如何对base64字符串进行编码和解码?

1. How do I return a base64 encoded string given a string?

   如何返回一个给定字符串的base64编码的字符串?

2. How do I decode a base64 encoded string into a string?

   如何将base64编码的字符串解码成字符串?

4 个解决方案

#1

Encode

public static string Base64Encode(string plainText) {
  var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);
  return System.Convert.ToBase64String(plainTextBytes);
}

Decode

public static string Base64Decode(string base64EncodedData) {
  var base64EncodedBytes = System.Convert.FromBase64String(base64EncodedData);
  return System.Text.Encoding.UTF8.GetString(base64EncodedBytes);
}

#2

I'm sharing my implementation with some neat features:

我将我的实现与一些整洁的特性共享:

• uses Extension Methods for Encoding class. Rationale is that someone may need to support different types of encodings (not only UTF8).
• 使用扩展方法来编码类。基本原理是有人可能需要支持不同类型的编码(不仅仅是UTF8)。
• Another improvement is failing gracefully with null result for null entry - it's very useful in real life scenarios and supports equivalence for X=decode(encode(X)).
• 另一个改进是零输入的空结果很优雅地失败——它在现实生活场景中非常有用，并且支持X=decode(encode(X))的等价性。

Remark: Remember that to use Extension Method you have to (!) import the namespace with using keyword (in this case using MyApplication.Helpers.Encoding).

注意:要使用扩展方法，必须使用关键字(在本例中使用myapplication . helperson . encoding)导入名称空间。

Code:

代码:

namespace MyApplication.Helpers.Encoding
{
    public static class EncodingForBase64
    {
        public static string EncodeBase64(this System.Text.Encoding encoding, string text)
        {
            if (text == null)
            {
                return null;
            }

            byte[] textAsBytes = encoding.GetBytes(text);
            return System.Convert.ToBase64String(textAsBytes);
        }

        public static string DecodeBase64(this System.Text.Encoding encoding, string encodedText)
        {
            if (encodedText == null)
            {
                return null;
            }

            byte[] textAsBytes = System.Convert.FromBase64String(encodedText);
            return encoding.GetString(textAsBytes);
        }
    }
}

Usage example:

使用的例子:

using MyApplication.Helpers.Encoding; // !!!

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Test1();
            Test2();
        }

        static void Test1()
        {
            string textEncoded = System.Text.Encoding.UTF8.EncodeBase64("test1...");
            System.Diagnostics.Debug.Assert(textEncoded == "dGVzdDEuLi4=");

            string textDecoded = System.Text.Encoding.UTF8.DecodeBase64(textEncoded);
            System.Diagnostics.Debug.Assert(textDecoded == "test1...");
        }

        static void Test2()
        {
            string textEncoded = System.Text.Encoding.UTF8.EncodeBase64(null);
            System.Diagnostics.Debug.Assert(textEncoded == null);

            string textDecoded = System.Text.Encoding.UTF8.DecodeBase64(textEncoded);
            System.Diagnostics.Debug.Assert(textDecoded == null);
        }
    }
}

#3

A slight variation on andrew.fox answer, as the string to decode might not be a correct base64 encoded string:

安德鲁稍有不同。狐狸回答，因为要解码的字符串可能不是正确的base64编码的字符串:

using System;

namespace Service.Support
{
    public static class Base64
    {
        public static string ToBase64(this System.Text.Encoding encoding, string text)
        {
            if (text == null)
            {
                return null;
            }

            byte[] textAsBytes = encoding.GetBytes(text);
            return Convert.ToBase64String(textAsBytes);
        }

        public static bool TryParseBase64(this System.Text.Encoding encoding, string encodedText, out string decodedText)
        {
            if (encodedText == null)
            {
                decodedText = null;
                return false;
            }

            try
            {
                byte[] textAsBytes = Convert.FromBase64String(encodedText);
                decodedText = encoding.GetString(textAsBytes);
                return true;
            }
            catch (Exception)
            {
                decodedText = null;
                return false;   
            }
        }
    }
}

#4

Based on the answers by Andrew Fox and Cebe, I turned it around and made them string extensions instead of Base64String extensions.

根据Andrew Fox和Cebe的回答，我将它翻转过来，使它们成为字符串扩展，而不是Base64String扩展。

    public static class StringExtensions
    {
        public static string ToBase64(this string text)
        {
            return ToBase64(text, Encoding.UTF8);
        }

        public static string ToBase64(this string text, Encoding encoding)
        {
            if (string.IsNullOrEmpty(text))
            {
                return text;
            }

            byte[] textAsBytes = encoding.GetBytes(text);
            return Convert.ToBase64String(textAsBytes);
        }

        public static bool TryParseBase64(this string text, out string decodedText)
        {
            return TryParseBase64(text, Encoding.UTF8, out decodedText);
        }

        public static bool TryParseBase64(this string text, Encoding encoding, out string decodedText)
        {
            if (string.IsNullOrEmpty(text))
            {
                decodedText = text;
                return false;
            }

            try
            {
                byte[] textAsBytes = Convert.FromBase64String(text);
                decodedText = encoding.GetString(textAsBytes);
                return true;
            }
            catch (Exception)
            {
                decodedText = null;
                return false;
            }
        }
    }