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[英]System.InvalidCastException trying to build a COM client and a COM server in C#
[英]InvalidCastException with COM client and server in C#
我知道有关此主题的问题很多,但我相信我在过去10天内都经历了所有这些问题,但我找不到我所遭受的严重错误的解决方案。
我在C#中有一个COM服务器dll,在C#中有一个COM客户端。 Windows 7中的全部。我收到InvalidCastException,但无法解决问题。 我开始怀疑是否可以在C#中创建COM服务器。
我在实例化COM对象时遇到了该异常:
Test.MyImplementation mi = new Test.MyImplementation();
未处理System.InvalidCastException HResult = -2147467262消息=无法将类型为“ MyTest.MyImplementation”的对象强制转换为类型“ Test.MyImplementation”。 Source = ConsoleApplication3 StackTrace:位于c:\\ Users \\ rkohn \\ Documents \\ Visual Studio 2013 \\ Projects \\ ConsoleApplication3 \\ ConsoleApplication3 \\ Program.cs:ConsoleAppCOM.Program.Main(String [] args),位于System.AppDomain._nExecuteAssembly( RuntimeAssembly程序集,位于Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly(),位于System.Threading.ExecutionContext.RunInternal(ExecutionContext执行上下文,ContextCallback回调,对象状态,布尔状态,位于System.Threading.ExecutionContext.Run()处。在System.Threading.ExecutionContext.Run处的ExecutionContext executeContext,ContextCallback回调,对象状态,布尔值保持SyncCtx)在System.Threading.ThreadHelper.ThreadStart()处的ExecutionContext executeContext,ContextCallback回调,对象状态)InnerException:
这是COM服务器代码:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
namespace MyTest
{
[ComVisible(true)]
[Guid("DBE0E8C4-DABA-41F3-B6A4-CAFE353D3D16")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IPimcManager
{
void GetTabletCount(out UInt32 count);
}
[ComVisible(true)]
[Guid("C6659361-DABA-4746-931C-CAFE4B146690")]
[ProgId("FakeServer.MyImplementation")]
[ClassInterface(ClassInterfaceType.None)]
[ComDefaultInterface(typeof(IPimcManager))] //This to explicitly establish which is the default interface
public class MyImplementation : IPimcManager
{
public MyImplementation() { }
~MyImplementation() { }
public void GetTabletCount(out UInt32 count)
{
Console.WriteLine("GetTabletCount called!");
count = 1;
}
}
}
这是客户端代码:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
namespace Test
{
[ComImport]
[Guid(PimcConstants.IPimcManagerIID)]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IPimcManager
{
void GetTabletCount(out UInt32 count);
}
[ComImport]
[Guid(PimcConstants.PimcManagerCLSID)]
class MyImplementation
{
}
// void GetTabletCount(out UInt32 count);
//void GetTablet(UInt32 tablet, out IPimcTablet IPimcTablet);
internal static class PimcConstants
{
//internal const string PimcManagerCLSID = "e23b1ced-5e47-4fdb-af66-b20370261b5e";
internal const string PimcManagerCLSID = "C6659361-DABA-4746-931C-CAFE4B146690";
internal const string IPimcManagerIID = "DBE0E8C4-DABA-41F3-B6A4-CAFE353D3D16";
//internal const string PimcManagerCLSID = "c6659361-daba-4746-931c-cafe4b146690";
//internal const string IPimcManagerIID = "dbe0e8c4-daba-41f3-b6a4-cafe353d3d16";
//internal const string IPimcManagerIID = "af44bf80-36dd-4118-b4cf-8b1e3f4fb9ce";
}
}
namespace ConsoleAppCOM
{
class Program
{
[STAThread]
static void Main(string[] args)
{
Test.MyImplementation mi = new Test.MyImplementation();
Test.IPimcManager pimcManager = ((Test.IPimcManager)mi);
uint cTablets = 0;
pimcManager.GetTabletCount(out cTablets);
System.Console.WriteLine(DateTime.Now + "-VALUE OBTAINED from PimcManager.GetTabletCount: " + cTablets);
//Thread.Sleep(5);
System.Console.ReadLine();
}
}
}
我已经尝试过STAThread,在服务器项目属性中选中了“为COM Interop注册”,并检查了客户端和服务器都针对x64 ...
