#import <UIKit/UIKit.h>

@interface UIImage (Extension)
/**
 * 传入图片的名称,返回一张可拉伸不变形的图片
 *
 * @param imageName 图片名称
 *
 * @return 可拉伸图片
 */
+ (UIImage *)resizableImageWithName:(NSString *)imageName;
@end

#import "UIImage+Extension.h"

@implementation UIImage (Extension)

+ (UIImage *)resizableImageWithName:(NSString *)imageName
{

  // 加载原有图片
  UIImage *norImage = [UIImage imageNamed:imageName];
  // 获取原有图片的宽高的一半
  CGFloat w = norImage.size.width * 0.5;
  CGFloat h = norImage.size.height * 0.5;
  // 生成可以拉伸指定位置的图片
  UIImage *newImage = [norImage resizableImageWithCapInsets:UIEdgeInsetsMake(h, w, h, w) resizingMode:UIImageResizingModeStretch];

  return newImage;
}
@end