Tag Archives: COM

在网上查了一下，应该是不能直接在WinForm中使用C#写的COM控件。
但可以用变通的方法测试COM控件中的方法，比如，下面的例子中，就可以测试addTest方法：

Type comType = null;
object comObject = null;

//这个无效，不知道为什么
//comType = Type.GetTypeFromProgID("XX.CSControl.TestControl");
if (comType == null)
{
    Guid guid = new Guid("4B4D1D4C-16CA-48E0-87A4-AFF3C6CB6E26");
    comType = Type.GetTypeFromCLSID(guid);
}

try
{
    comObject = Activator.CreateInstance(comType);
}
catch(Exception e)
{
    MessageBox.Show(e.Message);
    return;
}

object[] args = new object[2];
args[0] = 1;
args[1] = 2;

int ret = (int)comType.InvokeMember("addTest", BindingFlags.InvokeMethod, null, comObject, args);
if(ret==3)
{
    MessageBox.Show("TestOK");
}

这两天由于一个很挫的需求，准备开发一个COM组件，由于所有用户的客户端都安装有.Net Framework 4.0，加上工期紧的很，就准备用C#上了。

1、首先，建立一个Windows Forms Control Library项目

2、项目属性，Build，选中，Register for COM interop

3、项目属性，Signing，选中，Sign the assembly，并生成一个签名文件

4、编辑AssemblyInfo.cs，查看是否有下面两行，没有要添加

using System.Security;

[assembly: AllowPartiallyTrustedCallers()] 
[assembly: ComVisible(true)]

5、添加接口文件IObjectSafety.cs

using System;
using System.Runtime.InteropServices;

namespace CSControl
{
    //不要修改GUID
    [ComImport]
    [Guid("CB5BDC81-93C1-11CF-8F20-00805F2CD064")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    public interface IObjectSafety
    {
        [PreserveSig]
        int GetInterfaceSafetyOptions(ref Guid riid,
                      [MarshalAs(UnmanagedType.U4)] ref int pdwSupportedOptions,
                      [MarshalAs(UnmanagedType.U4)] ref int pdwEnabledOptions);

        [PreserveSig()]
        int SetInterfaceSafetyOptions(ref Guid riid,
                      [MarshalAs(UnmanagedType.U4)] int dwOptionSetMask,
                      [MarshalAs(UnmanagedType.U4)] int dwEnabledOptions);
    }
}

6、控件类要同时实现UserControl, IObjectSafety两个接口

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Reflection;
using System.IO;
using System.Diagnostics;
using System.Threading;
using System.Security;

namespace CSControl
{
    //更改为你自己的UUID
    [ComVisible(true)]
    [Guid("4B4D1D4C-16CA-48E0-87A4-AFF3C6CB6E26")]
    [ProgId("XX.CSControl.TestControl")]
    public partial class TestControl : UserControl, IObjectSafety
    {
        //===================================================
        //实现IObjectSafety接口
        //不要修改下面的GUID
        private const string _IID_IDispatch = "{00020400-0000-0000-C000-000000000046}";
        private const string _IID_IDispatchEx = "{a6ef9860-c720-11d0-9337-00a0c90dcaa9}";
        private const string _IID_IPersistStorage = "{0000010A-0000-0000-C000-000000000046}";
        private const string _IID_IPersistStream = "{00000109-0000-0000-C000-000000000046}";
        private const string _IID_IPersistPropertyBag = "{37D84F60-42CB-11CE-8135-00AA004BB851}";

        private const int INTERFACESAFE_FOR_UNTRUSTED_CALLER = 0x00000001;
        private const int INTERFACESAFE_FOR_UNTRUSTED_DATA = 0x00000002;
        private const int S_OK = 0;
        private const int E_FAIL = unchecked((int)0x80004005);
        private const int E_NOINTERFACE = unchecked((int)0x80004002);

        private bool _fSafeForScripting = true;
        private bool _fSafeForInitializing = true;

        public int GetInterfaceSafetyOptions(ref Guid riid,
                             ref int pdwSupportedOptions,
                             ref int pdwEnabledOptions)
        {
            int Rslt = E_FAIL;

            string strGUID = riid.ToString("B");
            pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER | INTERFACESAFE_FOR_UNTRUSTED_DATA;
            switch (strGUID)
            {
                case _IID_IDispatch:
                case _IID_IDispatchEx:
                    Rslt = S_OK;
                    pdwEnabledOptions = 0;
                    if (_fSafeForScripting == true)
                        pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER;
                    break;
                case _IID_IPersistStorage:
                case _IID_IPersistStream:
                case _IID_IPersistPropertyBag:
                    Rslt = S_OK;
                    pdwEnabledOptions = 0;
                    if (_fSafeForInitializing == true)
                        pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA;
                    break;
                default:
                    Rslt = E_NOINTERFACE;
                    break;
            }

