c#中开发ActiveX的学习笔记【转】

1.为什么要用ActiveX?

网页本身的功能是有限的，要想实现一些网页本身不支持的功能，比如：网页上的p2p视频播放，就得靠ActiveX这种古老的技术。

2.c#能开发ActiveX吗？

严格意义上讲，c#是不能生成纯正ocx控件的，我们在vs.net中新建项目时，也找不到专门的"ActiveX项目"新建项，最多也只就能新 建"类库"得到一个dll而非ocx(因此我们也无法用传统的regsvr32来注册该dll)，但是c#能开发com组件，activeX控件本质上讲 跟com是一类技术，所以用c#开发"能够让网页调用的com类库"还是可行的。

3.开发步骤：

(1)新建一个类库
(2)修改项目的"属性"，在“生成”选项中把“输出”中的“为com互操作注册”勾中，然后再到“应用程序”选项中找到“程序集信息”按钮，点击它，在弹出的界面中勾中“使程序集COM可见(M)”

(3)修改AssemblyInfo.cs，增加[assembly: AllowPartiallyTrustedCallers()]，完整内容类似下面这样:

 1 using System.Reflection;
 2 using System.Runtime.CompilerServices;
 3 using System.Runtime.InteropServices;
 4 using System.Security;
 5 
 6 // General Information about an assembly is controlled through the following 
 7 // set of attributes. Change these attribute values to modify the information
 8 // associated with an assembly.
 9 [assembly: AssemblyTitle("ActiveXDemo")]
10 [assembly: AssemblyDescription("")]
11 [assembly: AssemblyConfiguration("")]
12 [assembly: AssemblyCompany("Microsoft")]
13 [assembly: AssemblyProduct("ActiveXDemo")]
14 [assembly: AssemblyCopyright("Copyright ? Microsoft 2009")]
15 [assembly: AssemblyTrademark("")]
16 [assembly: AssemblyCulture("")]
17 [assembly: AllowPartiallyTrustedCallers()]
18 
19 // Setting ComVisible to false makes the types in this assembly not visible 
20 // to COM components.  If you need to access a type in this assembly from 
21 // COM, set the ComVisible attribute to true on that type.
22 [assembly: ComVisible(true)]
23 
24 // The following GUID is for the ID of the typelib if this project is exposed to COM
25 [assembly: Guid("bd585d12-7f22-4b3f-959f-18efbfc53f94")]
26 
27 // Version information for an assembly consists of the following four values:
28 //
29 //      Major Version
30 //      Minor Version 
31 //      Build Number
32 //      Revision
33 //
34 // You can specify all the values or you can default the Build and Revision Numbers 
35 // by using the ‘*‘ as shown below:
36 // [assembly: AssemblyVersion("1.0.*")]
37 [assembly: AssemblyVersion("1.0.0.0")]
38 [assembly: AssemblyFileVersion("1.0.0.0")]

(4)新建一个IObjectSafety接口文件IObjectSafety.cs，内容如下:

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 using System.Runtime.InteropServices;
 5 
 6 namespace ActiveXDemo
 7 {
 8     [ComImport, GuidAttribute("CB5BDC81-93C1-11CF-8F20-00805F2CD064")]
 9     [InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
10     public interface IObjectSafety
11     {
12         [PreserveSig]
13         int GetInterfaceSafetyOptions(ref Guid riid, [MarshalAs(UnmanagedType.U4)] ref int pdwSupportedOptions, [MarshalAs(UnmanagedType.U4)] ref int pdwEnabledOptions);
14 
15         [PreserveSig()]
16         int SetInterfaceSafetyOptions(ref Guid riid, [MarshalAs(UnmanagedType.U4)] int dwOptionSetMask, [MarshalAs(UnmanagedType.U4)] int dwEnabledOptions);
17     }
18 
19 }

该内容除命名空间可以更改外，其它内容都是固定的，不要修改
(5)新建一个：Windows Forms-->“用户控件”,我们的主要逻辑就写在这里(还可以在它上面随便放置其它windows常用控件，跟winForm开发一样)，不过首先要修改类定义，让其实现我们刚才定义的接口

