【下载文档:  使用C#处理WebBrowser控件在不同域名中的跨域问题.txt 】

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使用C#处理WebBrowser控件在不同域名中的跨域问题
我们在做web测试时，经常会使用WebBrowser来进行一些自动化的任务。而有些网页上面会用IFrame去嵌套别的页面，这些页面可能不是在相同域名下的，这时就会出现跨域问题，无法直接在WebBrowser中获取到IFrame中的元素。下面来做个试验，自己写个页面嵌套一个百度的首页，然后在我们自己的页面上输入要查询的词，最后在百度上自动完成搜索。 复制代码 代码如下: 下面再建一个简单的WinForm工程测试一下，界面如下： 下面就是WebBrowser的测试代码： 复制代码 代码如下:using System; using System.Windows.Forms; namespace WebBrowserTest { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { this.webBrowser1.Navigate(this.textBox1.Text); } private void button2_Click(object sender, EventArgs e) { var doc = this.webBrowser1.Document; var frames = doc.Window.Frames; String testValue = doc.GetElementById("search").GetAttribute("value"); frames[0].Document.GetElementById("kw").SetAttribute("value", testValue); frames[0].Document.GetElementById("su").InvokeMember("click"); } } }我们运行我们的测试程序后，加载之前我们自己写的页面后，在自己的页面上输入我们要查询的词，点击测试按钮，就会看到程序报未处理 UnauthorizedAccessException错误： 下面来编写一个Helper类来解决这个问题，主要原理大致就是利用IWebBrowser2这个接口来获取Ifream中的Dom，IWebBrowser2中的document可以转换为IHtmlDocument1，IHtmlDocument2，IHtmlDocument3。复制代码 代码如下: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; } } }最后将我们的运行代码改为如下形式，调用Helper类中的GetDocumentFromWindow方法： 复制代码 代码如下:using System; using System.Windows.Forms; using mshtml; namespace WebBrowserTest { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { this.webBrowser1.Navigate(this.textBox1.Text); } private void button2_Click(object sender, EventArgs e) { var doc = this.webBrowser1.Document; var frames = doc.Window.Frames; String testValue = doc.GetElementById("search").GetAttribute("value"); IHTMLDocument3 baiduDoc = CorssDomainHelper.GetDocumentFromWindow(frames[0].DomWindow as IHTMLWindow2); baiduDoc.getElementById("kw").setAttribute("value", testValue); baiduDoc.getElementById("su").click(); } } }最后运行一下程序可以看到我们可以正常获取到百度上的元素了。补充一下路过秋天说的问题： 其实关于这些接口其实我也没有很深入的研究过，不过网上倒是能搜到很多相关资料介绍这些接口的不同，我这里给一个链接： http://hi.baidu.com/christole/item/1c8dfd1a791a53643f87ced8 然后关于我上面的代码为什么要使用IHMLDocument3，而不是其它两个接口，因为IHMLDocument3这个接口里面定义了我需要的getElementById这个方法。 通过查看MSDN，你可以找到你需要的属性或者方法，然后直接在代码里面转换为你需要的类型使用就可以了，它们之间都是可以互相转化的。比如上面我用完了getElementById方法，我需要查看网页的title，那么可以将我上面的baiduDoc变量强制转为IHMLDocument2，然后就可以直接使用它的title属性了。 参考链接： http://msdn.microsoft.com/en-us/library/aa752052(v=vs.85).aspx http://codecentrix.blogspot.com/2007/10/when-ihtmlwindow2getdocument-returns.html http://msdn.microsoft.com/en-us/library/aa752641(v=VS.85).aspx