.NET:将对象从第 3 方程序集序列化为文件(以使 Selenium WebDriver 更快)

Question

序列化 FirefoxDriver 的最终目标(我的问题在这里)= 使 WebDriver 更快!!

下面是描述如何序列化对象的链接。但它需要您从 ISerializable 为您正在序列化的对象实现。我想做的是序列化一个我没有定义的对象——一个基于第 3 方程序集(来自项目引用)中的类的对象，即 。未实现 ISerializable .那可能吗？如何才能做到这一点？

http://www.switchonthecode.com/tutorials/csharp-tutorial-serialize-objects-to-a-file

属性(IWebDriver = 接口(interface)类型):

private IWebDriver driver;

对象实例(FireFoxDriver 是类类型):

driver = new FirefoxDriver(firefoxProfile);

=================

2012 年 3 月 21 日发布答案后更新

为什么这会引发错误？它不喜欢这一行:

serializedObject.DriverInstance = (FirefoxDriver)driver;

...

错误:

Cannot implicitly convert type 'OpenQA.Selenium.IWebDriver' to 'OpenQA.Selenium.Firefox.FirefoxDriver'. An explicit conversion exists (are you missing a cast?)

这是代码:

    FirefoxDriverSerialized serializedObject = new FirefoxDriverSerialized();
    Serializer serializer = new Serializer();
    serializedObject = serializer.DeSerializeObject(@"C:\firefoxDriver.qa");
    driver = serializedObject.DriverInstance;

    if (driver == null)
    {
        driver = new FirefoxDriver(firefoxProfile);
        serializedObject.DriverInstance = (FirefoxDriverSerialized)driver;
        serializer.SerializeObject(@"C:\firefoxDriver.qa", serializedObject);
    }

这是我构建的两个序列化器类:

public class Serializer
{
   public Serializer()
   {
   }

   public void SerializeObject(string filename, FirefoxDriverSerialized objectToSerialize)
   {
      Stream stream = File.Open(filename, FileMode.Create);
      BinaryFormatter bFormatter = new BinaryFormatter();
      bFormatter.Serialize(stream, objectToSerialize);
      stream.Close();
   }

   public FirefoxDriverSerialized DeSerializeObject(string filename)
   {
      FirefoxDriverSerialized objectToSerialize;
      Stream stream = File.Open(filename, FileMode.Open);
      BinaryFormatter bFormatter = new BinaryFormatter();
      objectToSerialize = (FirefoxDriverSerialized)bFormatter.Deserialize(stream);
      stream.Close();
      return objectToSerialize;
   }
}

[Serializable()]
public class FirefoxDriverSerialized : FirefoxDriver, ISerializable
{
    private FirefoxDriver driverInstance;
    public FirefoxDriver DriverInstance
    {
        get { return this.driverInstance; }
        set { this.driverInstance = value; }
    }

    public FirefoxDriverSerialized()
    {
    }

    public FirefoxDriverSerialized(SerializationInfo info, StreamingContext ctxt)
    {
        this.driverInstance = (FirefoxDriver)info.GetValue("DriverInstance", typeof(FirefoxDriver));
    }

    public void GetObjectData(SerializationInfo info, StreamingContext ctxt)
    {
        info.AddValue("DriverInstance", this.driverInstance);
    }
}

==================

2012 年 3 月 23 日更新 #2 - 修复了序列化/反序列化，但有另一个问题

这修复了调用代码。因为我们在调用 WebDriver.Quit() 时删除了 *.qa 文件，因为那是我们选择关闭浏览器的时候。这也会杀死我们缓存的驱动程序。因此，如果我们从一个新的浏览器窗口开始，我们将点击 catch block 并创建一个新实例并将其保存到我们的 *.qa 文件(以序列化形式)。

    FirefoxDriverSerialized serializedObject = new FirefoxDriverSerialized();
    Serializer serializer = new Serializer();

    try
    {
        serializedObject = serializer.DeSerializeObject(@"C:\firefoxDriver.qa");
        driver = serializedObject.DriverInstance;
    }
    catch
    {
        driver = new FirefoxDriver(firefoxProfile);
        serializedObject = new FirefoxDriverSerialized();
        serializedObject.DriverInstance = (FirefoxDriver)driver;
        serializer.SerializeObject(@"C:\firefoxDriver.qa", serializedObject);
    }

但是，仍然出现此异常:

Acu.QA.Main.Test_0055_GiftCertificate_UserCheckout:
SetUp : System.Runtime.Serialization.SerializationException : Type 'OpenQA.Selenium.Firefox.FirefoxDriver' in Assembly 'WebDriver, Version=2.16.0.0, Culture=neutral, PublicKeyToken=1c2bd1631853048f' is not marked as serializable.
TearDown : System.NullReferenceException : Object reference not set to an instance of an object.

