoundedEnds: UIView {

    override func layoutSubviews() { setup() } // "layoutSubviews" is best

    func setup() {
        let r = self.bounds.size.height / 2
        let path = UIBezierPath(roundedRect: self.bounds, cornerRadius:r)
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        self.layer.mask = mask
    }
}

For only some corners, just change to:

roundedRect: self.bounds,
  byRoundingCorners: [.topLeft, .topRight],
  cornerRadii: CGSize(width: r, height: r)

Note that as usual there have been many small changes in Swift, eg capitalization of constants, etc.

回答8:

Updated iWasRobbed's answer to work with the Swift 3.0 GM version:

import UIKit

extension UIView {

    /**
     Rounds the given set of corners to the specified radius

     - parameter corners: Corners to round
     - parameter radius:  Radius to round to
     */
    func round(corners: UIRectCorner, radius: CGFloat) {
        _round(corners: corners, radius: radius)
    }

    /**
     Rounds the given set of corners to the specified radius with a border

     - parameter corners:     Corners to round
     - parameter radius:      Radius to round to
     - parameter borderColor: The border color
     - parameter borderWidth: The border width
     */
    func round(corners: UIRectCorner, radius: CGFloat, borderColor: UIColor, borderWidth: CGFloat) {
        let mask = _round(corners: corners, radius: radius)
        addBorder(mask: mask, borderColor: borderColor, borderWidth: borderWidth)
    }

    /**
     Fully rounds an autolayout view (e.g. one with no known frame) with the given diameter and border

     - parameter diameter:    The view's diameter
     - parameter borderColor: The border color
     - parameter borderWidth: The border width
     */
    func fullyRound(diameter: CGFloat, borderColor: UIColor, borderWidth: CGFloat) {
        layer.masksToBounds = true
        layer.cornerRadius = diameter / 2
        layer.borderWidth = borderWidth
        layer.borderColor = borderColor.cgColor;
    }

}

private extension UIView {

    @discardableResult func _round(corners: UIRectCorner, radius: CGFloat) -> CAShapeLayer {
        let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        self.layer.mask = mask
        return mask
    }

    func addBorder(mask: CAShapeLayer, borderColor: UIColor, borderWidth: CGFloat) {
        let borderLayer = CAShapeLayer()
        borderLayer.path = mask.path
        borderLayer.fillColor = UIColor.clear.cgColor
        borderLayer.strokeColor = borderColor.cgColor
        borderLayer.lineWidth = borderWidth
        borderLayer.frame = bounds
        layer.addSublayer(borderLayer)
    }

}

回答9:

Objective-C version of iWasRobbed's answer:

UIView+RoundCorners.h

#import <UIKit/UIKit.h>

@interface UIView (RoundCorners)

/**
 Rounds the given set of corners to the specified radius

 - parameter corners: Corners to round
 - parameter radius:  Radius to round to
 */
- (void)roundCorners:(UIRectCorner)corners radius:(CGFloat)radius;

/**
 Rounds the given set of corners to the specified radius with a border

 - parameter corners:     Corners to round
 - parameter radius:      Radius to round to
 - parameter borderColor: The border color
 - parameter borderWidth: The border width
 */
- (void)roundCorners:(UIRectCorner)corners radius:(CGFloat)radius borderColor:(UIColor *)borderColor borderWidth:(CGFloat)borderWidth;

/**
 Fully rounds an autolayout view (e.g. one with no known frame) with the given diameter and border

 - parameter diameter:    The view's diameter
 - parameter borderColor: The border color
 - parameter borderWidth: The border width
 */
- (void)fullyRoundWithDiameter:(CGFloat)diameter borderColor:(UIColor *)borderColor borderWidth:(CGFloat)borderWidth;

@end

UIView+RoundCorners.m

#import "UIView+RoundCorners.h"

@implementation UIView (RoundCorners)

- (void)roundCorners:(UIRectCorner)corners radius:(CGFloat)radius {
    [self _roundCorners:corners radius:radius];
}

- (void)roundCorners:(UIRectCorner)corners radius:(CGFloat)radius borderColor:(UIColor *)borderColor borderWidth:(CGFloat)borderWidth {
    CAShapeLayer *mask = [self _roundCorners:corners radius:radius];
    [self addBorderWithMask:mask borderColor:borderColor borderWidth:borderWidth];
}

- (void)fullyRoundWithDiameter:(CGFloat)diameter borderColor:(UIColor *)borderColor borderWidth:(CGFloat)borderWidth {
    self.layer.masksToBounds = YES;
    self.layer.cornerRadius = diameter / 2;
    self.layer.borderWidth = borderWidth;
    self.layer.borderColor = borderColor.CGColor;
}

- (CAShapeLayer *)_roundCorners:(UIRectCorner)corners radius:(CGFloat)radius {
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:corners cornerRadii:CGSizeMake(radius, radius)];
    CAShapeLayer *mask = [CAShapeLayer layer];
    mask.path = path.CGPath;
    self.layer.mask = mask;
    return mask;
}

- (void)addBorderWithMask:(CAShapeLayer *)mask borderColor:(UIColor *)borderColor borderWidth:(CGFloat)borderWidth {
    CAShapeLayer *borderLayer = [CAShapeLayer layer];
    borderLayer.path = mask.path;
    borderLayer.fillColor = UIColor.clearColor.CGColor;
    borderLayer.strokeColor = borderColor.CGColor;
    borderLayer.lineWidth = borderWidth;
    borderLayer.frame = self.bounds;
    [self.layer addSublayer:borderLayer];
}

@end

回答10:

Swift 4:

let maskPath = UIBezierPath(
            roundedRect: view.bounds,
            byRoundingCorners: [.allCorners],
            cornerRadii: CGSize(width: 10.0, height: 10.0)
        )

let shape = CAShapeLayer()
shape.path = maskPath.cgPath

view.layer.mask = shape