Jua*_*uan 11 c# browser winforms
我正在研究一个有时需要记住特定页面的Web抓取工具,然后转到其他页面,然后返回到该页面.目前我只保存页面的网址,但这对于Google地图这样的网页不起作用,其中网址始终相同.
我可以看到该GoBack方法确实返回到上一页,所以不知何故WebBrowser记得以前的页面是什么.我该如何手动完成此操作？我可以计算自从我想要返回的页面以来已经访问了多少页面,然后GoBack根据需要多次调用,但这是非常不可靠和不优雅的.所以我想知道如何实现一个GoBackToAParticularPage方法.
我认为有一件事可以让我更接近解决方案:保存所有帧的URL,然后在返回该页面时将它们放回原处.我认为这将解决谷歌地图问题.我还没有测试过.我不确切知道这样做的正确方法是什么.在设置URL之前,我需要等待帧存在.
您可以使用
webBrowser1.Document.Window.History.Go(x);
其中x是一个int,表示浏览器历史记录中的相对位置.
x = -2会导航两页.
更新:有关HtmlHistory.Go()的更多信息
如果其他人可以从中受益，这就是我最终的做法。唯一需要注意的是，如果旅行日志之间有太多页面，则该条目可能不再存在。可能有一种方法可以增加历史记录的大小，但由于必须有一些限制，所以我使用该TravelLog.GetTravelLogEntries方法来查看该条目是否仍然存在，如果不存在，则使用 URL 代替。
大部分代码来自PInvoke。
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Collections.Generic;
namespace TravelLogUtils
{
[ComVisible(true), ComImport()]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[GuidAttribute("7EBFDD87-AD18-11d3-A4C5-00C04F72D6B8")]
public interface ITravelLogEntry
{
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int GetTitle([Out] out IntPtr ppszTitle); //LPOLESTR LPWSTR
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int GetURL([Out] out IntPtr ppszURL); //LPOLESTR LPWSTR
}
[ComVisible(true), ComImport()]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[GuidAttribute("7EBFDD85-AD18-11d3-A4C5-00C04F72D6B8")]
public interface IEnumTravelLogEntry
{
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int Next(
[In, MarshalAs(UnmanagedType.U4)] int celt,
[Out] out ITravelLogEntry rgelt,
[Out, MarshalAs(UnmanagedType.U4)] out int pceltFetched);
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int Skip([In, MarshalAs(UnmanagedType.U4)] int celt);
void Reset();
void Clone([Out] out ITravelLogEntry ppenum);
}
public enum TLMENUF
{
/// <summary>
/// Enumeration should include the current travel log entry.
/// </summary>
TLEF_RELATIVE_INCLUDE_CURRENT = 0x00000001,
/// <summary>
/// Enumeration should include entries before the current entry.
/// </summary>
TLEF_RELATIVE_BACK = 0x00000010,
/// <summary>
/// Enumeration should include entries after the current entry.
/// </summary>
TLEF_RELATIVE_FORE = 0x00000020,
/// <summary>
/// Enumeration should include entries which cannot be navigated to.
/// </summary>
TLEF_INCLUDE_UNINVOKEABLE = 0x00000040,
/// <summary>
/// Enumeration should include all invokable entries.
/// </summary>
TLEF_ABSOLUTE = 0x00000031
}
[ComVisible(true), ComImport()]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[GuidAttribute("7EBFDD80-AD18-11d3-A4C5-00C04F72D6B8")]
public interface ITravelLogStg
{
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int CreateEntry([In, MarshalAs(UnmanagedType.LPWStr)] string pszUrl,
[In, MarshalAs(UnmanagedType.LPWStr)] string pszTitle,
[In] ITravelLogEntry ptleRelativeTo,
[In, MarshalAs(UnmanagedType.Bool)] bool fPrepend,
[Out] out ITravelLogEntry pptle);
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int TravelTo([In] ITravelLogEntry ptle);
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int EnumEntries([In] int TLENUMF_flags, [Out] out IEnumTravelLogEntry ppenum);
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int FindEntries([In] int TLENUMF_flags,
[In, MarshalAs(UnmanagedType.LPWStr)] string pszUrl,
[Out] out IEnumTravelLogEntry ppenum);
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int GetCount([In] int TLENUMF_flags, [Out] out int pcEntries);
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int RemoveEntry([In] ITravelLogEntry ptle);
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int GetRelativeEntry([In] int iOffset, [Out] out ITravelLogEntry ptle);
}
