c#中开发ActiveX的学习笔记
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:
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:
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
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 else
122 {
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
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)
当然,如果您不勾选3.(2)中所说的“为com互操作注 册”,vs编译时便不会自动注册,但是这样调试起来不太方便,另外注册/反注册时的RegAsm.exe要起开发环境中的版本一致(比如你开发时设置是 64位版本,那么反注册也要用64位版本的RegAsm.exe)
另外,我们也不可能在每个客户机上手动用RegAsm.exe来帮客户注册,所以我们还得新建安装项目来做一个安装包,这个比较简单,直接新建一个"其他项目类型-->安装和部署-->安装项目"即可
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)