            return Rslt;
        }

        public int SetInterfaceSafetyOptions(ref Guid riid,
                             int dwOptionSetMask,
                             int dwEnabledOptions)
        {
            int Rslt = E_FAIL;

            string strGUID = riid.ToString("B");
            switch (strGUID)
            {
                case _IID_IDispatch:
                case _IID_IDispatchEx:
                    if (((dwEnabledOptions & dwOptionSetMask) == INTERFACESAFE_FOR_UNTRUSTED_CALLER) &&
                         (_fSafeForScripting == true))
                        Rslt = S_OK;
                    break;
                case _IID_IPersistStorage:
                case _IID_IPersistStream:
                case _IID_IPersistPropertyBag:
                    if (((dwEnabledOptions & dwOptionSetMask) == INTERFACESAFE_FOR_UNTRUSTED_DATA) &&
                         (_fSafeForInitializing == true))
                        Rslt = S_OK;
                    break;
                default:
                    Rslt = E_NOINTERFACE;
                    break;
            }

            return Rslt;
        }

        //===================================================
        //实现UserControl接口
        ......
    }
}

7、编译，控件会自动注册

8、写个网页，测试一下

<!--CSControl-->
<object id="testControl" width="500" height="500" classid ="clsid:4B4D1D4C-16CA-48E0-87A4-AFF3C6CB6E26"&#93;</object>

9、打CAB包，发布到网站
由于是自己生产的签名文件，所以会有安全提示。最简单的方法是从靠谱的CA那里买一个证书，还有办法就是将证书导入到IE的信任列表中，再就是将IE的安全级别降为最低。

10、当然也可以通过命令行本地注册

rem 注册
regtlibv12 %PATH_TO_DLL_AND_TLB_FOLDER%\CSControl.tlb

rem 反注册
regtlibv12 -u %PATH_TO_DLL_AND_TLB_FOLDER%\CSControl.tlb

本篇文章介绍了如何用C#写一个简单的COM组件(Dll)。

1、新建一个C# Class Library项目“CSCOMTest”

2、项目中，新增一个接口文件IJustATestCOM.cs，Guid要自己生成

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;

namespace CSCOMTest
{
    [ComVisible(true)]
    [InterfaceType(ComInterfaceType.InterfaceIsDual)]
    [Guid("A5377871-3334-4679-A3CD-84312B1DCD3E")]
    public interface IJustATestCOM
    {
        int Add(int a, int b);
        String SayHiTo(String someOne);
    }
}

3、项目中，新增一个类文件JustATestCOM.cs，Guid要自己生成

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;

namespace CSCOMTest
{
    [ComVisible(true)]
    [Guid("A6E4F456-32C1-4C8E-9171-D616B5DA1E20")]
    [ProgId("CSCOMTest.JustATestCOM")]
    public class JustATestCOM : IJustATestCOM
    {
        public int Add(int a, int b)
        {
            return a + b;
        }

        public String SayHiTo(String someOne)
        {
            return "Hi " + someOne + "!";
        }
    }
}

4、项目属性->Application->Assembly Infomation->Make Assembly COM-Visible->打勾

5、项目属性->Signing->Sign the assembly->打勾
项目属性->Signing->Choose a strong name key file->New

6、编译

7、注册

#这里一定要用正确版本的gacutil及RegAsm
C:\VBS\DNFW4\gacutil.exe /i CSCOMTest.dll
C:\VBS\DNFW4\RegAsm.exe CSCOMTest.dll

8、反注册

#这里一定要用正确版本的gacutil及RegAsm
C:\VBS\DNFW4\gacutil.exe /u CSCOMTest
C:\VBS\DNFW4\RegAsm.exe /u CSCOMTest.dll

9、调用测试

'发生错误时，继续运行
On Error Resume Next

'清除错误状态
Err.Clear

Set Obj=CreateObject("CSCOMTest.JustATestCOM")

'输出错误信息
If Err.Number <> 0 Then
    WScript.Echo "Error: " & Err.Number
    WScript.Echo "Error (Hex): " & Hex(Err.Number)
    WScript.Echo "Source: " &  Err.Source
    WScript.Echo "Description: " &  Err.Description
    'Err.Clear
    '退出程序
    WScript.Quit(Err.Number)
End If

'On Error Goto 0

WScript.Echo obj.Add(1,2)
WScript.Echo obj.SayHiTo("dcom")


set obj=Nothing

10、生成tlb文件

regasm CSCOMTest.dll /tlb:CSCOMTest.tlb