Question

使用this作为参考，我正在尝试创建一个异步可插拔协议，该协议仅暂时可用于我的应用程序（而不是在系统范围内注册）。我正在使用CoInternetGetSession然后调用RegisterNameSpace来执行此操作。但是，当我拨打RegisterNameSpace时，我收到了一个AccessViolation异常：Attempting to read or write protected memory。

知道发生了什么事吗？

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);

    }

PluggableProtocolFactory中的CreateInstance方法永远不会被调用。（一个断点永远不会被击中）所以在RegisterNameSpace方法中发生了其他事情。

我尝试以管理员和普通用户身份运行。两种情况都有相同的错误。

Answer 1

您在RegisterNameSpace方法中调用PluggableProtocolFactory的构造函数，但不调用CreateInstance方法。我认为这就是你的问题所在，从来没有创建过传递给你的方法的IInternetProtocol实例。

Answer 2

好的，想通了：IInternetSession接口的声明是错误的：

这是我从monoblog获得的更好的一个：

[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();
}

异步可插拔协议

2 个答案: