Label订制NSMutableParagraphStyle ／NSParagraphStyle

typedef NS_ENUM(NSInteger, NSLineBreakMode) {/* What to do with long lines */
NSLineBreakByWordWrapping = 0,	 /* Wrap at word boundaries, default */
NSLineBreakByCharWrapping,/* Wrap at character boundaries */
NSLineBreakByClipping,/* Simply clip */剪掉后面显示不了的部分
NSLineBreakByTruncatingHead,/* Truncate at head of line: "...wxyz" */头部分的内容以……方式省略
NSLineBreakByTruncatingTail,/* Truncate at tail of line: "abcd..." */结尾部分的内容以……方式省略
NSLineBreakByTruncatingMiddle/* Truncate middle of line:  "ab...yz" */中间部分的内容以……方式省略
} NS_ENUM_AVAILABLE_IOS(6_0);

typedef NS_ENUM(NSInteger, NSWritingDirection) {
NSWritingDirectionNatural	   = -1,	// Determines direction using the Unicode Bidi Algorithm rules P2 and P3
NSWritingDirectionLeftToRight   =  0,	// Left to right writing direction 左到右的书写方向
NSWritingDirectionRightToLeft   =  1	// Right to left writing direction 右到左的书写方向
} NS_ENUM_AVAILABLE_IOS(6_0);

//   NSParagraphStyleAttributeName 段落的风格（设置首行，行间距，对齐方式什么的）看自己需要什么属性，写什么
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 10;// 字体的行间距
paragraphStyle.firstLineHeadIndent = 20.0f;//首行缩进
paragraphStyle.alignment = NSTextAlignmentJustified;//（两端对齐的）文本对齐方式：（左，中，右，两端对齐，自然）
paragraphStyle.lineBreakMode = NSLineBreakByTruncatingTail;//结尾部分的内容以……方式省略 ( "...wxyz" ,"abcd..." ,"ab...yz")
paragraphStyle.headIndent = 20;//整体缩进(首行除外)
paragraphStyle.tailIndent = 20;//
paragraphStyle.minimumLineHeight = 10;//最低行高
paragraphStyle.maximumLineHeight = 20;//最大行高
paragraphStyle.paragraphSpacing = 15;//段与段之间的间距
paragraphStyle.paragraphSpacingBefore = 22.0f;//段首行空白空间/* Distance between the bottom of the previous paragraph (or the end of its paragraphSpacing, if any) and the top of this paragraph. */
paragraphStyle.baseWritingDirection = NSWritingDirectionLeftToRight;//从左到右的书写方向（一共➡️三种）
paragraphStyle.lineHeightMultiple = 15;/* Natural line height is multiplied by this factor (if positive) before being constrained by minimum and maximum line height. */
paragraphStyle.hyphenationFactor = 1;//连字属性 在iOS，唯一支持的值分别为0和1

/*
NSFontAttributeName 字体大小
NSParagraphStyleAttributeName 段落的风格（设置首行，行间距，对齐方式什么的）
NSKernAttributeName 字间距
*/
NSDictionary *attributes = @{
NSFontAttributeName:[UIFont systemFontOfSize:15],
NSParagraphStyleAttributeName:paragraphStyle,
NSKernAttributeName:@(10),

};
textView.attributedText = [[NSAttributedString alloc] initWithString:textView.text attributes:attributes];