过滤html里的标签获取纯文本

首先定义宏

#define REGEX_SCRIPT  @"<script[^>]*?>[\\s\\S]*?<\\/script>"
#define REGEX_STYLE   @"<style[^>]*?>[\\s\\S]*?<\\/style>"
#define REGEX_HTML    @"<[^>]+>"
#define REGEX_SPACE   @"\\s*|\t|\r|\n"
#define REGEX_DEL_P   @"</?[a|A][^>]*>"

之后就是一层层的过滤

- (NSString *)regexString:(NSString *)htmlString{
   
    NSRegularExpression *reExFirst = [NSRegularExpression regularExpressionWithPattern:REGEX_SCRIPT options:0 error:nil];
    htmlString = [reExFirst stringByReplacingMatchesInString:htmlString options:NSMatchingReportProgress range:NSMakeRange(0, htmlString.length) withTemplate:@""];
    
    NSRegularExpression *reExSecond = [NSRegularExpression regularExpressionWithPattern:REGEX_STYLE options:0 error:nil];
    htmlString = [reExSecond stringByReplacingMatchesInString:htmlString options:NSMatchingReportProgress range:NSMakeRange(0, htmlString.length) withTemplate:@""];
    
    NSRegularExpression *reExThird = [NSRegularExpression regularExpressionWithPattern:REGEX_HTML options:0 error:nil];
    htmlString = [reExThird stringByReplacingMatchesInString:htmlString options:NSMatchingReportProgress range:NSMakeRange(0, htmlString.length) withTemplate:@""];
    
    NSRegularExpression *reExFourth = [NSRegularExpression regularExpressionWithPattern:REGEX_SPACE options:0 error:nil];
    htmlString = [reExFourth stringByReplacingMatchesInString:htmlString options:NSMatchingReportProgress range:NSMakeRange(0, htmlString.length) withTemplate:@""];
    
    NSRegularExpression *reExFifth = [NSRegularExpression regularExpressionWithPattern:REGEX_DEL_P options:0 error:nil];
    htmlString = [reExFifth stringByReplacingMatchesInString:htmlString options:NSMatchingReportProgress range:NSMakeRange(0, htmlString.length) withTemplate:@""];
    
    
    return htmlString;
    
}