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
所以我有另一种方法,类似于使用UriBuilder的每个人。
我不想拆分我的BaseUrl(它可以包含路径的一部分,例如。http://mybaseurl.com/dev/)正如javajavajavajava所做的那样。
下面的代码片段显示了代码+测试。
注意:此解决方案降低了主机并附加了一个端口。如果不需要这样做,可以通过例如利用UriBuilder的Uri属性来编写字符串表示。
public class Tests
{
public static string CombineUrl (string baseUrl, string path)
{
var uriBuilder = new UriBuilder (baseUrl);
uriBuilder.Path = Path.Combine (uriBuilder.Path, path);
return uriBuilder.ToString();
}
[TestCase("http://MyUrl.com/", "/Images/Image.jpg", "http://myurl.com:80/Images/Image.jpg")]
[TestCase("http://MyUrl.com/basePath", "/Images/Image.jpg", "http://myurl.com:80/Images/Image.jpg")]
[TestCase("http://MyUrl.com/basePath", "Images/Image.jpg", "http://myurl.com:80/basePath/Images/Image.jpg")]
[TestCase("http://MyUrl.com/basePath/", "Images/Image.jpg", "http://myurl.com:80/basePath/Images/Image.jpg")]
public void Test1 (string baseUrl, string path, string expected)
{
var result = CombineUrl (baseUrl, path);
Assert.That (result, Is.EqualTo (expected));
}
}
在Windows 10上使用.NET Core 2.1进行测试。
为什么这样做?
尽管Path.Combine将返回反斜杠(至少在Windows上),但UriBuilder在路径设置器中处理这种情况。
摘自https://github.com/dotnet/corefx/blob/master/src/System.Private.Uri/src/System/UriBuilder.cs(注意调用字符串。替换)
[AllowNull]
public string Path
{
get
{
return _path;
}
set
{
if ((value == null) || (value.Length == 0))
{
value = "/";
}
_path = Uri.InternalEscapeString(value.Replace('\\', '/'));
_changed = true;
}
}
这是最好的方法吗?
当然,这个解决方案非常自我描述(至少在我看来)。但是,您依赖的是.NETAPI中的未记录(至少我在快速谷歌搜索中没有发现任何内容)“功能”。这可能会随着将来的版本而改变,因此请将方法与测试结合起来。
中有测试https://github.com/dotnet/corefx/blob/master/src/System.Private.Uri/tests/FunctionalTests/UriBuilderTests.cs(Path_Get_Set),用于检查\是否正确转换。
附带说明:如果Uri将用于System.Uri构造函数,则也可以直接使用UriBuilder.Uri属性。
其他回答
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);
}
如果任何人正在寻找一个单行,并且只想在不创建新方法或引用新库的情况下连接路径的一部分,或者构造URI值并将其转换为字符串,那么。。。
string urlToImage = String.Join("/", "websiteUrl", "folder1", "folder2", "folder3", "item");
这很基本,但我看不出你还需要什么。如果你害怕“/”加倍,那么你可以简单地在后面做一个替换(“//”,“/”)。如果您害怕替换“https://”中的双引号“//”,那么请执行一次连接,替换双引号“/”,然后加入网站url(但是我很确定大多数浏览器会自动将前面带有“https://的内容转换为正确格式)。这看起来像:
string urlToImage = String.Join("/","websiteUrl", String.Join("/", "folder1", "folder2", "folder3", "item").Replace("//","/"));
这里有很多答案可以解决以上所有问题,但在我的情况下,我只需要在一个地方使用一次,不需要过度依赖它。此外,很容易看到这里发生了什么。
参见:https://learn.microsoft.com/en-us/dotnet/api/system.string.join?view=netframework-4.8
Path.Combine对我不起作用,因为QueryString参数中可能有“|”这样的字符,因此URL也会出现ArgumentException。
我首先尝试了新的Uri(Uri-baseUri,string relativeUri)方法,但由于以下Uri而失败http://www.mediawiki.org/wiki/Special:SpecialPages:
new Uri(new Uri("http://www.mediawiki.org/wiki/"), "Special:SpecialPages")
将导致Special:SpecialPages,因为Special后面的冒号表示方案。
因此,我最终不得不采用mdsharpe/Brian MacKays路线,并进一步开发它,以处理多个URI部分:
public static string CombineUri(params string[] uriParts)
{
string uri = string.Empty;
if (uriParts != null && uriParts.Length > 0)
{
char[] trims = new char[] { '\\', '/' };
uri = (uriParts[0] ?? string.Empty).TrimEnd(trims);
for (int i = 1; i < uriParts.Length; i++)
{
uri = string.Format("{0}/{1}", uri.TrimEnd(trims), (uriParts[i] ?? string.Empty).TrimStart(trims));
}
}
return uri;
}
用法:CombineUri(“http://www.mediawiki.org/“,”wiki“,”Special:SpecialPages“)
我创建了这个功能,可以让您的生活更轻松:
/// <summary>
/// The ultimate Path combiner of all time
/// </summary>
/// <param name="IsURL">
/// true - if the paths are Internet URLs, false - if the paths are local URLs, this is very important as this will be used to decide which separator will be used.
