C#编写ActiveX网页截图控件

2019-12-30 13:05:15刘景俊

新建用户控件,并派生IObjectSafe接口,接口实现是固定内容 


 [Guid("61D7F413-A1B2-48A9-B851-5BFBCF50280C")] //使用VS工具里的GUID生成器生成唯一码
 public partial class PSLib : UserControl, IObjectSafety
 {
 #region IObjectSafety 成员
 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;
 }
 #endregion 

IE调用ActiveX控件: 


<!DOCTYPE html>
<html>
 <head>
 <title>测试</title>
 
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 <meta http-equiv="description" content="this is my page">
 <meta http-equiv="content-type" content="text/html; charset=UTF-8">
 <script>
 function jt(){
  var str="";
  try
  {
  var obj = document.getElementById("MyActiveX"); 
   str=obj.PrintScreen();
  }
  catch(e)
  {
  alert(e);
  return;
  }

  var img=document.getElementById("img");
  img.src="data:image/jpeg;base64,"+str;//接受base64编码后的图片
 }
 </script>
 </head>
 
 <body>
 <OBJECT ID="MyActiveX" WIDTH="120" HEIGHT=20" CLASSID="CLSID:61D7F413-A1B2-48A9-B851-5BFBCF50280C"></OBJECT>
 <input type="button" value="截图" onclick="jt();">
 <Image id ="img" />
 </body>
</html>