如何序列化一个IntPtr(在c#中)指向一个来自c ++ dll的对象 [英] How to serialize a IntPtr (in c#) pointing to a object that comes from a c++ dll

问题描述

我在C#Windows Forms应用程序中使用了一个C ++ dll.

I''ve got a c++ dll that i use in my c# windows forms app.

[DllImport("dllname.dll", EntryPoint = "?dllMethod@@YA_NPBDAAPAEAAH@Z", CallingConvention = CallingConvention.Cdecl)]
private static extern bool dllMethod([MarshalAs(UnmanagedType.LPStr)]string fname, out IntPtr descriptor, out int length);

在我的C#应用​​程序中，我只想使用该Dll返回的IntPtr数据序列化哈希表...所以我正在这样做:

In my c# app, i just want to serialize a hashtable with the IntPtr data that''s returned by that Dll... So i''m doing this:

[Serializable]
public class TopSurfDescriptor
{
  public IntPtr descriptor;
  public int length;
}
[Serializable]
public class Descriptors
{        
   private Hashtable descriptors=null;

   public void AddDescriptor(string key,TopSurfDescriptor descriptor)
   {
            descriptors.Add(key, descriptor);
   }
   public Descriptors()
   { 
      if (File.Exists(@"Descriptors.dat"))
      {
           FileStream fs = new FileStream(@"Descriptors.dat", FileMode.Open);
           try
           {
               BinaryFormatter formatter = new BinaryFormatter();
               descriptors = (Hashtable)formatter.Deserialize(fs);
           }
           catch (SerializationException){ throw; }

           finally {fs.Close(); }
       }
       else
           descriptors = new Hashtable();
   }

//AND
   public void Save()
   {
       FileStream fs = new FileStream(@"Descriptors.dat", FileMode.Create);

       BinaryFormatter formatter = new BinaryFormatter();
       try
       {
           formatter.Serialize(fs, descriptors);
       }
       catch (SerializationException e){ throw; }
       finally { fs.Close(); }
   }

如果我不关闭应用程序，则序列化和反序列化工作正常，但是如果我关闭它并以调试模式再次运行(从Visual Studio中)，则可以看到反序列化的过程运行良好((我看到hastable包含了所有数据，并且指向正确的TopSurfDescriptor类型的IntPtr，但是如果我将此指针从DLL传递到其他方法，则会出现异常，即内存可能已损坏或无法访问...

当我分析序列化的文件(在磁盘上)时，似乎数据不存在(因为文件很小)，而只有IntPtr.因此，我认为问题是这样的事实，即从外部dll返回的对象(内存)不是可序列化的.

if i dont close the app the serialization and deserialization works fine, but if i close it and run it again (from visual studio) in debug mode i can see the process of deserialization working good, (i see the hastable with all the data and the IntPtr pointing to the correct TopSurfDescriptor type, but if i pass this pointer to other method from the DLL i got the exception that the memory can be corrupt or dont have access...

when I analyze the serialized file (on disk) i seems that the data is not there (because the file is to small), but only the IntPtr. So, i think the problem is the fact that the object (memory) that is returned from the external dll is not beeing serializable.

推荐答案

您的TopSurfDescriptor类是序列化IntPtr就是它所拥有的.
如果您希望以这种方式保存/加载数据，则需要在内存地址处检索数据并进行客户序列化/反序列化.

Your TopSurfDescriptor class is serializing the IntPtr as that is what it holds.
You would need to retrieve the data at the memory address and do customer serialization/deserialization if you wish to save/load it this way.

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