.NET Core中如何对Url进行编码和解码

我们在.NET Core项目中，可以用WebUtility类对Url进行编码和解码，首先我们要确保项目中引入了nuget包：System.Runtime.Extensions

当然这个nuget包默认就是包含在.NET Core的核心库中的，所以正常情况下不用单独去引入。

我们来看看WebUtility类的定义：

using System.IO;

namespace System.Net
{
    //
    // 摘要:
    //     Provides methods for encoding and decoding URLs when processing Web requests.
    public static class WebUtility
    {
        //
        // 摘要:
        //     Converts a string that has been HTML-encoded for HTTP transmission into a decoded
        //     string.
        //
        // 参数:
        //   value:
        //     The string to decode.
        //
        // 返回结果:
        //     A decoded string.
        public static string HtmlDecode(string value);
        //
        // 摘要:
        //     Converts a string that has been HTML-encoded into a decoded string, and sends
        //     the decoded string to a System.IO.TextWriter output stream.
        //
        // 参数:
        //   value:
        //     The string to decode.
        //
        //   output:
        //     A System.IO.TextWriter stream of output.
        //
        // 异常:
        //   T:System.ArgumentNullException:
        //     The output parameter cannot be null if the value parameter is not null.
        public static void HtmlDecode(string value, TextWriter output);
        //
        // 摘要:
        //     Converts a string to an HTML-encoded string.
        //
        // 参数:
        //   value:
        //     The string to encode.
        //
        // 返回结果:
        //     An encoded string.
        public static string HtmlEncode(string value);
        //
        // 摘要:
        //     Converts a string into an HTML-encoded string, and returns the output as a System.IO.TextWriter
        //     stream of output.
        //
        // 参数:
        //   value:
        //     The string to encode.
        //
        //   output:
        //     A System.IO.TextWriter output stream.
        //
        // 异常:
        //   T:System.ArgumentNullException:
        //     The output parameter cannot be null if the value parameter is not null.
        public static void HtmlEncode(string value, TextWriter output);
        //
        // 摘要:
        //     Converts a string that has been encoded for transmission in a URL into a decoded
        //     string.
        //
        // 参数:
        //   encodedValue:
        //     A URL-encoded string to decode.
        //
        // 返回结果:
        //     Returns System.String. A decoded string.
        public static string UrlDecode(string encodedValue);
        //
        // 摘要:
        //     Converts an encoded byte array that has been encoded for transmission in a URL
        //     into a decoded byte array.
        //
        // 参数:
        //   encodedValue:
        //     A URL-encoded System.Byte array to decode.
        //
        //   offset:
        //     The offset, in bytes, from the start of the System.Byte array to decode.
        //
        //   count:
        //     The count, in bytes, to decode from the System.Byte array.
        //
        // 返回结果:
        //     Returns System.Byte. A decoded System.Byte array.
        public static byte[] UrlDecodeToBytes(byte[] encodedValue, int offset, int count);
        //
        // 摘要:
        //     Converts a text string into a URL-encoded string.
        //
        // 参数:
        //   value:
        //     The text to URL-encode.
        //
        // 返回结果:
        //     Returns System.String. A URL-encoded string.
        public static string UrlEncode(string value);
        //
        // 摘要:
        //     Converts a byte array into a URL-encoded byte array.
        //
        // 参数:
        //   value:
        //     The System.Byte array to URL-encode.
        //
        //   offset:
        //     The offset, in bytes, from the start of the System.Byte array to encode.
        //
        //   count:
        //     The count, in bytes, to encode from the System.Byte array.
        //
        // 返回结果:
        //     Returns System.Byte. An encoded System.Byte array.
        public static byte[] UrlEncodeToBytes(byte[] value, int offset, int count);
    }
}

现在我们新建一个.NET Core控制台项目，来演示WebUtility类的简单用法，代码如下：

using System;
using System.Net;

namespace WebUtilDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            string rawUri = "http://localhost:8989/home/index";

            Console.WriteLine($"原始Uri地址是：{rawUri}");

            string encodedUri = WebUtility.UrlEncode(rawUri);

            Console.WriteLine($"编码后Uri地址是：{encodedUri}");//http%3A%2F%2Flocalhost%3A8989%2Fhome%2Findex

            string decodedUri = WebUtility.UrlDecode(encodedUri);

            Console.WriteLine($"解码后Uri地址是：{decodedUri}");//http://localhost:8989/home/index

            Console.WriteLine("按任意键退出...");
            Console.ReadKey();
        }
    }
}

程序运行结果如下：

所以我们看到在.NET Core中使用WebUtility类，可以很方便地对Url进行编码和解码。