C# 指向 base64 的指南，用于 URL
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guid to base64, for URL
提问by Fredou
Question: is there a better way to do that?
问题：有没有更好的方法来做到这一点？
VB.Net
VB.Net
Function GuidToBase64(ByVal guid As Guid) As String
Return Convert.ToBase64String(guid.ToByteArray).Replace("/", "-").Replace("+", "_").Replace("=", "")
End Function
Function Base64ToGuid(ByVal base64 As String) As Guid
Dim guid As Guid
base64 = base64.Replace("-", "/").Replace("_", "+") & "=="
Try
guid = New Guid(Convert.FromBase64String(base64))
Catch ex As Exception
Throw New Exception("Bad Base64 conversion to GUID", ex)
End Try
Return guid
End Function
C#
C＃
public string GuidToBase64(Guid guid)
{
return Convert.ToBase64String(guid.ToByteArray()).Replace("/", "-").Replace("+", "_").Replace("=", "");
}
public Guid Base64ToGuid(string base64)
{
Guid guid = default(Guid);
base64 = base64.Replace("-", "/").Replace("_", "+") + "==";
try {
guid = new Guid(Convert.FromBase64String(base64));
}
catch (Exception ex) {
throw new Exception("Bad Base64 conversion to GUID", ex);
}
return guid;
}
采纳答案by Hemant
I understand that the reason you are clipping == in the end is that because you can be certain that for GUID (of 16 bytes), encoded string will alwaysend with ==. So 2 characters can be saved in every conversion.
我知道您最终剪裁 == 的原因是因为您可以确定对于 GUID（16 个字节），编码字符串将始终以 == 结尾。所以每次转换可以保存 2 个字符。
Beside the point @Skurmedal already mentioned (should throw an exception in case of invalid string as input), I think the code you posted is just good enough.
除了@Skurmedal 已经提到的点（在输入无效字符串的情况下应该抛出异常）之外，我认为您发布的代码已经足够好了。
回答by Skurmedel
If your method cannot convert the Base64 passed to it to a GUID, shouldn't you throw an exception? The data passed to the method is clearly erronous.
如果您的方法无法将传递给它的 Base64 转换为 GUID，您不应该抛出异常吗？传递给方法的数据显然是错误的。
回答by JamesBrownIsDead
You might want to check out this site: http://prettycode.org/2009/11/12/short-guid/
你可能想看看这个网站：http: //prettycode.org/2009/11/12/short-guid/
It looks very close to what you're doing.
它看起来非常接近你正在做的事情。
public class ShortGuid
{
private readonly Guid guid;
private readonly string value;
/// <summary>Create a 22-character case-sensitive short GUID.</summary>
public ShortGuid(Guid guid)
{
if (guid == null)
{
throw new ArgumentNullException("guid");
}
this.guid = guid;
this.value = Convert.ToBase64String(guid.ToByteArray())
.Substring(0, 22)
.Replace("/", "_")
.Replace("+", "-");
}
/// <summary>Get the short GUID as a string.</summary>
public override string ToString()
{
return this.value;
}
/// <summary>Get the Guid object from which the short GUID was created.</summary>
public Guid ToGuid()
{
return this.guid;
}
/// <summary>Get a short GUID as a Guid object.</summary>
/// <exception cref="System.ArgumentNullException"></exception>
/// <exception cref="System.FormatException"></exception>
public static ShortGuid Parse(string shortGuid)
{
if (shortGuid == null)
{
throw new ArgumentNullException("shortGuid");
}
else if (shortGuid.Length != 22)
{
throw new FormatException("Input string was not in a correct format.");
}
return new ShortGuid(new Guid(Convert.FromBase64String
(shortGuid.Replace("_", "/").Replace("-", "+") + "==")));
}
public static implicit operator String(ShortGuid guid)
{
return guid.ToString();
}
public static implicit operator Guid(ShortGuid shortGuid)
{
return shortGuid.guid;
}
}
回答by Joe
One problem with using this technique to format a GUID for use in a URL or filename is that two distinct GUIDs can produce two values that differ only in case, e.g.:
使用这种技术来格式化用于 URL 或文件名的 GUID 的一个问题是，两个不同的 GUID 可以产生两个仅在大小写上不同的值，例如：
var b1 = GuidToBase64(new Guid("c9d045f3-e21c-46d0-971d-b92ebc2ab83c"));
var b2 = GuidToBase64(new Guid("c9d045f3-e21c-46d0-971d-b92ebc2ab8a4"));
Console.WriteLine(b1); // 80XQyRzi0EaXHbkuvCq4PA
Console.WriteLine(b2); // 80XQyRzi0EaXHbkuvCq4pA
Since URLs are sometimes interpreted as being case-insensitive, and in Windows file paths and filenames are case-insensitive. this could lead to collisions.
由于 URL 有时被解释为不区分大小写，并且在 Windows 中文件路径和文件名不区分大小写。这可能会导致碰撞。
