属性简介:

// 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