这是常见的只需简单更换字母的在URL中使用，所以没有％编码是必要的;只有65个字符的3是有问题的 - + ， / 和 = 。最常见的替代品是 - 在 + 和 _ 的>在 / 的。至于填充：只是将其删除的（即 = ）;你可以的推断的需要填充量。在另一端：刚刚相反的过程：

It is common to simply swap alphabet for use in urls, so that no %-encoding is necessary; only 3 of the 65 characters are problematic - +, / and =. the most common replacements are - in place of + and _ in place of /. As for the padding: just remove it (the =); you can infer the amount of padding needed. At the other end: just reverse the process:

string returnValue = System.Convert.ToBase64String(toEncodeAsBytes)
        .TrimEnd(padding).Replace('+', '-').Replace('/', '_');

与

static readonly char[] padding = { '=' };

和扭转：

string incoming = returnValue
    .Replace('_', '/').Replace('-', '+');
switch(returnValue.Length % 4) {
    case 2: incoming += "=="; break;
    case 3: incoming += "="; break;
}
byte[] bytes = Convert.FromBase64String(incoming);
string originalText = Encoding.ASCII.GetString(bytes);

有趣的问题，但是，是：这是相同的做法，即共同codeC图书馆使用的这肯定会是测试一个合理的第一件事情 - 这是一个pretty常用的方法。

The interesting question, however, is: is this the same approach that the "common codec library" uses? It would certainly be a reasonable first thing to test - this is a pretty common approach.