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:
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];