NSMutableAttributedString(富文本)的简单使用

#import "ViewController.h"
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(20, 84, self.view.frame.size.width-40, self.view.frame.size.height-84-20)];
    label.text = @"春种一粒粟，秋成万颗子。\n四海无闲田，农夫犹饿死。\n锄禾日当午，汗滴禾下土。\n谁知盘中餐，粒粒皆辛苦。";
    [self.view addSubview:label];
    NSRange rangeOne = [label.text rangeOfString:@"春种一粒粟"];
    NSRange rangeTwo = [label.text rangeOfString:@"秋成万颗子"];
    NSRange rangeThree = [label.text rangeOfString:@"四海无闲田"];
    NSRange rangeFour = [label.text rangeOfString:@"农夫犹饿死"];
    NSRange rangeFive = [label.text rangeOfString:@"锄禾日当午"];
    NSRange rangeSix = [label.text rangeOfString:@"汗滴禾下土"];
    NSRange rangeSeven = [label.text rangeOfString:@"谁知盘中餐"];
    NSRange rangeEight = [label.text rangeOfString:@"粒粒皆辛苦"];
    NSMutableAttributedString *attributedLabel = [[NSMutableAttributedString alloc] initWithString:label.text];
    //字体
    [attributedLabel addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:18] range:NSMakeRange(0, label.text.length)];
    //段落
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.lineSpacing = 20; //行间距
    paragraphStyle.alignment = NSTextAlignmentCenter;
    [attributedLabel addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, label.text.length)];
    //字体颜色
    [attributedLabel addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(rangeOne.location, rangeOne.length)];
    //字体底色
    [attributedLabel addAttribute:NSBackgroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(rangeTwo.location, rangeTwo.length)];
    //删除线
    [attributedLabel addAttribute:NSStrikethroughStyleAttributeName value:[NSNumber numberWithInt:3] range:NSMakeRange(rangeThree.location, rangeThree.length)];
    [attributedLabel addAttribute:NSStrikethroughColorAttributeName value:[UIColor redColor] range:NSMakeRange(rangeThree.location, rangeThree.length)];
    //下划线
    [attributedLabel addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:1] range:NSMakeRange(rangeFour.location, rangeFour.length)];
    [attributedLabel addAttribute:NSUnderlineColorAttributeName value:[UIColor redColor] range:NSMakeRange(rangeFour.location, rangeFour.length)];
    //文字间距
    [attributedLabel addAttribute:NSKernAttributeName value:[NSNumber numberWithInt:5] range:NSMakeRange(rangeFive.location, rangeFive.length)];
    //字体倾斜(正值右倾，负值左倾)
    [attributedLabel addAttribute:NSObliquenessAttributeName value:[NSNumber numberWithFloat:0.5] range:NSMakeRange(rangeSix.location, rangeSix.length)];
    //笔画宽度(正值中空，负值填充)
    [attributedLabel addAttribute:NSStrokeWidthAttributeName value:[NSNumber numberWithFloat:1] range:NSMakeRange(rangeSeven.location, rangeSeven.length)];
    //填充颜色
    [attributedLabel addAttribute:NSStrokeColorAttributeName value:[UIColor redColor] range:NSMakeRange(rangeSeven.location, rangeSeven.length)];
    //阴影效果
    NSShadow *shadow = [[NSShadow alloc] init];
    shadow.shadowColor = [UIColor redColor];
    shadow.shadowOffset = CGSizeMake(2, 2);
    shadow.shadowBlurRadius = 2;
    [attributedLabel addAttribute:NSShadowAttributeName value:shadow range:NSMakeRange(rangeEight.location, rangeEight.length)];
    //自适应高
    label.numberOfLines = 0;
    CGRect labelStringRect = [attributedLabel boundingRectWithSize:CGSizeMake(self.view.frame.size.width-label.frame.origin.x*2, 9999) options:NSStringDrawingUsesLineFragmentOrigin context:nil];
    CGRect labelRect = label.frame;
    labelRect.size.height = labelStringRect.size.height;
    label.frame = labelRect;
    
    label.attributedText = attributedLabel;
}

效果图如下：