ios--Attributes和ParagraphStyle介绍

NSMutableParagraphStyle的部分属性：

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];