我已经用C ++创建了一个COM Server,并且同一客户端可以与C ++ COM Server完美配合。 没有InvalidCastException。
这是从C#FakeServer的类型库获得的IDL:
// Generated .IDL file (by the OLE/COM Object Viewer)
//
// typelib filename: FakeServer.tlb
[
uuid(A3CFF4E2-8724-461F-AFD4-D74583E89513),
version(1.0),
custom(90883F05-3D28-11D2-8F17-00A0C9A6186D, "FakeServer, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null")
]
library FakeServer
{
// TLib : // TLib : mscorlib.dll : {BED7F4EA-1A96-11D2-8F08-00A0C9A6186D}
importlib("mscorlib.tlb");
// TLib : OLE Automation : {00020430-0000-0000-C000-000000000046}
importlib("stdole2.tlb");
// Forward declare all types defined in this typelib
interface IPimcManager;
[
odl,
uuid(DBE0E8C4-DABA-41F3-B6A4-CAFE353D3D16),
version(1.0),
oleautomation,
custom(0F21F359-AB84-41E8-9A78-36D110E6D2F9, "MyTest.IPimcManager")
]
interface IPimcManager : IUnknown {
HRESULT _stdcall GetTabletCount([out] unsigned long* count);
};
[
uuid(C6659361-DABA-4746-931C-CAFE4B146690),
version(1.0),
custom(0F21F359-AB84-41E8-9A78-36D110E6D2F9, "MyTest.MyImplementation")
]
coclass MyImplementation {
interface _Object;
[default] interface IPimcManager;
};
};
这是从C ++ COM Server的类型库中获得的IDL(请不要考虑添加到接口中的Name方法,我在测试中就这样做了):
// Generated .IDL file (by the OLE/COM Object Viewer)
//
// typelib filename: simplecomserver.tlb
[
uuid(6F818C55-E6AD-488B-9EB6-511C0CCC0612),
version(1.0),
custom(DE77BA64-517C-11D1-A2DA-0000F8773CE9, 134218331),
custom(DE77BA63-517C-11D1-A2DA-0000F8773CE9, 1413900762),
custom(DE77BA65-517C-11D1-A2DA-0000F8773CE9, "Created by MIDL version 8.00.0603 at Tue Oct 21 11:12:41 2014
")
]
library LibCOMServer
{
// TLib : // TLib : OLE Automation : {00020430-0000-0000-C000-000000000046}
importlib("stdole2.tlb");
// Forward declare all types defined in this typelib
interface ICOMServer;
[
odl,
uuid(7F24AABF-C822-4C18-9432-21433208F4DC),
oleautomation
]
interface ICOMServer : IUnknown {
HRESULT _stdcall Name([out, retval] BSTR* objectname);
HRESULT _stdcall GetTabletCount([out] unsigned long* pcTablets);
};
[
uuid(6AE24C34-1466-482E-9407-90B98798A712),
helpstring("COMServer object")
]
coclass CoCOMServer {
[default] interface ICOMServer;
};
};
与从接口_Object继承的C#协类是否有任何关系?
coclass MyImplementation {
interface _Object;
[default] interface IPimcManager;
};
任何帮助表示赞赏。
也许您的MyImplementation
需要实现IPimcManager
(就像在服务器代码中一样)。 尝试:
class MyImplementation : IPimcManager
{
public void GetTabletCount(out UInt32 count)
{
// implement your code here
}
}
希望这可以帮助。
请尝试以下操作:
在您的客户端类声明上,而不是
[ComImport]
[Guid(PimcConstants.PimcManagerCLSID)]
class MyImplementation
{
}
将其更改为接口并使用父接口GUID:
[ComImport]
[Guid(PimcConstants.IPimcManagerIID)]
interface MyImplementation:IPimcManager
{
}
希望能帮助到你
在.NET客户端中声明共同创建(可实例化)的COM类的通常模式不仅要求您声明类(例如下面的FooClass
),而且还需要类接口( Foo
),这是您将与new
一起使用的接口( new Foo()
)。 例如:
[ComImport]
[Guid(IIDs.IFoo)] // IIDs.IFoo is a string constant containing the interface's IID
[CoClass(typeof(FooClass))]
public interface Foo : IFoo { }
[ComImport]
[Guid(CLSIDs.Foo)] // CLSIDs.Foo is a string constant containing the co-class' CLSID
[ComDefaultInterface(typeof(IFoo))]
public class FooClass { }
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