获取基于Internet Explorer_Server的聊天窗口内容

假设在得到窗体中控件的句柄（通过SPY++）的前提下，如果是像文本框这种控件，只要用SendMessage就可得到文本了，但是对于聊天记录窗口却行不通（返回空值），因为那其实是一个内置浏览器Internet Explorer_Server 

经查询，可用以下方式获取：

先引用：mshtml

 

using System;

using System.Collections.Generic;

using System.Text;

using System.Runtime.InteropServices;

using mshtml;

 

   [Flags]

    public enum SendMessageTimeoutFlags : uint

    {

        SMTO_NORMAL = 0x0,

        SMTO_BLOCK = 0x1,

        SMTO_ABORTIFHUNG = 0x2,

        SMTO_NOTIMEOUTIFNOTHUNG = 0x8

    }

 

public class WinAPI 

{

        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]

        static extern uint RegisterWindowMessage(string lpString);      

 

        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]

        private static extern IntPtr SendMessageTimeout(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam, SendMessageTimeoutFlags flags, uint timeout, out UIntPtr result);

 

        [DllImport("oleacc.dll", PreserveSig = false)]

        [return: MarshalAs(UnmanagedType.Interface)]

        private static extern object ObjectFromLresult(UIntPtr lResult, [MarshalAs(UnmanagedType.LPStruct)] Guid refiid, IntPtr wParam);

 

        public IHTMLDocument2 GetHtmlDocument(IntPtr hWnd)

        {           

            uint lMsg = RegisterWindowMessage("WM_HTML_GETOBJECT");

 

            UIntPtr lRes;         

            SendMessageTimeout(hWnd, lMsg, IntPtr.Zero, IntPtr.Zero, SendMessageTimeoutFlags.SMTO_ABORTIFHUNG, 1000, out lRes);

 

            IHTMLDocument2 htmlDoc = null;

            if (lRes != UIntPtr.Zero)

            {

                htmlDoc = (IHTMLDocument2)ObjectFromLresult(lRes, typeof(IHTMLDocument2).GUID, IntPtr.Zero);

            }

 

            return htmlDoc;

        }

 

        public string GetWebText(IntPtr hWnd)

        {

            IHTMLDocument2 htmlDoc = GetHtmlDocument(hWnd);

            if (htmlDoc != null)

            {

                return htmlDoc.body.innerHTML;

            }

            else

            {

                return string.Empty;

            }

        }

}