异步可插拔协议

Asynchronous Pluggable Protocols(异步可插拔协议)

问题描述

使用 this 作为参考，我正在尝试创建一个异步可插入协议，仅对我的应用程序暂时可用(并且未在系统范围内注册).我正在使用 CoInternetGetSession 然后调用 RegisterNameSpace 来完成它.但是，当我调用 RegisterNameSpace 时，我得到一个 AccessViolation 异常:Attempting to read or write protected memory.

Using this as reference, I'm trying to create an asynchronous pluggable protocol that is only temporarily available to my app (and not registered systemwide). I'm using CoInternetGetSession and then calling RegisterNameSpace to do it. However, when I make the call to RegisterNameSpace I get an AccessViolation exception: Attempting to read or write protected memory.

知道发生了什么吗?

我的代码如下所示:

[ComImport]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[Guid("00000001-0000-0000-C000-000000000046")]
[ComVisible(true)]
public interface IClassFactory
{
    void CreateInstance(IntPtr pUnkOuter, ref Guid riid, out IntPtr ppvObject);
    void LockServer(bool fLock);
}

/* Custom class to act as a class factory that create's an instance of the protocol */
[Guid("0b9c4422-2b6e-4c2d-91b0-9016053ab1b1")]
[ComVisible(true),ClassInterface(ClassInterfaceType.AutoDispatch)]
public class PluggableProtocolFactory : IClassFactory
{
    public Type AppType;
    public PluggableProtocolFactory(Type t)
    {
        this.AppType = t;
    }
    public void CreateInstance(IntPtr pUnkOuter, ref Guid riid, out IntPtr ppvObject)
    {
        riid = ProtocolSupport.GetGuid(this.AppType);
        IInternetProtocol p = Activator.CreateInstance(this.AppType) as IInternetProtocol;
        ppvObject = Marshal.GetComInterfaceForObject(p, typeof(IInternetProtocol));
    }

    public void LockServer(bool fLock)
    {
        var b = fLock;
    }

}

[ComVisible(true)]
[ComImport]
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
[Guid("79eac9e7-baf9-11ce-8c82-00aa004ba90b")]
public interface IInternetSession
{
    void CreateBinding(); // Not Implemented
    void GetCache(); // Not Implemented
    void GetSessionOption(); // Not Implemented
    void RegisterMimeFilter([MarshalAs(UnmanagedType.Interface)] IClassFactory pCF, ref Guid rclsid, [MarshalAs(UnmanagedType.LPWStr)] string pwzType);
    void RegisterNameSpace([MarshalAs(UnmanagedType.Interface)] IClassFactory pCF, ref Guid rclsid, [MarshalAs(UnmanagedType.LPWStr)] string pwzProtocol,
                           UInt32 cPatterns, [MarshalAs(UnmanagedType.LPArray,ArraySubType=UnmanagedType.LPWStr)] string[] ppwzPatterns, UInt32 dwReserved);
    void SetCache(); // Not Implemented
    void SetSessionOption(); // Not Implemented
    void UnregisterMimeFilter(IClassFactory pCF, [MarshalAs(UnmanagedType.LPWStr)] string pwzType);
    void UnregisterNameSpace(IClassFactory pCF, [MarshalAs(UnmanagedType.LPWStr)] string pwzProtocol);
}

[ComVisible(false)] public interface IComRegister
{
    void Register(Type t);
    void Unregister(Type t);
}

[ComVisible(false), AttributeUsage(AttributeTargets.Class, AllowMultiple=true) ] 
public class AsyncProtocolAttribute : Attribute, IComRegister
{
    public string Name;
    public string Description;

    [DllImport("urlmon.dll",PreserveSig=false)]
    public static extern int CoInternetGetSession(UInt32 dwSessionMode /* = 0 */, ref IInternetSession ppIInternetSession, UInt32 dwReserved /* = 0 */);

    public void Register(Type t)
    {
        IInternetSession session = null;
        CoInternetGetSession(0, ref session, 0);
        Guid g = new Guid("79EAC9E4-BAF9-11CE-8C82-00AA004BA90B");
        session.RegisterNameSpace(new PluggableProtocolFactory(t), ref g, this.Name, 0, null, 0);

    }

永远不会调用 PluggableProtocolFactory 中的 CreateInstance 方法.(那里的断点永远不会被击中)所以 RegisterNameSpace 方法内部发生了其他事情.

The CreateInstance method in PluggableProtocolFactory never gets called. (A break point there never gets hit) so something else is happening inside the RegisterNameSpace method.

我尝试以管理员和普通用户的身份运行.两种情况都出现同样的错误.

I tried running both as an administrator and a normal user. Same error in both occasions.

推荐答案

好的，搞清楚了:IInternetSession接口的声明错误:

OK, figured it out: The declaration of the IInternetSession interface was wrong:

这是我从 monoblog 中挑选的一个更好的::p>

Here's a better one I picked up from monoblog:

[ComVisible(true), Guid("79eac9e7-baf9-11ce-8c82-00aa004ba90b"),InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
public interface IInternetSession
{
    [PreserveSig]
    int RegisterNameSpace(
        [In] IClassFactory classFactory,
        [In] ref Guid rclsid,
        [In, MarshalAs(UnmanagedType.LPWStr)] string pwzProtocol,
        [In]
            int cPatterns,
        [In, MarshalAs(UnmanagedType.LPWStr)]
            string ppwzPatterns,
        [In] int dwReserved);

    [PreserveSig]
    int UnregisterNameSpace(
        [In] IClassFactory classFactory,
        [In, MarshalAs(UnmanagedType.LPWStr)] string pszProtocol);

    int Bogus1();

    int Bogus2();

    int Bogus3();

    int Bogus4();

    int Bogus5();
}

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