这是Uri。IsWellFormedUriString和Uri。TryCreate方法,但它们似乎为文件路径返回true,等等。

我如何检查字符串是否是一个有效的(不一定是活动的)HTTP URL用于输入验证目的?


当前回答

试着验证HTTP url (uriName是你想测试的URI):

Uri uriResult;
bool result = Uri.TryCreate(uriName, UriKind.Absolute, out uriResult) 
    && uriResult.Scheme == Uri.UriSchemeHttp;

或者,如果你想同时接受有效的HTTP和HTTPS url(根据J0e3gan的评论):

Uri uriResult;
bool result = Uri.TryCreate(uriName, UriKind.Absolute, out uriResult) 
    && (uriResult.Scheme == Uri.UriSchemeHttp || uriResult.Scheme == Uri.UriSchemeHttps);

其他回答

这里的所有答案要么允许使用其他方案的url(例如,file://, ftp://)),要么拒绝以http://或https://开头的人类可读的url(例如,www.google.com),这在处理用户输入时并不好。

我是这样做的:

public static bool ValidHttpURL(string s, out Uri resultURI)
{
    if (!Regex.IsMatch(s, @"^https?:\/\/", RegexOptions.IgnoreCase))
        s = "http://" + s;

    if (Uri.TryCreate(s, UriKind.Absolute, out resultURI))
        return (resultURI.Scheme == Uri.UriSchemeHttp || 
                resultURI.Scheme == Uri.UriSchemeHttps);

    return false;
}

用法:

string[] inputs = new[] {
                          "https://www.google.com",
                          "http://www.google.com",
                          "www.google.com",
                          "google.com",
                          "javascript:alert('Hack me!')"
                        };
foreach (string s in inputs)
{
    Uri uriResult;
    bool result = ValidHttpURL(s, out uriResult);
    Console.WriteLine(result + "\t" + uriResult?.AbsoluteUri);
}

输出:

True    https://www.google.com/
True    http://www.google.com/
True    http://www.google.com/
True    http://google.com/
False
    public static bool CheckURLValid(this string source)
    {
        Uri uriResult;
        return Uri.TryCreate(source, UriKind.Absolute, out uriResult) && uriResult.Scheme == Uri.UriSchemeHttp;
    }

用法:

string url = "htts://adasd.xc.";
if(url.CheckUrlValid())
{
  //valid process
}

更新:(单行代码)谢谢@GoClimbColorado

public static bool CheckURLValid(this string source) => Uri.TryCreate(source, UriKind.Absolute, out Uri uriResult) && uriResult.Scheme == Uri.UriSchemeHttps;

用法:

string url = "htts://adasd.xc.";
if(url.CheckUrlValid())
{
  //valid process
}

试一试:

bool IsValidURL(string URL)
{
    string Pattern = @"^(?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~:/?#[\]@!\$&'\(\)\*\+,;=.]+$";
    Regex Rgx = new Regex(Pattern, RegexOptions.Compiled | RegexOptions.IgnoreCase);
    return Rgx.IsMatch(URL);
}

它会接受这样的URL:

http (s): / / www . example . com http (s): / / stackoverflow操作。com http (s): / / www . example . com/page http (s): / / www . example . com/page ? id = 1&product = 2 http (s): / / www . example . com/page #开始 http (s) / www . example . com: 8080 http (s): / / 127 . 0 0。1 127 . 0 0。1 www.example.com 操作。com

我创建了这个函数来帮助我进行URL验证,你可以根据自己的喜好定制它,注意这是用python3.10.6编写的

def url_validator(url: str) -> bool:
    """
    use this func to filter out the urls to follow only valid urls
    :param: url
    :type: str
    :return: True if the passed url is valid otherwise return false
    :rtype: bool
    """

    #the following regex is copied from Django source code 
    # to validate a url using regax
    
    regex = re.compile(
        r"^(?:http|ftp)s?://"  # http:// or https://
        r"(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|"  # domain...
        r"localhost|"  # localhost...
        r"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})"  # ...or ip
        r"(?::\d+)?"  # optional port
        r"(?:/?|[/?]\S+)$",
        re.IGNORECASE,
    )


    blocked_sites: list[str] = []

    for site in blocked_sites:
        if site in url or site == url:
            return False

    # if none of the above then ensure that the url is valid and then return True otherwise return False
    if re.match(regex, url):
        return True

    return False

此方法在http和https中都可以正常工作。只有一行:)

if (Uri.IsWellFormedUriString("https://www.google.com", UriKind.Absolute))

MSDN: IsWellFormedUriString