/// </param>
/// <param name="IsRelative">Just adds the separator at the beginning</param>
/// <param name="IsFixInternal">Fix the paths from within (by removing duplicate separators and correcting the separators)</param>
/// <param name="parts">The paths to combine</param>
/// <returns>the combined path</returns>
public static string PathCombine(bool IsURL , bool IsRelative , bool IsFixInternal , params string[] parts)
{
if (parts == null || parts.Length == 0) return string.Empty;
char separator = IsURL ? '/' : '\\';
if (parts.Length == 1 && IsFixInternal)
{
string validsingle;
if (IsURL)
{
validsingle = parts[0].Replace('\\' , '/');
}
else
{
validsingle = parts[0].Replace('/' , '\\');
}
validsingle = validsingle.Trim(separator);
return (IsRelative ? separator.ToString() : string.Empty) + validsingle;
}
string final = parts
.Aggregate
(
(string first , string second) =>
{
string validfirst;
string validsecond;
if (IsURL)
{
validfirst = first.Replace('\\' , '/');
validsecond = second.Replace('\\' , '/');
}
else
{
validfirst = first.Replace('/' , '\\');
validsecond = second.Replace('/' , '\\');
}
var prefix = string.Empty;
if (IsFixInternal)
{
if (IsURL)
{
if (validfirst.Contains("://"))
{
var tofix = validfirst.Substring(validfirst.IndexOf("://") + 3);
prefix = validfirst.Replace(tofix , string.Empty).TrimStart(separator);
var tofixlist = tofix.Split(new[] { separator } , StringSplitOptions.RemoveEmptyEntries);
validfirst = separator + string.Join(separator.ToString() , tofixlist);
}
else
{
var firstlist = validfirst.Split(new[] { separator } , StringSplitOptions.RemoveEmptyEntries);
validfirst = string.Join(separator.ToString() , firstlist);
}
var secondlist = validsecond.Split(new[] { separator } , StringSplitOptions.RemoveEmptyEntries);
validsecond = string.Join(separator.ToString() , secondlist);
}
else
{
var firstlist = validfirst.Split(new[] { separator } , StringSplitOptions.RemoveEmptyEntries);
var secondlist = validsecond.Split(new[] { separator } , StringSplitOptions.RemoveEmptyEntries);
validfirst = string.Join(separator.ToString() , firstlist);
validsecond = string.Join(separator.ToString() , secondlist);
}
}
return prefix + validfirst.Trim(separator) + separator + validsecond.Trim(separator);
}
);
return (IsRelative ? separator.ToString() : string.Empty) + final;
}
它适用于URL和普通路径。
用法:
// Fixes internal paths
Console.WriteLine(PathCombine(true , true , true , @"\/\/folder 1\/\/\/\\/\folder2\///folder3\\/" , @"/\somefile.ext\/\//\"));
// Result: /folder 1/folder2/folder3/somefile.ext
// Doesn't fix internal paths
Console.WriteLine(PathCombine(true , true , false , @"\/\/folder 1\/\/\/\\/\folder2\///folder3\\/" , @"/\somefile.ext\/\//\"));
//result : /folder 1//////////folder2////folder3/somefile.ext
// Don't worry about URL prefixes when fixing internal paths
Console.WriteLine(PathCombine(true , false , true , @"/\/\/https:/\/\/\lul.com\/\/\/\\/\folder2\///folder3\\/" , @"/\somefile.ext\/\//\"));
// Result: https://lul.com/folder2/folder3/somefile.ext
Console.WriteLine(PathCombine(false , true , true , @"../../../\\..\...\./../somepath" , @"anotherpath"));
// Result: \..\..\..\..\...\.\..\somepath\anotherpath
我有一个无需分配的字符串创建版本,我一直在成功地使用它。
注:
对于第一个字符串:它使用TrimEnd(分隔符)修剪分隔符,因此仅从字符串的末尾开始。对于余数:它使用Trim(分隔符)修剪分隔符-因此路径的起点和终点都是它不附加尾部斜杠/分隔符。虽然可以做一个简单的修改来增加这个能力。
希望你觉得这很有用!
/// <summary>
/// This implements an allocation-free string creation to construct the path.
/// This uses 3.5x LESS memory and is 2x faster than some alternate methods (StringBuilder, interpolation, string.Concat, etc.).
/// </summary>
/// <param name="str"></param>
/// <param name="paths"></param>
/// <returns></returns>
public static string ConcatPath(this string str, params string[] paths)
{
const char separator = '/';
if (str == null) throw new ArgumentNullException(nameof(str));
var list = new List<ReadOnlyMemory<char>>();
var first = str.AsMemory().TrimEnd(separator);
// get length for intial string after it's trimmed
var length = first.Length;
list.Add(first);
foreach (var path in paths)
{
var newPath = path.AsMemory().Trim(separator);
length += newPath.Length + 1;
list.Add(newPath);
}
var newString = string.Create(length, list, (chars, state) =>
{
// NOTE: We don't access the 'list' variable in this delegate since
// it would cause a closure and allocation. Instead we access the state parameter.
// track our position within the string data we are populating
var position = 0;
// copy the first string data to index 0 of the Span<char>
state[0].Span.CopyTo(chars);
// update the position to the new length
position += state[0].Span.Length;
// start at index 1 when slicing
for (var i = 1; i < state.Count; i++)
{
// add a separator in the current position and increment position by 1
chars[position++] = separator;
// copy each path string to a slice at current position
state[i].Span.CopyTo(chars.Slice(position));
// update the position to the new length
position += state[i].Length;
}
});
return newString;
}
基准DotNet输出:
| Method | Mean | Error | StdDev | Median | Ratio | RatioSD | Gen 0 | Allocated |
|---------------------- |---------:|---------:|---------:|---------:|------:|--------:|-------:|----------:|
| ConcatPathWithBuilder | 404.1 ns | 27.35 ns | 78.48 ns | 380.3 ns | 1.00 | 0.00 | 0.3347 | 1,400 B |
| ConcatPath | 187.2 ns | 5.93 ns | 16.44 ns | 183.2 ns | 0.48 | 0.10 | 0.0956 | 400 B |