NSMutableAttributedString及NSMutableParagraphStyle的使用

时间:2023-02-01 00:16:49

一、在iOS开发中,常常会有一段文字显示不同的颜色和字体,或者给某几个文字加删除线或下划线的需求。之前在网上找了一些资料,有的是重绘UILabel的textLayer,有的是用html5实现的,都比较麻烦,而且很多UILabel的属性也不起作用了,效果都不理想。后来了解到NSMuttableAttstring(带属性的字符串),上面的一些需求都可以很简便的实现。

1.实例化方法和使用方法

实例化方法:

使用字符串初始化

- (id)initWithString:(NSString *)str;

- (id)initWithString:(NSString *)str attributes:(NSDictionary *)attrs;

 

字典中存放一些属性名和属性值,如:

NSDictionary *attributeDict = [NSDictionarydictionaryWithObjectsAndKeys:

                                    [UIFontsystemFontOfSize:15.0],NSFontAttributeName,

                                    [UIColorredColor],NSForegroundColorAttributeName,

                                   NSUnderlineStyleAttributeName,NSUnderlineStyleSingle,nil];

NSMutableAttributedString *AttributedStr = [[NSMutableAttributedStringalloc]initWithString:@"今天天气不错呀" attributes:attributeDict];

- (id)initWithAttributedString:(NSAttributedString *)attester;

使用NSAttributedString初始化,跟NSMutableString,NSString类似

 

使用方法:

为某一范围内文字设置多个属性

- (void)setAttributes:(NSDictionary *)attrs range:(NSRange)range;

为某一范围内文字添加某个属性

- (void)addAttribute:(NSString *)name value:(id)value range:(NSRange)range;

为某一范围内文字添加多个属性

- (void)addAttributes:(NSDictionary *)attrs range:(NSRange)range;

移除某范围内的某个属性

- (void)removeAttribute:(NSString *)name range:(NSRange)range;

 

*常见的属性及说明

NSFontAttributeName  字体

NSParagraphStyleAttributeName  段落格式 

NSForegroundColorAttributeName  字体颜色

NSBackgroundColorAttributeName   背景颜色

NSStrikethroughStyleAttributeName 删除线格式

NSUnderlineStyleAttributeName      下划线格式

NSStrokeColorAttributeName        删除线颜色

NSStrokeWidthAttributeName 删除线宽度

NSShadowAttributeName  阴影

更多方法和属性说明详见苹果官方说明文档:

https://developer.apple.com/library/ios/documentation/Cocoa/Reference/Foundation/Classes/NSMutableAttributedString_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40003689

 

使用实例:

//描述设置行距

    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];

    [paragraphStyle setLineSpacing:4.0f];

 //设置字体

 NSDictionary *deitalAttributes = @{NSFontAttributeName :lbl_fetusDesc.font,

                                       NSParagraphStyleAttributeName: paragraphStyle};

NSString *descStr = (self.topViewType == PregnantTopViewTypePregnant) ? _pregInfo.personateFetusAdviceDesc  : _pregInfo.bbchange;

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:descStr];

[attributedString addAttributes:deitalAttributes range:NSMakeRange(0, [descStr length])];

二、在上面用到了NSMutableParagraphStyle设置行间距,下面列举一下NSMutableParagraphStyle的用处

//   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];