纯代码实现实现各种效果的圆角按钮。

#import <UIKit/UIKit.h>

@interface APRoundedButton : UIButton

@property (nonatomic, assign) int style;

@end

//
//  Created by Alberto Pasca on 27/02/14.
//  Copyright (c) 2014 albertopasca.it. All rights reserved.
//

#import "APRoundedButton.h"
#import <QuartzCore/QuartzCore.h>


@implementation APRoundedButton

- (void)awakeFromNib
{
  [super awakeFromNib];

  UIRectCorner corners;


  switch ( self.style )
  {
    case 0:
      corners = UIRectCornerBottomLeft;
      break;
    case 1:
      corners = UIRectCornerBottomRight;
      break;
    case 2:
      corners = UIRectCornerTopLeft;
      break;
    case 3:
      corners = UIRectCornerTopRight;
      break;
    case 4:
      corners = UIRectCornerBottomLeft | UIRectCornerBottomRight;
      break;
    case 5:
      corners = UIRectCornerTopLeft | UIRectCornerTopRight;
      break;
    case 6:
      corners = UIRectCornerBottomLeft | UIRectCornerTopLeft;
      break;
    case 7:
      corners = UIRectCornerBottomRight | UIRectCornerTopRight;
      break;
    case 8:
      corners = UIRectCornerBottomRight | UIRectCornerTopRight | UIRectCornerTopLeft;
      break;
    case 9:
      corners = UIRectCornerBottomRight | UIRectCornerTopRight | UIRectCornerBottomLeft;
      break;
    default:
      corners = UIRectCornerAllCorners;
      break;
  }


  UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds
                                                 byRoundingCorners:corners
                                                       cornerRadii:CGSizeMake(20.0, 30.0)];
  CAShapeLayer *maskLayer = [CAShapeLayer layer];
  maskLayer.frame         = self.bounds;
  maskLayer.path          = maskPath.CGPath;
  self.layer.mask         = maskLayer;
}


@end