/* Predefined character attributes for text. If the key is not in the dictionary, then use the default values as described below. // 预约义的文本属性值,若是键不是一个字典,那么使用默认的值做为如下描述
UIKIT_EXTERN NSString *const NSKernAttributeName NS_AVAILABLE_IOS(6_0); // NSNumber containing floating point value, in points; amount to modify default kerning. 0 means kerning is disabled. (note: values other than nil and 0 are unsupported on iOS)
UIKIT_EXTERN NSString *const NSStrokeColorAttributeName NS_AVAILABLE_IOS(6_0); // UIColor, default nil: same as foreground color
UIKIT_EXTERN NSString *const NSStrokeWidthAttributeName NS_AVAILABLE_IOS(6_0); // NSNumber containing floating point value, in percent of font point size, default 0: no stroke; positive for stroke alone, negative for stroke and fill (a typical value for outlined text would be 3.0)
UIKIT_EXTERN NSString *const NSLinkAttributeName NS_AVAILABLE_IOS(7_0); // NSURL (preferred) or NSString
UIKIT_EXTERN NSString *const NSBaselineOffsetAttributeName NS_AVAILABLE_IOS(7_0); // NSNumber containing floating point value, in points; offset from baseline, default 0
UIKIT_EXTERN NSString *const NSUnderlineColorAttributeName NS_AVAILABLE_IOS(7_0); // UIColor, default nil: same as foreground color
UIKIT_EXTERN NSString *const NSStrikethroughColorAttributeName NS_AVAILABLE_IOS(7_0); // UIColor, default nil: same as foreground color
UIKIT_EXTERN NSString *const NSObliquenessAttributeName NS_AVAILABLE_IOS(7_0); // NSNumber containing floating point value; skew to be applied to glyphs, default 0: no skew
UIKIT_EXTERN NSString *const NSExpansionAttributeName NS_AVAILABLE_IOS(7_0); // NSNumber containing floating point value; log of expansion factor to be applied to glyphs, default 0: no expansion
UIKIT_EXTERN NSString *const NSWritingDirectionAttributeName NS_AVAILABLE_IOS(7_0); // NSArray of NSNumbers representing the nested levels of writing direction overrides as defined by Unicode LRE, RLE, LRO, and RLO characters. The control characters can be obtained by masking NSWritingDirection and NSTextWritingDirection values. LRE: NSWritingDirectionLeftToRight|NSTextWritingDirectionEmbedding, RLE: NSWritingDirectionRightToLeft|NSTextWritingDirectionEmbedding, LRO: NSWritingDirectionLeftToRight|NSTextWritingDirectionOverride, RLO: NSWritingDirectionRightToLeft|NSTextWritingDirectionOverride,
UIKIT_EXTERN NSString *const NSVerticalGlyphFormAttributeName NS_AVAILABLE_IOS(6_0); // An NSNumber containing an integer value. 0 means horizontal text. 1 indicates vertical text. If not specified, it could follow higher-level vertical orientation settings. Currently on iOS, it's always horizontal. The behavior for any other value is undefined.
*/
// NSParagraphStyle 段落样式
// typedef NS_ENUM(NSInteger, NSLineBreakMode) { /* What to do with long lines */ //对于长内容或多行内容的处理方式
// NSLineBreakByWordWrapping = 0, /* Wrap at word boundaries, default */ //按包含单词为界限截断
// NSLineBreakByCharWrapping, /* Wrap at character boundaries */ //按字符为界限截断