当两个程序集具有相同的命名空间时，如何解决 'Cannot implicitly convert' 错误？

Question

我正在编写证书生成程序，但我遇到了类似 BouncyCastle 和 ITextSharp-LGPL-4.1.6 之间的程序集命名空间冲突的问题。

所以我尝试为我正在使用的 BouncyCastle 库添加一个别名，并尝试显式转换，但没有任何效果。

return (BouncyCastleCrypto::Org.BouncyCastle.X509.X509Certificate)cert.Generate(pair.Private);

结果是我得到一个错误：

CS0029 Cannot implicitly convert type 'Org.BouncyCastle.X509.X509Certificate [C:\XXX\packages\BouncyCastle.1.8.4\lib\BouncyCastle.Crypto.dll]' to 'Org.BouncyCastle.X509.X509Certificate [C:\XXX\packages\iTextSharp-LGPL.4.1.6\lib\iTextSharp.dll]' Project C:\xxx\src\MyCode.cs

我现在不知道该怎么办，我别无选择。

编辑 1：

问题不是关于访问类型本身，而是关于调用类型的方法。

我有这部分代码：

BouncyCastleCrypto::Org.BouncyCastle.X509.X509V3CertificateGenerator cert = new BouncyCastleCrypto::Org.BouncyCastle.X509.X509V3CertificateGenerator();

然后我有这部分代码：

return cert.Generate(pair.Private);

这给了我错误。当这只是方法调用时，我应该如何澄清我使用的是哪个程序集？

编辑2：

好的，我将整个文件粘贴到这里：

extern alias BouncyCastleCrypto;
using BouncyCastleCrypto.Org.BouncyCastle.Crypto.Operators;
using BouncyCastleCrypto.Org.BouncyCastle.Asn1.Pkcs;
using BouncyCastleCrypto.Org.BouncyCastle.Asn1.X509;
using BouncyCastleCrypto.Org.BouncyCastle.Crypto;
using BouncyCastleCrypto.Org.BouncyCastle.Crypto.Generators;
using BouncyCastleCrypto.Org.BouncyCastle.Crypto.Prng;
using BouncyCastleCrypto.Org.BouncyCastle.OpenSsl;
using BouncyCastleCrypto.Org.BouncyCastle.Pkcs;
using BouncyCastleCrypto.Org.BouncyCastle.Security;
using XXXX.ViewModels;
using System;
using System.Collections;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using BouncyCastleCrypto.Org.BouncyCastle.X509;
using BouncyCastleCrypto.Org.BouncyCastle.Math;

namespace XXXX.Helpers
{
  public static class PKIHelper
  {


public static Org.BouncyCastle.X509.X509Certificate GenCert(CertInfo info)
{
  RsaKeyPairGenerator _rsa = new RsaKeyPairGenerator();
  SecureRandom _random = new SecureRandom();

  _rsa.Init(new KeyGenerationParameters(_random, info.rsa_strength));
  AsymmetricCipherKeyPair _pair = _rsa.GenerateKeyPair();

  X509Name _cert_name = new X509Name("CN=" + info.name);
  BigInteger _serialnumber = BigInteger.ProbablePrime(120, new Random());

  BouncyCastleCrypto::Org.BouncyCastle.X509.X509V3CertificateGenerator _cert = new BouncyCastleCrypto::Org.BouncyCastle.X509.X509V3CertificateGenerator();
  _cert.SetSerialNumber(_serialnumber);
  _cert.SetSubjectDN(_cert_name);
  _cert.SetIssuerDN(_cert_name);
  _cert.SetNotBefore(info.begin_date);
  _cert.SetNotAfter(info.expire_date);
  _cert.SetSignatureAlgorithm("SHA1withRSA");
  _cert.SetPublicKey(_pair.Public);

  _cert.AddExtension(X509Extensions.ExtendedKeyUsage.Id, false,
      new AuthorityKeyIdentifier(
          SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(_pair.Public),
          new GeneralNames(new GeneralName(_cert_name)), _serialnumber));
  _cert.AddExtension(X509Extensions.ExtendedKeyUsage.Id, false,
      new ExtendedKeyUsage(new[] { KeyPurposeID.IdKPServerAuth }));


  return _cert.Generate(_pair.Private); // here's error
}

  }
}

Answer 1

好吧，我很确定我使用的 return 类型是 GeneratePKI 方法的正确类型，即 Org.BouncyCastle.X509.X509Certificate，但实际上 Org.BouncyCastle.X509.X509Certificate 来自 iTextSharp 库，因此编译器认为它必须隐式地转换它。当我在方法 return 类型 BouncyCastleCrypto::Org.BouncyCastle.X509.X509Certificate 之前添加别名时，它神奇地再次开始编译。感谢@devNull，没有抛弃我。

当两个程序集具有相同的命名空间时，如何解决 'Cannot implicitly convert' 错误？

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