C#彻底解决Web Browser 跨域读取Iframes内容
用C# winform的控件web browser 读取网页内容，分析一下数据，做一些采集工作。
如果是同一个域名下面还是好办的，基本上用HtmlAgilityPack就完全可以解决问题。
但是现在遇到跨域问题，比如我需要打开页面上存在的广告联盟的地址，进行保存。
这就是牵扯到跨域。
一般的错误是：拒绝访问。
"Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))"。
因为你没有在这个网站去修改另一个网站数据的权利。
怎么办？很困恼吧。现在就告诉大家一个好办法。
直接上代码了。
工具类，大家保存成一个类。需要引用mshtml
| using System; using System.Runtime.InteropServices; using System.Windows.Forms; using mshtml; namespace WebBrowserTest { // This is the COM IServiceProvider interface, not System.IServiceProvider .Net interface! [ComImport(), ComVisible(true), Guid("6D5140C1-7436-11CE-8034-00AA006009FA"), InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)] public interface IServiceProvider { [return: MarshalAs(UnmanagedType.I4)] [PreserveSig] int QueryService(ref Guid guidService, ref Guid riid, [MarshalAs(UnmanagedType.Interface)] out object ppvObject); } public enum OLECMDF { OLECMDF_DEFHIDEONCTXTMENU = 0x20, OLECMDF_ENABLED = 2, OLECMDF_INVISIBLE = 0x10, OLECMDF_LATCHED = 4, OLECMDF_NINCHED = 8, OLECMDF_SUPPORTED = 1 } public enum OLECMDID { OLECMDID_PAGESETUP = 8, OLECMDID_PRINT = 6, OLECMDID_PRINTPREVIEW = 7, OLECMDID_PROPERTIES = 10, OLECMDID_SAVEAS = 4 } public enum OLECMDEXECOPT { OLECMDEXECOPT_DODEFAULT, OLECMDEXECOPT_PROMPTUSER, OLECMDEXECOPT_DONTPROMPTUSER, OLECMDEXECOPT_SHOWHELP } [ComImport, Guid("D30C1661-CDAF-11d0-8A3E-00C04FC9E26E"), TypeLibType(TypeLibTypeFlags.FOleAutomation | TypeLibTypeFlags.FDual | TypeLibTypeFlags.FHidden)] public interface IWebBrowser2 { [DispId(100)] void GoBack(); [DispId(0x65)] void GoForward(); [DispId(0x66)] void GoHome(); [DispId(0x67)] void GoSearch(); [DispId(0x68)] void Navigate([In] string Url, [In] ref object flags, [In] ref object targetFrameName, [In] ref object postData, [In] ref object headers); [DispId(-550)] void Refresh(); [DispId(0x69)] void Refresh2([In] ref object level); [DispId(0x6a)] void Stop(); [DispId(200)] object Application { [return: MarshalAs(UnmanagedType.IDispatch)] get; } [DispId(0xc9)] object Parent { [return: MarshalAs(UnmanagedType.IDispatch)] get; } [DispId(0xca)] object Container { [return: MarshalAs(UnmanagedType.IDispatch)] get; } [DispId(0xcb)] object Document { [return: MarshalAs(UnmanagedType.IDispatch)] get; } [DispId(0xcc)] bool TopLevelContainer { get; } [DispId(0xcd)] string Type { get; } [DispId(0xce)] int Left { get; set; } [DispId(0xcf)] int Top { get; set; } [DispId(0xd0)] int Width { get; set; } [DispId(0xd1)] int Height { get; set; } [DispId(210)] string LocationName { get; } [DispId(0xd3)] string LocationURL { get; } [DispId(0xd4)] bool Busy { get; } [DispId(300)] void Quit(); [DispId(0x12d)] void ClientToWindow(out int pcx, out int pcy); [DispId(0x12e)] void PutProperty([In] string property, [In] object vtValue); [DispId(0x12f)] object GetProperty([In] string property); [DispId(0)] string Name { get; } [DispId(-515)] int HWND { get; } [DispId(400)] string FullName { get; } [DispId(0x191)] string Path { get; } [DispId(0x192)] bool