用C#编写ActiveX控件（二）
Homer
public void ShowMessage(string msg) 
{ 
if(msg != null) 
{ MessageBox.Show(msg); 
} 
} <body bgcolor='#223344'> <object id="helloworld" classid="clsid:9551B223-6188-4387-B293-C7D9D8173E3A" Width="184" Height="96" > </object> <br> <input type='button' onclick='helloworld.ShowMessage(“Hello World!”)' value='Click'> </body> 现在，重新访问http://localhost/helloworld.htm，单击Click按钮，应该可以实现交互了。
但是结果却很遗憾，我们发现IE跳出了对话框，如图所示：
[Guid("CB5BDC81-93C1-11CF-8F20-00805F2CD064"),InterfaceType(ComInterfaceType.InterfaceIsIUnknown)] public interface IObjectSafety { // methods void GetInterfacceSafyOptions( System.Int32 riid, out System.Int32 pdwSupportedOptions, out System.Int32 pdwEnabledOptions); void SetInterfaceSafetyOptions( System.Int32 riid, System.Int32 dwOptionsSetMask, System.Int32 dwEnabledOptions); } 注意，这个GUID是不能改的。然后，我们在Demo类里面实现这个接口。增加一下代码：
IObjectSafety 成员#region IObjectSafety 成员 public void GetInterfacceSafyOptions(Int32 riid, out Int32 pdwSupportedOptions, out Int32 pdwEnabledOptions) { // TODO: 添加 WebCamControl.GetInterfacceSafyOptions 实现 pdwSupportedOptions = 1; pdwEnabledOptions = 2; } public void SetInterfaceSafetyOptions(Int32 riid, Int32 dwOptionsSetMask, Int32 dwEnabledOptions) { // TODO: 添加 WebCamControl.SetInterfaceSafetyOptions 实现 } #endregion
