如何检查字符串是否是有效的HTTP URL？

Question

有Uri.IsWellFormedUriString和Uri.TryCreate方法,但它们似乎返回true文件路径等.

如何检查字符串是否是用于输入验证的有效(不一定是活动的)HTTP URL？

Answer 1

尝试此操作来验证HTTP URL(uriName是您要测试的URI):

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

或者,如果您要同时接受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);

Answer 2

此方法在http和https中均可正常工作.只需一行:)

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

MSDN:IsWellFormedUriString

Answer 3

    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)感谢@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
}

Answer 4

试试看：

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

它将接受这样的 URL：

• http(s)://www.example.com
• http(s)://stackoverflow.example.com
• http(s)://www.example.com/page
• http(s)://www.example.com/page?id=1&product=2
• http(s)://www.example.com/page#start
• http(s)://www.example.com:8080
• http(s)://127.0.0.1
• 127.0.0.1
• www.example.com
• 例子.com

Answer 5

这里所有的答案,或者允许与其他方案的网址(例如file://,ftp://)或拒绝人类可读的网址不启动http://或https://(例如www.google.com)与用户输入打交道时,这是不好的.

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

Answer 6

之后Uri.TryCreate你可以查看Uri.Scheme它是否是HTTP(s).

Answer 7

作为使用正则表达式的另一种方法，此代码使用Uri.TryCreate每个 OP，但随后还会检查结果以确保其方案是 http 或 https 之一：

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