[ComImport, ComVisible(true)]
[Guid("6d5140c1-7436-11ce-8034-00aa006009fa")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IServiceProvider
{
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int QueryService(
[In] ref Guid guidService,
[In] ref Guid riid,
[Out] out IntPtr ppvObject);
}
public class TravelLog
{
public static Guid IID_ITravelLogStg = new Guid("7EBFDD80-AD18-11d3-A4C5-00C04F72D6B8");
public static Guid SID_STravelLogCursor = new Guid("7EBFDD80-AD18-11d3-A4C5-00C04F72D6B8");
//public static void TravelTo(WebBrowser webBrowser, int
public static ITravelLogEntry GetTravelLogEntry(WebBrowser webBrowser)
{
int HRESULT_OK = 0;
SHDocVw.IWebBrowser2 axWebBrowser = (SHDocVw.IWebBrowser2)webBrowser.ActiveXInstance;
IServiceProvider psp = axWebBrowser as IServiceProvider;
if (psp == null) throw new Exception("Could not get IServiceProvider.");
IntPtr oret = IntPtr.Zero;
int hr = psp.QueryService(ref SID_STravelLogCursor, ref IID_ITravelLogStg, out oret);
if ((oret == IntPtr.Zero) || (hr != HRESULT_OK)) throw new Exception("Failed to query service.");
ITravelLogStg tlstg = Marshal.GetObjectForIUnknown(oret) as ITravelLogStg;
if (null == tlstg) throw new Exception("Failed to get ITravelLogStg");
ITravelLogEntry ptle = null;
hr = tlstg.GetRelativeEntry(0, out ptle);
if (hr != HRESULT_OK) throw new Exception("Failed to get travel log entry with error " + hr.ToString("X"));
Marshal.ReleaseComObject(tlstg);
return ptle;
}
public static void TravelToTravelLogEntry(WebBrowser webBrowser, ITravelLogEntry travelLogEntry)
{
int HRESULT_OK = 0;
SHDocVw.IWebBrowser2 axWebBrowser = (SHDocVw.IWebBrowser2)webBrowser.ActiveXInstance;
IServiceProvider psp = axWebBrowser as IServiceProvider;
if (psp == null) throw new Exception("Could not get IServiceProvider.");
IntPtr oret = IntPtr.Zero;
int hr = psp.QueryService(ref SID_STravelLogCursor, ref IID_ITravelLogStg, out oret);
if ((oret == IntPtr.Zero) || (hr != HRESULT_OK)) throw new Exception("Failed to query service.");
ITravelLogStg tlstg = Marshal.GetObjectForIUnknown(oret) as ITravelLogStg;
if (null == tlstg) throw new Exception("Failed to get ITravelLogStg");
hr = tlstg.TravelTo(travelLogEntry);
if (hr != HRESULT_OK) throw new Exception("Failed to travel to log entry with error " + hr.ToString("X"));
Marshal.ReleaseComObject(tlstg);
}
public static HashSet<ITravelLogEntry> GetTravelLogEntries(WebBrowser webBrowser)
{
int HRESULT_OK = 0;
SHDocVw.IWebBrowser2 axWebBrowser = (SHDocVw.IWebBrowser2)webBrowser.ActiveXInstance;
IServiceProvider psp = axWebBrowser as IServiceProvider;
if (psp == null) throw new Exception("Could not get IServiceProvider.");
IntPtr oret = IntPtr.Zero;
int hr = psp.QueryService(ref SID_STravelLogCursor, ref IID_ITravelLogStg, out oret);
if ((oret == IntPtr.Zero) || (hr != HRESULT_OK)) throw new Exception("Failed to query service.");
ITravelLogStg tlstg = Marshal.GetObjectForIUnknown(oret) as ITravelLogStg;
if (null == tlstg) throw new Exception("Failed to get ITravelLogStg");
//Enum the travel log entries
IEnumTravelLogEntry penumtle = null;
tlstg.EnumEntries((int)TLMENUF.TLEF_ABSOLUTE, out penumtle);
hr = 0;
ITravelLogEntry ptle = null;
int fetched = 0;
const int MAX_FETCH_COUNT = 1;
hr = penumtle.Next(MAX_FETCH_COUNT, out ptle, out fetched);
Marshal.ThrowExceptionForHR(hr);
HashSet<ITravelLogEntry> results = new HashSet<ITravelLogEntry>();
for (int i = 0; 0 == hr; i++)
{
if (ptle != null) results.Add(ptle);
hr = penumtle.Next(MAX_FETCH_COUNT, out ptle, out fetched);
Marshal.ThrowExceptionForHR(hr);
}
Marshal.ReleaseComObject(penumtle);
Marshal.ReleaseComObject(tlstg);
return results;
}
}
}