我正在使用custom class to expose some custom schema in Active Directory。我存储一个二进制blob,根据项目要求,这些数据必须存储在AD中,我不能使用外部存储(如果可以的话,我会这样做)。
当我创建用户时,它会保存blob。我也可以很好地检索blob并获取我的所有数据。问题是如果我需要更新值并且我收到错误
小例子程序:
using System;
using System.DirectoryServices.AccountManagement;
namespace SandboxConsole40
{
class Program
{
static void Main(string[] args)
{
using(var context = new PrincipalContext(ContextType.Domain))
{
using (var clear = ExamplePrincipal.FindByIdentity(context, "example"))
{
if (clear != null)
clear.Delete();
}
using (var create = new ExamplePrincipal(context, "example", "Password1", false))
{
create.Save();
}
using (var set = ExamplePrincipal.FindByIdentity(context, "example"))
{
set.BlobData = new byte[] { 0xDE, 0xAD, 0xBE, 0xEF }; //This fails with method 2.
set.Save();
}
using (var lookup = ExamplePrincipal.FindByIdentity(context, "example"))
{
Console.WriteLine(BitConverter.ToString(lookup.BlobData));
}
using (var update = ExamplePrincipal.FindByIdentity(context, "example"))
{
update.BlobData = new byte[] { 0x12, 0x34, 0x56, 0x67 };
update.Save(); //This save fails with method 1.
}
}
Console.WriteLine("Done");
Console.ReadLine();
}
[DirectoryObjectClass("user")]
[DirectoryRdnPrefix("CN")]
class ExamplePrincipal : UserPrincipal
{
public ExamplePrincipal(PrincipalContext context) : base(context) { }
public ExamplePrincipal(PrincipalContext context, string samAccountName, string password, bool enabled)
: base(context, samAccountName, password, enabled) { }
public static new ExamplePrincipal FindByIdentity(PrincipalContext context, string identityValue)
{
return (ExamplePrincipal)FindByIdentityWithType(context, typeof(ExamplePrincipal), identityValue);
}
[DirectoryProperty("vwBlobData")]
public byte[] BlobData
{
get
{
if (ExtensionGet("vwBlobData").Length != 1)
return null;
return (byte[])ExtensionGet("vwBlobData")[0];
}
set
{
//method 1
this.ExtensionSet("vwBlobData", value );
//method 2
//this.ExtensionSet("vwBlobData", new object[] { value});
}
}
}
}
}
如果我使用方法1,我在update.Save()
操作
System.DirectoryServices.AccountManagement.PrincipalOperationException was unhandled HResult=-2146233087 Message=The specified directory service attribute or value already exists. Source=System.DirectoryServices.AccountManagement ErrorCode=-2147016691 StackTrace: //Snip InnerException: System.DirectoryServices.DirectoryServicesCOMException HResult=-2147016691 Message=The specified directory service attribute or value already exists. Source=System.DirectoryServices ErrorCode=-2147016691 ExtendedError=8321 ExtendedErrorMessage=00002081: AtrErr: DSID-030F154F, #1: 0: 00002081: DSID-030F154F, problem 1006 (ATT_OR_VALUE_EXISTS), data 0, Att 82818fec (vwBlobData) StackTrace: //Snip InnerException:
如果我使用方法2,我会从this.ExtensionSet
来电的set.BlobData
来电中获得例外。
System.ArgumentException was unhandled HResult=-2147024809 Message=Collections whose elements are another collection cannot be set by ExtensionClasses. Source=System.DirectoryServices.AccountManagement StackTrace: //Snip InnerException:
总结:我可以设置当前未设置的值,但如果我想覆盖现有值,则会收到错误。
答案 0 :(得分:3)
我找到了一个解决办法,首先将值设置为null,不再抛出异常。
using (var update = ExamplePrincipal.FindByIdentity(context, "example"))
{
update.BlobData = null;
update.Save();
update.BlobData = new byte[] { 0x12, 0x34, 0x56, 0x67 };
update.Save(); //No longer fails with method 1.
}
如果有一个“正确”的方式,我会暂时搁置这个问题以确定是否有其他人可以回答。
找到第二个解决方案,不需要强制保存。
[DirectoryProperty("vwBlobData")]
public byte[] BlobData
{
get
{
if (ExtensionGet("vwBlobData").Length != 1)
return null;
return (byte[])ExtensionGet("vwBlobData")[0];
}
set
{
((DirectoryEntry)this.GetUnderlyingObject())
.Properties["vwBlobData"].Value = value;
}
}
通过直接转换为基础对象,您可以直接设置值。我使用ILSpy检查并处理AccountManagement包装器处理底层对象,因此Dispose()
调用不需要GetUnderlyingObject()
。
最佳解决方案
我发现第二个工作需要将对象保持工作,所以我采用了两种方法。当你还没有持久化对象,当对象为null,以及对象已经有值时,这种方法有效。
[DirectoryProperty("vwBlobData")]
public byte[] BlobData
{
get
{
if (ExtensionGet("vwBlobData").Length != 1)
return null;
return (byte[])ExtensionGet("vwBlobData")[0];
}
set
{
if(ExtensionGet("vwBlobData").Length == 0)
this.ExtensionSet("vwBlobData", data);
else
((DirectoryEntry)this.GetUnderlyingObject())
.Properties["vwBlobData"].Value = data;
}
}