  1 using System;
  2 using System.Runtime.InteropServices;
  3 using System.Threading;
  4 using System.Windows.Forms;
  5 
  6 
  7 namespace ActiveXDemo
  8 {
  9     [Guid("8d7d8518-ca58-4863-b94d-3c616fda7b35")]
 10     public partial class MyActiveX : UserControl,IObjectSafety
 11     {
 12         delegate void D(object obj);
 13 
 14         public MyActiveX()
 15         {
 16             InitializeComponent();
 17         }
 18 
 19         #region IObjectSafety 成员
 20 
 21         private const string _IID_IDispatch = "{00020400-0000-0000-C000-000000000046}";
 22         private const string _IID_IDispatchEx = "{a6ef9860-c720-11d0-9337-00a0c90dcaa9}";
 23         private const string _IID_IPersistStorage = "{0000010A-0000-0000-C000-000000000046}";
 24         private const string _IID_IPersistStream = "{00000109-0000-0000-C000-000000000046}";
 25         private const string _IID_IPersistPropertyBag = "{37D84F60-42CB-11CE-8135-00AA004BB851}";
 26 
 27         private const int INTERFACESAFE_FOR_UNTRUSTED_CALLER = 0x00000001;
 28         private const int INTERFACESAFE_FOR_UNTRUSTED_DATA = 0x00000002;
 29         private const int S_OK = 0;
 30         private const int E_FAIL = unchecked((int)0x80004005);
 31         private const int E_NOINTERFACE = unchecked((int)0x80004002); 32  33         private bool _fSafeForScripting = true; 34         private bool _fSafeForInitializing = true; 35  36         public int GetInterfaceSafetyOptions(ref Guid riid, ref int pdwSupportedOptions, ref int pdwEnabledOptions) 37         { 38             int Rslt = E_FAIL; 39  40             string strGUID = riid.ToString("B"); 41             pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER | INTERFACESAFE_FOR_UNTRUSTED_DATA; 42             switch (strGUID) 43             { 44                 case _IID_IDispatch: 45                 case _IID_IDispatchEx: 46                     Rslt = S_OK; 47                     pdwEnabledOptions = 0; 48                     if (_fSafeForScripting == true) 49                         pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER; 50                     break; 51                 case _IID_IPersistStorage: 52                 case _IID_IPersistStream: 53                 case _IID_IPersistPropertyBag: 54                     Rslt = S_OK; 55                     pdwEnabledOptions = 0; 56                     if (_fSafeForInitializing == true) 57                         pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA; 58                     break; 59                 default: 60                     Rslt = E_NOINTERFACE; 61                     break; 62             } 63  64             return Rslt; 65         } 66  67         public int SetInterfaceSafetyOptions(ref Guid riid, int dwOptionSetMask, int dwEnabledOptions) 68         { 69             int Rslt = E_FAIL; 70             string strGUID = riid.ToString("B"); 71             switch (strGUID) 72             { 73                 case _IID_IDispatch: 74                 case _IID_IDispatchEx: 75                     if (((dwEnabledOptions & dwOptionSetMask) == INTERFACESAFE_FOR_UNTRUSTED_CALLER) && (_fSafeForScripting == true)) 76                         Rslt = S_OK; 77                     break; 78                 case _IID_IPersistStorage: 79                 case _IID_IPersistStream: 80                 case _IID_IPersistPropertyBag: 81                     if (((dwEnabledOptions & dwOptionSetMask) == INTERFACESAFE_FOR_UNTRUSTED_DATA) && (_fSafeForInitializing == true)) 82                         Rslt = S_OK; 83                     break; 84                 default: 85                     Rslt = E_NOINTERFACE; 86                     break; 87             } 88  89             return Rslt; 90         } 91  92         #endregion 93  94         private void MyActiveX_Load(object sender, EventArgs e) 95         { 96              97         } 98  99 100         public void Start(object obj) 101         {102             for (int i = 0; i < 10; i++)103             {104                 Thread t = new Thread(new ParameterizedThreadStart(ShowTime));105                 t.Start(obj.ToString() + "，线程：" + i.ToString());                106             }        107         }108 109         private void button1_Click(object sender, EventArgs e)110         {111             Start("Hello World");112         }113 114         void ShowTime(object obj)115         {116             if (this.listBox1.InvokeRequired)117             {118                 D d = new D(DelegateShowTime);119                 listBox1.Invoke(d, obj);120             }121             else122             {123                 this.listBox1.Items.Add(obj);124             }125 126             127         }128 129 130         void DelegateShowTime(object obj)131         {132             this.listBox1.Items.Add(obj);133         }134 135 136     }137 }

#region IObjectSafety 成员 ... #endregion这一段的内容是固定的，不要修改，其它内容根据自己的业务要求自行修改，另外类前面要加上Guid的标识，以便网页调用时，能用CLSID="xxx"来调用

基本上这样弄完后，就可以在网页中，用类似下面这样的代码来本机调用了：

注意：c#定义的public方法，如果想直接让js调用，只能返回string,DateTime,int,double这一类基本值类型，其它返回类型比如array,object，在js中要么直接报错，要么得到null

1 <object id="x" classid="clsid:8d7d8518-ca58-4863-b94d-3c616fda7b35"></object>
2 <hr />
3 <input type="button" value="调用ActiveX中的多线程方法" onclick="fnTest()" />
4 <script type="text/javascript">
5 var fnTest = function(){
6     var x = document.getElementById("x");
7     x.Start("这是js中的参数");
8 }
9 </script>

4.安装部署

前面已经提到了,c#开发的（伪）"ActiveX"控件并非纯正的ocx，所以只能用RegAsm.Exe xxx.dll来进行程序集的注册，这里要注意一点：在开发机上，项目编译后vs.net会自动将bin\debug\xxx.dll调用regasm注 册，但在别人机器上就不行了，为了能在调试时模拟其它机器的运行结果，可以在编译后，手动用类似 regAsm.exe D:\MyDoc\ActiveXDemo\output\ActiveXDemo.dll /u 来反注册(在vs.net命令行模式下)

 

然后在安装项目上，右键"添加"-->"项目输出"-->"主输出"-->在项目下拉框中选择activex所对应的项目即可.

注意:"主输出来自xxx"的属性栏中，有一个"Register"必须选择"vsdrpCOM"

另外还有一个问题，可能是我机器的个别现象，每次activex项目有修改时，建议最好手动清除安装项目debug目录下的文件，再重新生成安装项目，否则有时候会发现activex修改了，但是安装包中包含的dll还是未修改过的版本。
 

后话：c#开发的东西是运行于.net 框架之上的，就好比java开发的东西必须要java runtime才能运行一样，利用本文方法开发出来的dll也必须要安装.net框架才能跑起来，幸好最新的win7中已经集成了.net框架，当然您如 果对于庞大的.net框架安装程序很敏感，仍然觉得纯正的ocx更好的话，建议还是用vb/delphi/c++这一类老牌的开发工具/语言实现。(可以 参考我的另一篇重温delphi之:如何快速开发原生ActiveX控件)

 

示例源代码下载:http://files.cnblogs.com/yjmyzz/ActiveXDemo.rar