关于c＃：引导到base64，用于URL

guid to base64, for URL

问题：有更好的方法吗？

VB.Net

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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＃

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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;
}

相关讨论

您可能想查看以下站点：http://prettycode.org/2009/11/12/short-guid/

它看起来非常接近您的工作。

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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;
}
}

使用此技术来格式化用于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不同的值，例如：

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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

由于有时将URL解释为不区分大小写，因此在Windows中，文件路径和文件名不区分大小写。这可能导致碰撞。

相关讨论

我知道最后剪切==的原因是因为可以确定对于GUID(16字节)，编码字符串将始终以==结尾。因此，每次转换可以保存2个字符。

除了已经提到的@Skurmedal问题(如果输入的字符串无效，应该抛出异常)，我认为您发布的代码就足够了。

相关讨论

如果您的方法无法将传递给它的Base64转换为GUID，您是否应该引发异常？传递给该方法的数据显然是错误的。

相关讨论