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
有趣的例子,Ryan,以函数的链接结尾。做得好。
一个建议Brian:如果您将此代码包装在函数中,则可能需要在TryCreate调用之前使用UriBuilder包装基URL。
否则,基本URL必须包含方案(其中UriBuilder将采用http://)。只是一个想法:
public string CombineUrl(string baseUrl, string relativeUrl) {
UriBuilder baseUri = new UriBuilder(baseUrl);
Uri newUri;
if (Uri.TryCreate(baseUri.Uri, relativeUrl, out newUri))
return newUri.ToString();
else
throw new ArgumentException("Unable to combine specified url values");
}
其他回答
我发现UriBuilder在这种情况下工作得很好:
UriBuilder urlb = new UriBuilder("http", _serverAddress, _webPort, _filePath);
Uri url = urlb.Uri;
return url.AbsoluteUri;
有关更多构造函数和文档,请参阅UriBuilder类-MSDN。
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 |
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
我认为这应该给你更多的灵活性,因为你可以处理任意多的路径段:
public static string UrlCombine(this string baseUrl, params string[] segments)
=> string.Join("/", new[] { baseUrl.TrimEnd('/') }.Concat(segments.Select(s => s.Trim('/'))));
//阅读以上所有示例,结果创建了我自己:
static string UrlCombine(params string[] items)
{
if (items?.Any() != true)
{
return string.Empty;
}
return string.Join("/", items.Where(u => !string.IsNullOrWhiteSpace(u)).Select(u => u.Trim('/', '\\')));
}
//用法
UrlCombine("https://microsoft.com","en-us")