此代码块中的第 3 行抛出异常:

   public void SerializeObject(string filename, FirefoxDriverSerialized objectToSerialize)
   {
      Stream stream = File.Open(filename, FileMode.Create);
      BinaryFormatter bFormatter = new BinaryFormatter();
      bFormatter.Serialize(stream, objectToSerialize);  // <=== this line 
      stream.Close();
   }

=====================

更新 #3 - 3/24/2012 - 通过不向构造函数传递任何内容来简化 FirefoxDriver 实例。稍后我将通过将 FirefoxProfile 传递给构造函数来使其更复杂。我仍然得到与更新 #2 相同的异常。

电话号码:

FirefoxDriverSerialized serializedObject = new FirefoxDriverSerialized();
Serializer serializer = new Serializer();
try
{
    serializedObject = serializer.DeSerializeObject(@"C:\firefoxDriver.qa");
    driver = serializedObject.DriverInstance;
}
catch
{
    //driver = new FirefoxDriver(firefoxProfile);
    driver = new FirefoxDriver();
    serializedObject.DriverInstance = (FirefoxDriver)driver;
    serializer.SerializeObject(@"C:\firefoxDriver.qa", serializedObject);
}

还必须在我的序列化对象类的构造函数中添加“:base()”:

[Serializable()]
public class FirefoxDriverSerialized : FirefoxDriver, ISerializable
{
    private FirefoxDriver driverInstance;
    public FirefoxDriver DriverInstance
    {
        get { return this.driverInstance; }
        set { this.driverInstance = value; }
    }

    public FirefoxDriverSerialized() : base()
    {
    }

    public FirefoxDriverSerialized(SerializationInfo info, StreamingContext ctxt)
    {
        this.driverInstance = (FirefoxDriver)info.GetValue("DriverInstance", typeof(FirefoxDriver));
    }

    public void GetObjectData(SerializationInfo info, StreamingContext ctxt)
    {
        info.AddValue("DriverInstance", this.driverInstance);
    }
}

==============

更新 #4 - 仅记录 OpenQA.Selenium.Firefox.FirefoxDriver 类的 stub 签名

using OpenQA.Selenium;
using OpenQA.Selenium.Remote;
using System;

namespace OpenQA.Selenium.Firefox
{
    public class FirefoxDriver : RemoteWebDriver, ITakesScreenshot
    {
        // CLASS DATA MEMBERS 

        //public static readonly bool AcceptUntrustedCertificates;
        //public static readonly string BinaryCapabilityName;
        //public static readonly bool DefaultEnableNativeEvents;
        //public static readonly int DefaultPort;
        //public static readonly string ProfileCapabilityName;

        // CONSTRUCTORS

        //public FirefoxDriver();
        //public FirefoxDriver(FirefoxProfile profile);
        //public FirefoxDriver(ICapabilities capabilities);
        //public FirefoxDriver(FirefoxBinary binary, FirefoxProfile profile);
        //public FirefoxDriver(FirefoxBinary binary, FirefoxProfile profile, TimeSpan commandTimeout);

        // PROPERTIES

        protected FirefoxBinary Binary { get; }
        protected FirefoxProfile Profile { get; }

        // METHODS

        //protected override RemoteWebElement CreateElement(string elementId);
        //public Screenshot GetScreenshot();
        //protected void PrepareEnvironment();
        //protected override void StartClient();
        //protected override void StopClient();
    }
}

Answer 1

创建您自己的源自 ISerializable 的自定义对象以及您要序列化和序列化该自定义对象的对象。如果第 3 方对象是 Sealed，则此特定示例将不起作用(还有其他方法仍然可以与 ISerializable 一起使用)。

根据请求更新

按问题更新

public class MyFirefoxDriver : FirefoxDriver, ISerializable
{
  public MyFirefoxDriver(<Interface/Class> firefoxProfile)
    :base(firefoxProfile)
  {
  }

  void GetObjectData(SerializationInfo info, StreamingContext context)
  {
    // Properties needing to be serialized
    info.AddValue("SomeProperty", base.SomeProperty);
  }
}

更新 2

你的新代码让我很困惑。我想你正在寻找..

serializedObject = serializer.DeSerializeObject(@"C:\firefoxDriver.qa");
driver = serializedObject;

这是因为 FirefoxDriverSerialized是 FireFoxDriver .

更新 3

需要注意的是，反序列化对象时不会调用构造函数。这意味着通常在构造函数中构造/设置的东西不会在反序列化时进行，这通常会导致 NullReferenceException .解决方法是实现 ISerializable并明确设置类工作所需的对象(GetObjectData 和特殊的反序列化器构造函数)。如果对所讨论对象的理解不简单，或者我们没有它的来源，这可能是最困难的。

It is important to stress that you need to implement both GetObjectData as well as the special constructor when ISerializable is added to a class. The compiler will warn you if GetObjectData is missing, but since it is impossible to enforce the implementation of a constructor, no warnings will be given if the constructor is absent and an exception will be thrown when an attempt is made to deserialize a class without the constructor.

public class MyObject
{
  public MyObject()
  {
    this.SomeOtherObject = new MyObject2();
  }
  public string Name { get; set; }
  public MyObject2 SomeOtherObject { get; set; }
}

public class MyObjectSerializable : MyObject, ISerializable
{
  protected MyObjectSerializable(SerializationInfo si, StreamingContext context) 
  {
    // base() is never called during deserialization
    // so use the special ISerializable constructor to set the value of the object
    // why not add it to the si.AddValue?
    // because, most likely in this question, it is not a [Serializable] object either
    // so we have to treat it differently as well
    this.SomeOtherObject = new MyObject2();
  }

  public override void GetObjectData(SerializationInfo si, StreamingContext context)
  {
    si.AddValue("Name", Name);
  }
}