Path.Combine很方便,但是.NET框架中是否有类似的URL函数?
我正在寻找这样的语法:
Url.Combine("http://MyUrl.com/", "/Images/Image.jpg")
这将返回:
"http://MyUrl.com/Images/Image.jpg"
Path.Combine很方便,但是.NET框架中是否有类似的URL函数?
我正在寻找这样的语法:
Url.Combine("http://MyUrl.com/", "/Images/Image.jpg")
这将返回:
"http://MyUrl.com/Images/Image.jpg"
当前回答
我必须指出,Path.Combine似乎也能直接实现这一点,至少在.NET 4上是如此。
其他回答
Path.Combine("Http://MyUrl.com/", "/Images/Image.jpg").Replace("\\", "/")
如果您不想拥有像Flurl这样的依赖项,可以使用它的源代码:
/// <summary>
/// Basically a Path.Combine for URLs. Ensures exactly one '/' separates each segment,
/// and exactly on '&' separates each query parameter.
/// URL-encodes illegal characters but not reserved characters.
/// </summary>
/// <param name="parts">URL parts to combine.</param>
public static string Combine(params string[] parts) {
if (parts == null)
throw new ArgumentNullException(nameof(parts));
string result = "";
bool inQuery = false, inFragment = false;
string CombineEnsureSingleSeparator(string a, string b, char separator) {
if (string.IsNullOrEmpty(a)) return b;
if (string.IsNullOrEmpty(b)) return a;
return a.TrimEnd(separator) + separator + b.TrimStart(separator);
}
foreach (var part in parts) {
if (string.IsNullOrEmpty(part))
continue;
if (result.EndsWith("?") || part.StartsWith("?"))
result = CombineEnsureSingleSeparator(result, part, '?');
else if (result.EndsWith("#") || part.StartsWith("#"))
result = CombineEnsureSingleSeparator(result, part, '#');
else if (inFragment)
result += part;
else if (inQuery)
result = CombineEnsureSingleSeparator(result, part, '&');
else
result = CombineEnsureSingleSeparator(result, part, '/');
if (part.Contains("#")) {
inQuery = false;
inFragment = true;
}
else if (!inFragment && part.Contains("?")) {
inQuery = true;
}
}
return EncodeIllegalCharacters(result);
}
/// <summary>
/// URL-encodes characters in a string that are neither reserved nor unreserved. Avoids encoding reserved characters such as '/' and '?'. Avoids encoding '%' if it begins a %-hex-hex sequence (i.e. avoids double-encoding).
/// </summary>
/// <param name="s">The string to encode.</param>
/// <param name="encodeSpaceAsPlus">If true, spaces will be encoded as + signs. Otherwise, they'll be encoded as %20.</param>
/// <returns>The encoded URL.</returns>
public static string EncodeIllegalCharacters(string s, bool encodeSpaceAsPlus = false) {
if (string.IsNullOrEmpty(s))
return s;
if (encodeSpaceAsPlus)
s = s.Replace(" ", "+");
// Uri.EscapeUriString mostly does what we want - encodes illegal characters only - but it has a quirk
// in that % isn't illegal if it's the start of a %-encoded sequence https://stackoverflow.com/a/47636037/62600
// no % characters, so avoid the regex overhead
if (!s.Contains("%"))
return Uri.EscapeUriString(s);
// pick out all %-hex-hex matches and avoid double-encoding
return Regex.Replace(s, "(.*?)((%[0-9A-Fa-f]{2})|$)", c => {
var a = c.Groups[1].Value; // group 1 is a sequence with no %-encoding - encode illegal characters
var b = c.Groups[2].Value; // group 2 is a valid 3-character %-encoded sequence - leave it alone!
return Uri.EscapeUriString(a) + b;
});
}
上面有托德·梅尼尔(Todd Menier)的评论,Flurl包括一个Url.Combine。
更多详情:
Url.Combine基本上是Url的Path.Combine,确保部分之间只有一个分隔符:
var url = Url.Combine(
"http://MyUrl.com/",
"/too/", "/many/", "/slashes/",
"too", "few?",
"x=1", "y=2"
// result: "http://www.MyUrl.com/too/many/slashes/too/few?x=1&y=2"
在NuGet上获取Flurl.Http:
PM>安装包Flurl.Http
或者获取没有HTTP功能的独立URL生成器:
PM>安装程序包Flurl
我们使用以下简单的助手方法将任意数量的URL部分连接在一起:
public static string JoinUrlParts(params string[] urlParts)
{
return string.Join("/", urlParts.Where(up => !string.IsNullOrEmpty(up)).ToList().Select(up => up.Trim('/')).ToArray());
}
注意,它不支持'..//something/page.htm'样式的相对URL!
我结合了前面的所有答案:
public static string UrlPathCombine(string path1, string path2)
{
path1 = path1.TrimEnd('/') + "/";
path2 = path2.TrimStart('/');
return Path.Combine(path1, path2)
.Replace(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
}
[TestMethod]
public void TestUrl()
{
const string P1 = "http://msdn.microsoft.com/slash/library//";
Assert.AreEqual("http://msdn.microsoft.com/slash/library/site.aspx", UrlPathCombine(P1, "//site.aspx"));
var path = UrlPathCombine("Http://MyUrl.com/", "Images/Image.jpg");
Assert.AreEqual(
"Http://MyUrl.com/Images/Image.jpg",
path);
}