如何在RemoteCertificateValidationCallback委托中传递MyObject对象

我有一个MethodA方法，会在其中创建一个对象：

private void MethodA()
{
  MyObject myObject = new MyObject();

  try
  {
    ServicePointManager.ServerCertificateValidationCallback += MethodB;
    // some logic
  }
  catch(Exception ex) 
  {
    // some handling
  }
  finally
  {
    // some logic
    ServicePointManager.ServerCertificateValidationCallback -= MethodB;
  }
}

在我的MethodB方法中，需要获取这个MyObject实例：

private bool MethodB(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{
  // 需要在这里访问MyObject
}

请问有没有正确的实现方式？

方法一：利用闭包捕获变量 #

直接用lambda表达式替代独立的MethodB，借助C#闭包特性直接访问myObject，同时可以把验证逻辑抽成独立方法保持代码整洁：

private void MethodA()
{
  MyObject myObject = new MyObject();
  // 定义捕获myObject的验证回调
  RemoteCertificateValidationCallback validationCallback = (sender, cert, chain, errors) =>
  {
    // 直接访问myObject
    Console.WriteLine(myObject.SomeProperty);
    // 调用抽离的验证逻辑方法
    return ValidateCertificate(myObject, sender, cert, chain, errors);
  };

  try
  {
    ServicePointManager.ServerCertificateValidationCallback += validationCallback;
    // some logic
  }
  catch(Exception ex) 
  {
    // some handling
  }
  finally
  {
    ServicePointManager.ServerCertificateValidationCallback -= validationCallback;
  }
}

// 抽离原MethodB的逻辑，接收MyObject参数
private bool ValidateCertificate(MyObject myObject, object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{
  // 在这里使用myObject处理验证逻辑
  return true; // 根据实际需求返回验证结果
}

这种方式简单直接，无需额外状态管理，适合大多数场景。

方法二：通过请求对象的属性传递（适用于HttpWebRequest场景） #

如果你的业务逻辑基于HttpWebRequest，回调的sender参数通常就是该请求实例，可以把myObject存入请求的自定义属性中：

private void MethodA()
{
  MyObject myObject = new MyObject();
  // 创建请求实例
  HttpWebRequest request = WebRequest.Create("https://example.com") as HttpWebRequest;
  // 将myObject存入请求的自定义属性集合
  request.Properties["MyObjectKey"] = myObject;

  try
  {
    ServicePointManager.ServerCertificateValidationCallback += MethodB;
    // 执行请求发送等逻辑
    using (var response = request.GetResponse() as HttpWebResponse)
    {
      // 处理响应
    }
  }
  catch(Exception ex) 
  {
    // some handling
  }
  finally
  {
    ServicePointManager.ServerCertificateValidationCallback -= MethodB;
  }
}

private bool MethodB(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{
  if (sender is HttpWebRequest request)
  {
    // 从请求属性中取出MyObject
    if (request.Properties.TryGetValue("MyObjectKey", out var obj) && obj is MyObject myObject)
    {
      // 使用myObject处理逻辑
      Console.WriteLine(myObject.SomeProperty);
    }
  }
  // 执行验证逻辑
  return true;
}

注意：该方法依赖sender的具体类型，仅当回调触发时sender是你可控的请求对象时生效。

方法三：自定义封装类管理状态 #

创建专门的验证器类，封装MyObject实例和验证逻辑，避免闭包可能带来的生命周期混淆：

// 自定义验证器类，保存需要的MyObject实例
private class CertificateValidator
{
  private readonly MyObject _myObject;

  public CertificateValidator(MyObject myObject)
  {
    _myObject = myObject;
  }

  // 验证方法，包含原MethodB的逻辑
  public bool Validate(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
  {
    // 直接使用_myObject
    Console.WriteLine(_myObject.SomeProperty);
    // 执行验证逻辑
    return true;
  }
}

private void MethodA()
{
  MyObject myObject = new MyObject();
  var validator = new CertificateValidator(myObject);

  try
  {
    ServicePointManager.ServerCertificateValidationCallback += validator.Validate;
    // some logic
  }
  catch(Exception ex) 
  {
    // some handling
  }
  finally
  {
    ServicePointManager.ServerCertificateValidationCallback -= validator.Validate;
  }
}

这种方式状态管理更清晰，适合复杂业务场景下的逻辑拆分。

内容的提问来源于stack exchange，提问作者Sara Mannings