正则表达试
if ([html isKindOfClass:[NSStringclass]])
{
html = [html stringByReplacingOccurrencesOfRegex:@"@\\b(\\w+)\\b"
withString:@"<a href=\"at:$1\" style=\"color:#3485CE\">@$1</a>"];
// #话题#还有bug:文字中间不能有空格
html = [html stringByReplacingOccurrencesOfRegex:@"#\\b(\\w*)#"
withString:@"<a href=\"topic:$1\" style=\"color:#3485CE\">#$1#</a>"];
// 链接
NSString *urlRegex = @"(https?)://([a-zA-Z0-9\\-.]+)((?:/[a-zA-Z0-9\\-._?,:'+\\&%$=~*!():@\\\\]*)+)?";
html = [html stringByReplacingOccurrencesOfRegex:urlRegex
withString:@"<a href=\"$1://$2$3\" style=\"color:#3485CE\">$1://$2$3</a>"];
}