你可以使用

Uri。EscapeUriString(参见http://msdn.microsoft.com/en-us/library/system.uri.escapeuristring.aspx)

在.Net 4.5+中使用WebUtility

只是为了格式，我把这个作为答案提交。

我找不到任何比较它们的例子，所以:

string testString = "http://test# space 123/text?var=val&another=two";
Console.WriteLine("UrlEncode:         " + System.Web.HttpUtility.UrlEncode(testString));
Console.WriteLine("EscapeUriString:   " + Uri.EscapeUriString(testString));
Console.WriteLine("EscapeDataString:  " + Uri.EscapeDataString(testString));
Console.WriteLine("EscapeDataReplace: " + Uri.EscapeDataString(testString).Replace("%20", "+"));

Console.WriteLine("HtmlEncode:        " + System.Web.HttpUtility.HtmlEncode(testString));
Console.WriteLine("UrlPathEncode:     " + System.Web.HttpUtility.UrlPathEncode(testString));

//.Net 4.0+
Console.WriteLine("WebUtility.HtmlEncode: " + WebUtility.HtmlEncode(testString));
//.Net 4.5+
Console.WriteLine("WebUtility.UrlEncode:  " + WebUtility.UrlEncode(testString));

输出:

UrlEncode:             http%3a%2f%2ftest%23+space+123%2ftext%3fvar%3dval%26another%3dtwo
EscapeUriString:       http://test#%20space%20123/text?var=val&another=two
EscapeDataString:      http%3A%2F%2Ftest%23%20space%20123%2Ftext%3Fvar%3Dval%26another%3Dtwo
EscapeDataReplace:     http%3A%2F%2Ftest%23+space+123%2Ftext%3Fvar%3Dval%26another%3Dtwo

HtmlEncode:            http://test# space 123/text?var=val&another=two
UrlPathEncode:         http://test#%20space%20123/text?var=val&another=two

//.Net 4.0+
WebUtility.HtmlEncode: http://test# space 123/text?var=val&another=two
//.Net 4.5+
WebUtility.UrlEncode:  http%3A%2F%2Ftest%23+space+123%2Ftext%3Fvar%3Dval%26another%3Dtwo

在. net 4.5+中使用WebUtility。UrlEncode

这似乎复制了HttpUtility。UrlEncode (v4.0之前)用于更常见的字符: Uri.EscapeDataString (testString)。替换(“% 20”,“+”)。替换(“”、“”)。替换(“~”,“% 7 e”) 注意:EscapeUriString将保留一个有效的uri字符串，这将导致它使用尽可能多的明文字符。

请参阅比较各种编码的表格的答案: https://stackoverflow.com/a/11236038/555798

换行符 这里列出的所有代码(HttpUtility.HtmlEncode除外)都将“\n\r”转换为%0a%0d或%0a%0d

请随意编辑，并向我的测试字符串中添加新字符，或将它们留在评论中，我会编辑它。

下面是一个发送POST请求的例子，使用application/x-www-form-urlencoded内容类型正确编码参数:

using (var client = new WebClient())
{
    var values = new NameValueCollection
    {
        { "param1", "value1" },
        { "param2", "value2" },
    };
    var result = client.UploadValues("http://foo.com", values);
}

这里的答案很好，但对我来说仍然不够。

我写了一个比较Uri的小循环。带Uri的EscapeUriString。为0到255的所有字符提供EscapeDataString。

注意:这两个函数都具有内置智能，即0x80以上的字符首先被UTF-8编码，然后被百分比编码。

结果如下:

******* Different *******

'#' -> Uri "#" Data "%23"
'$' -> Uri "$" Data "%24"
'&' -> Uri "&" Data "%26"
'+' -> Uri "+" Data "%2B"
',' -> Uri "," Data "%2C"
'/' -> Uri "/" Data "%2F"
':' -> Uri ":" Data "%3A"
';' -> Uri ";" Data "%3B"
'=' -> Uri "=" Data "%3D"
'?' -> Uri "?" Data "%3F"
'@' -> Uri "@" Data "%40"


******* Not escaped *******

'!' -> Uri "!" Data "!"
''' -> Uri "'" Data "'"
'(' -> Uri "(" Data "("
')' -> Uri ")" Data ")"
'*' -> Uri "*" Data "*"
'-' -> Uri "-" Data "-"
'.' -> Uri "." Data "."
'_' -> Uri "_" Data "_"
'~' -> Uri "~" Data "~"

'0' -> Uri "0" Data "0"
.....
'9' -> Uri "9" Data "9"

'A' -> Uri "A" Data "A"
......
'Z' -> Uri "Z" Data "Z"

'a' -> Uri "a" Data "a"
.....
'z' -> Uri "z" Data "z"

******* UTF 8 *******

.....
'Ò' -> Uri "%C3%92" Data "%C3%92"
'Ó' -> Uri "%C3%93" Data "%C3%93"
'Ô' -> Uri "%C3%94" Data "%C3%94"
'Õ' -> Uri "%C3%95" Data "%C3%95"
'Ö' -> Uri "%C3%96" Data "%C3%96"
.....

EscapeUriString用于编码url，而EscapeDataString用于编码例如Cookie的内容，因为Cookie数据不能包含保留字符'='和';'。

System.Net.WebUtility.HtmlDecode

你可以使用

Uri。EscapeUriString(参见http://msdn.microsoft.com/en-us/library/system.uri.escapeuristring.aspx)