创建拉伸不变形的图片

/**
*  返回一张可以随意拉伸不变形的图片
*
*  @param name 图片名字
*/
+ (UIImage *)resizableImage:(NSString *)name
{
    UIImage *normal = [UIImage imageNamed:name];
    CGFloat w = normal.size.width * 0.5;
    CGFloat h = normal.size.height * 0.5;
    return [normal resizableImageWithCapInsets:UIEdgeInsetsMake(h, w, h, w)];
}


还有两种方法可以完成改功能
// 拉伸图片
//        [normal stretchableImageWithLeftCapWidth:(NSInteger) topCapHeight:(NSInteger)];
//        [normal resizableImageWithCapInsets:(UIEdgeInsets) resizingMode:(UIImageResizingMode)];