Visible { get; set; } [DispId(0x193)] bool StatusBar { get; set; } [DispId(0x194)] string StatusText { get; set; } [DispId(0x195)] int ToolBar { get; set; } [DispId(0x196)] bool MenuBar { get; set; } [DispId(0x197)] bool FullScreen { get; set; } [DispId(500)] void Navigate2([In] ref object URL, [In] ref object flags, [In] ref object targetFrameName, [In] ref object postData, [In] ref object headers); [DispId(0x1f5)] OLECMDF QueryStatusWB([In] OLECMDID cmdID); [DispId(0x1f6)] void ExecWB([In] OLECMDID cmdID, [In] OLECMDEXECOPT cmdexecopt, ref object pvaIn, IntPtr pvaOut); [DispId(0x1f7)] void ShowBrowserBar([In] ref object pvaClsid, [In] ref object pvarShow, [In] ref object pvarSize); [DispId(-525)] WebBrowserReadyState ReadyState { get; } [DispId(550)] bool Offline { get; set; } [DispId(0x227)] bool Silent { get; set; } [DispId(0x228)] bool RegisterAsBrowser { get; set; } [DispId(0x229)] bool RegisterAsDropTarget { get; set; } [DispId(0x22a)] bool TheaterMode { get; set; } [DispId(0x22b)] bool AddressBar { get; set; } [DispId(0x22c)] bool Resizable { get; set; } } class CorssDomainHelper { private static Guid IID_IWebBrowserApp = new Guid("0002DF05-0000-0000-C000-000000000046"); private static Guid IID_IWebBrowser2 = new Guid("D30C1661-CDAF-11D0-8A3E-00C04FC9E26E"); // Utility for IE cross domain access // Returns null in case of failure. public static IHTMLDocument3 GetDocumentFromWindow(IHTMLWindow2 htmlWindow) { if (htmlWindow == null) { return null; } // First try the usual way to get the document. try { IHTMLDocument2 doc = htmlWindow.document; return (IHTMLDocument3)doc; } catch (COMException comEx) { // I think COMException won't be ever fired but just to be sure ... } catch (UnauthorizedAccessException) { } catch (Exception ex) { return null; } // At this point the error was E_ACCESSDENIED because the frame contains a document from another domain. // IE tries to prevent a cross frame scripting security issue. try { // Convert IHTMLWindow2 to IWebBrowser2 using IServiceProvider. IServiceProvider sp = (IServiceProvider)htmlWindow; // Use IServiceProvider.QueryService to get IWebBrowser2 object. Object brws = null; sp.QueryService(ref IID_IWebBrowserApp, ref IID_IWebBrowser2, out brws); // Get the document from IWebBrowser2. IWebBrowser2 browser = (IWebBrowser2)(brws); return (IHTMLDocument3)browser.Document; } catch (Exception ex) { Console.WriteLine(ex); } return null; } } } |
使用的时候方法是这样的：
| HTMLDocument doc = (HTMLDocument)Browser.Document.DomDocument;
for (int i = 0; i < Browser.Document.Window.Frames.Count; i++) { IHTMLDocument3 baiduDoc = CorssDomainHelper.GetDocumentFromWindow(Browser.Document.Window.Frames[i].DomWindow as IHTMLWindow2); if (baiduDoc!=null && baiduDoc.documentElement!=null && baiduDoc.documentElement.document != null) { IHTMLElementCollection linkss = ((HTMLDocument)(baiduDoc.documentElement.document)).links; foreach (mshtml.IHTMLElement element in linkss) { //加入你的代码就可以了。 } } |
测试完全可以解决webbrowser 跨域访问iframe的问题。