求2个正则表达式，分数不够可以再加

Question

取出一个页面中关于keywords和description的meta主要有以下几种情况
<meta name="keywords" content="123" />
<meta name="description" content="321" /><meta  content="123" name="keywords" />
<meta  content="321" name="description"  /><meta id="fdsafds" name="keywords" content="123" />
<meta id="fdsafdsa"  name="description" content="321" />以上几种情况都存在
1、没有双引号，也没有单引号
2、只有单引号
3、存在空格的地方都有可能是多个空格
4、大小写问题
5、可能会存在干扰的问题，如同时存在
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="Content-Language" content="zh-CN" /> 
<meta name="author" content="Csdn" /> 

Answer 1

回2楼，比如<meta name=keywords content=123 />
<meta name=description content=321 /><meta name='keywords' content='123' />
<meta name='description' content='321' />
<meta         name='keywords'        content='123' />
<meta         name='description'     content='321' />

Answer 2

            string str = @"<meta name=""keywords"" content=""123"" />
<meta name=description content=""321"" />
<meta content=""123"" name=keywords />
<meta content=""321"" name=""description"" />
<meta id=""fdsafds"" name=""keywords"" content=""123"" />
<meta id=""fdsafdsa"" name=description content=""321"" />";
            Regex reg = new Regex(@"<meta[^>]+name=[""|']?(keywords|description)[""|']?[^>]+>");
            MatchCollection mc = reg.Matches(str);            foreach (Match m in mc)
            {
                Console.WriteLine(m.Groups[0].ToString());
            }            /*
            <meta name="keywords" content="123" />
            <meta name=description content="321" />
            <meta content="123" name=keywords />
            <meta content="321" name="description" />
            <meta id="fdsafds" name="keywords" content="123" />
            <meta id="fdsafdsa" name=description content="321" />
            */

Answer 3

try...Regex reg = new Regex(@"(?i)<meta[^>]*?name=(['""]?)(keywords|description)\1[^>]*>");
MatchCollection mc = reg.Matches(yourStr);
foreach (Match m in mc)
{
    richTextBox2.Text += m.Value + "\n";
}

Answer 4

我错了，我有罪，我没说清楚，我想取得是keywords和description的值，如
<meta name="keywords" content="123" />我想得到 123，可以用两个正则表达式，分别去keywords和description

Answer 5

        private static void TestRegex11()
        {
            string html = @"<meta name=""keywords"" content=""123"" />
<meta name=""description"" content=""321"" /><meta content=""123"" name=""keywords"" />
<meta content=""321"" name=""description"" /><meta id=""fdsafds"" name=""keywords"" content=""123"" />
<meta id=""fdsafdsa"" name=""description"" content=""321"" />";
            MatchCollection keywords = Regex.Matches(html, @"(?<=<meta(?=[^>]+?name=""keywords"").+?content="")[^""]+");
            MatchCollection descriptions = Regex.Matches(html, @"(?<=<meta(?=[^>]+?name=""description"").+?content="")[^""]+");
            Console.WriteLine("keywords");
            foreach (Match key in keywords)
            {
                Console.WriteLine(key.Value);
            }
            Console.WriteLine("descriptions");
            foreach (Match description in descriptions)
            {
                Console.WriteLine(description.Value);
            }
        }
没给你配对顺序。你可以自己吧keyword和description配对起来。顺序应该是一样的。

Answer 6

如果加上最初的，'"的限制，可以优化为：        private static void TestRegex11()
        {
            string html = @"<meta name=""keywords"" content=""123"" />
<meta name=""description"" content=""321"" /><meta content=""123"" name=""keywords"" />
<meta content=""321"" name=""description"" /><meta id=""fdsafds"" name=""keywords"" content=""123"" />
<meta id=""fdsafdsa"" name=""description"" content=""321"" />";
            MatchCollection keywords = Regex.Matches(html, @"(?<=<meta(?=[^>]+?name=(['""]?)keywords\1).+?content=(['""])?)[^""]+(?=\1| )");
            MatchCollection descriptions = Regex.Matches(html, @"(?<=<meta(?=[^>]+?name=(['""]?)description\1).+?content=(['""])?)[^""]+(?=\1| )");
            Console.WriteLine("keywords");
            foreach (Match key in keywords)
            {
                Console.WriteLine(key.Value);
            }
            Console.WriteLine("descriptions");
            foreach (Match description in descriptions)
            {
                Console.WriteLine(description.Value);
            }
        }

Answer 7

@"(?is)(?<=<meta(?=((?!name).)*name=['""]?(keywords|description)[""'\s>]?)((?!content).)*content=[""']?)[^'""\s>]+"

Answer 8

正常情况下都可以，但当我把字符串改成这样就不行了          string html = @"<meta  name=""keywords""   content=""123""  />
<meta name=""description"" content=""321"" /><meta content='123hhhhhh'     name='keywords'   />
<meta content=""321ggggggg"" name=""description"" /><meta id=fdsafds name=keywords content=123 />
<meta id=""fdsafdsa"" name=""description"" content=""321"" />";

Answer 9

修改一下        private static void TestRegex12()
        {
            string html = @"<meta  name=""keywords""   content=""123""  />
<meta name=""description"" content=""321"" /><meta content='123hhhhhh'     name='keywords'   />
<meta content=""321ggggggg"" name=""description"" /><meta id=fdsafds name=keywords content=123 />
<meta id=""fdsafdsa"" name=""description"" content=""321"" />";
            MatchCollection keywords = Regex.Matches(html, @"(?<=<meta(?=[^>]+?name=(['""]?)keywords\1).+?content=(['""]?))[^'"">\s]+(?=\1| )");
            MatchCollection descriptions = Regex.Matches(html, @"(?<=<meta(?=[^>]+?name=(['""]?)keywords\1).+?content=(['""]?))[^'"">\s]+(?=\1| )");
            Console.WriteLine("keywords");
            foreach (Match key in keywords)
            {
                Console.WriteLine(key.Value);
            }
            Console.WriteLine("descriptions");
            foreach (Match description in descriptions)
            {
                Console.WriteLine(description.Value);
            }
        }