MacOS 开发

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简介

NSParagraphStyleAttributeName 用于设置 NSAttributedString，和 NSFontAttributeName 类似。
不同的是：NSParagraphStyleAttributeName 是设置段落风格，NSFontAttributeName是设置字体。

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使用方法

- (void)drawRect:(NSRect)dirtyRect {    [super drawRect:dirtyRect];    NSMutableParagraphStyle *textStyle = [[NSMutableParagraphStyle alloc] init];    [textStyle setAlignment:NSTextAlignmentCenter];    [textStyle setLineBreakMode:NSLineBreakByTruncatingTail];    NSDictionary *attributes = @{NSFontAttributeName: [NSFont systemFontOfSize:18],                                 NSForegroundColorAttributeName: [NSColor whiteColor],                                 NSParagraphStyleAttributeName: textStyle};    float w = self.frame.size.width;    float h = self.frame.size.height;    float str_h = 20;    NSAttributedString *attributedText4 = [[NSAttributedString alloc] initWithString:@"这是一个 string" attributes:attributes];}

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计算段落高度

 - (void)countHeight{    NSString *originStr = @"ashdhsaksah 和就会撒大声地哈萨克的";    NSMutableAttributedString *attriStr = [[NSMutableAttributedString alloc] initWithString:originStr];    NSFont *descFont = [NSFont systemFontOfSize:16];    NSMutableParagraphStyle *descStyle = [[NSMutableParagraphStyle alloc]init];    [descStyle setLineSpacing:1];//行间距    CGFloat destinW = 100;    CGSize descSize = [originStr boundingRectWithSize:CGSizeMake(destinW, MAXFLOAT)                                                options:NSStringDrawingUsesLineFragmentOrigin                                             attributes:@{NSFontAttributeName:descFont,                                                          NSParagraphStyleAttributeName :descStyle}                                                context:nil].size;}

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相关属性

NSMutableParagraphStyle与NSParagraphStyle包括一下属性

alignment - 对齐方式

firstLineHeadIndent - 首行缩进

headIndent - 缩进

tailIndent - 尾部缩进

lineBreakMode - 断行方式

maximumLineHeight - 最大行高

minimumLineHeight - 最低行高

lineSpacing - 行距

paragraphSpacing -段距

paragraphSpacingBefore - 段首空间

baseWritingDirection - 句子方向

lineHeightMultiple - 可变行高,乘因数。

hyphenationFactor - 连字符属性

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参考：http://www.jianshu.com/p/4bb42470cfdd

- (void)setParagraphStyle{    NSMutableParagraphStyle *paragraphStyle = [NSMutableParagraphStyle new];    paragraphStyle.lineSpacing = 20.;// 行间距    paragraphStyle.lineHeightMultiple = 1.5;// 行高倍数（1.5倍行高）    paragraphStyle.firstLineHeadIndent = 30.0f;//首行缩进    paragraphStyle.minimumLineHeight = 10;//最低行高    paragraphStyle.maximumLineHeight = 20;//最大行高(会影响字体)    paragraphStyle.alignment = NSTextAlignmentLeft;// 对齐方式    paragraphStyle.defaultTabInterval = 144;// 默认Tab 宽度    paragraphStyle.headIndent = 20;// 起始 x位置    paragraphStyle.tailIndent = 320;// 结束 x位置（不是右边间距，与inset 不一样）    paragraphStyle.paragraphSpacing = 44.;// 段落间距    paragraphStyle.paragraphSpacingBefore = 44.;// 段落头部空白(实测与上边的没差啊？)    paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;// 分割模式    paragraphStyle.baseWritingDirection = NSWritingDirectionRightToLeft;// 段落方向}

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lineBreakMode 分割模式

NSLineBreakByWordWrapping = 0,  // Wrap at word boundaries, defaultNSLineBreakByCharWrapping,  // Wrap at character boundariesNSLineBreakByClipping,  // Simply clipNSLineBreakByTruncatingHead, // Truncate at head of line: "...wxyz"NSLineBreakByTruncatingTail, // Truncate at tail of line: "abcd..."NSLineBreakByTruncatingMiddle // Truncate middle of line:  "ab...yz"

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段落方向 baseWritingDirection

     NSWritingDirectionNatural       = -1,    // Determines direction using the Unicode Bidi Algorithm rules P2 and P3     NSWritingDirectionLeftToRight   =  0,    // Left to right writing direction     NSWritingDirectionRightToLeft   =  1