Introduction
Everyone knows that there is currently a popular web browser such as Mozilla Firefox and Myie2, with multi-page browsing feature, each open a new page automatically generates a new tab page, and the shutdown of the page is very simple. This design idea makes the user very simple when browsing multiple web pages, and avoids the user's distress waiting for a single page. Since these browsers generally support operation of multiple file formats, it is also very convenient when browsing multiple files on the local machine.
This article uses Visual C to describe how to implement this multi-page browsing feature. At the same time, the following additional features are also implemented: print, print preview, page properties, options, lookups, view page source files, etc.
Key technical analysis
The key to solving the problem is the programming of the NewWindow2 event for the browser control webbrowser. When a file is required to generate a new window, the NewWindow2 event is activated. Note that the event occurs before the new window of the WebBrowser control. For example, the event occurs as a response to a new window or a new window or a script-controlled Window.Open method. To declare that when a new window is opened, we will use our own browser programs to set the parameter PPDISP as an Application object. At this point, if you choose
"
Open in a new window
"
Then, a window is generated to display the web page. You can also set the RegisterAsBrowser to TRUE, which will cause the newly generated WebBrowser control to participate in the conflict of the window named. For example, if the name of a window is used in another place in the script, then the control is sent to the field, not a new window, because the control checks all existing windows before opening a new window. Name to avoid naming conflicts. In this example, as a response to the event, we dynamically create a TAB page, and generate a webbrowser control as its sub-control by calling the CreateNewwebBrowser () method - each sub-control has a control related information. TAG attribute. See the source code below for details:
Private
Void
AxWebBrowser1_newwindow2 (
Object
Sender, axshdocvw.dwebbrowserevents2_newwindow2event e)
{
Axshdocvw.axwebbrowser_axwebbrowser
=
CreateNewwebBrowser ();
E.ppdisp
=
_axwebbrowser.Application;
_AXWebBrowser.registerAsBrowser
=
True
;
}
Private
Axshdocvw.axwebbrowser CreateNewwebBrowser ()
{
Axshdocvw.axwebbrowser_axwebbrowser
=
New
Axshdocvw.axwebbrowser ();
_AXwebbrowser.tag
=
New
HE_WEBBROWSERTAG ();
Tabpage_tabpage
=
New
TabPage ();
_Tabpage.controls.add (_axwebbrowser);
_axwebbrowser.dock
=
DockStyle.Fill;
_axwebbrowser.beforenavigate2
=
New
AXSHDOCVW.DWEBBBROWSEREVENTS2_BEFORENAVIGATE2EVENTHANDLER
(
THIS
.axwebbrowser1_beforenavigate2;
_axwebbrowser.documentcomplete
=
New
AXSHDOCVW.DWEBBBBBROWSEREVENTS2_DocumentCompleteEventhandler
(
THIS
.axwebbrowser1_documentcomplete);
_axwebbrowser.navigateComplete2
=
New
Axshdocvw.dwebbrowserevents2_navigatecomplete2eventhandler
(
THIS
.axwebbrowser1_navigateComplete2);
_axwebbrowser.navigateerror
=
New
Axshdocvw.dwebbrowserevents2_navigateerRoreventhandler
(
THIS
.axwebbrowser1_navigate;
_axwebbrowser.newwindow2
=
New
Axshdocvw.dwebbrowserevents2_newwindow2eventhandler
(
THIS
.axwebbrowser1_newwindow2;
_axwebbrowser.progresschange
=
New
Axshdocvw.dwebbrowserevents2_progresschangeeventhandler
(
THIS
.axwebbrowser1_progresschange);
_axwebbrowser.statustextchange
=
New
Axshdocvw.dwebbrowserevents2_statustextchangeeventhandler
(
THIS
.axwebbrowser1_statustextchange;
_axwebbrowser.titlechange
=
New
Axshdocvw.dwebbrowserevents2_titlechangeeeventhandler
(
THIS
.axwebbrowser1_titlechange);
_axwebbrowser.commandStateChange
=
New
AXSHDOCVW.DWEBBBROWSEREVENTS2_COMMANDSTATECHANGEVENTHANDLER
(
THIS
.axwebbrowser1_commandstatechange);
TabControl1.Tabpages.Add (_tabpage);
TabControl1.selectedTAB
=
_Tabpage;
Return
_axwebbrowser;
}
Note that every WebBrowser control has a tag, which is defined as a simple class, which is used to contain some of the unique information related to this control. Please see:
public
Class
HE_WebBrowsertag
{
public
int
_Tabindex
=
0
;
public
Bool
_CANBACK
=
False
;
public
Bool
_CANFORWARD
=
False
;
}
achieve
"
Look up
"
,
"
View page source files
"
,
"
Option
"
Dialog, etc.
A unprecedented GUID is used in this routine, which can change in the future system.
1, define the IOLCOMMANDTARGET interface
To define a .NET interface to get a reference about a COM interface, follow these steps:
1) GUID value of the COM interface corresponding to the .NET interface;
2) Contains the type declaration of all methods in the interface;
3) Contains a reference to MSHTML.DLL and SHDOCVW.DLL files, in Visual C .NET project, follow: a. Click on the project menu
"
Add a reference
"
;
B. Click
"
COM
"
Tab;
C. Double click
"
Microsoft HTML Object Library
"
with
"
Microsoft Internet Controls
"
.
4) Before the program namespace declaration, the following interface declaration should be added to add reference references to Microsoft HTML (MSHTML) IOLCOMMANDTARGET interface:
Using
System;
Using
System.Runtime.InteropServices;
[StructLayout (layoutkind.sequential, charset
=
Charset.Unicode)]
public
Struct
OlecmdText
{
public
Uint
CmdTextf;
public
Uint
CWACTUAL;
public
Uint
CWBUF;
[Marshalas (UnmanagedType.Byvaltstr, SIZECONST
=
100
)]]
public
charr
RGWZ;
}
[Structlayout (layoutkind.sequential)]
public
Struct
OLECMD
{
public
Uint
CMDID;
public
Uint
CMDF;
}
//
Interop definition of IOLCOMMANDTARGET
[ComImport,
GUID
"
B722BCCB-4E68-101B-A2BC-00AA00404770
"
),
InterfacePe (CominterFactype.Interfaceisiunknown)]
public
Interface
IOLCOMMANDTARGET
{
Void
Querystatus
Ref
Guid pguidcmdgroup, uint32 ccmds,
[Marshalas (UnmanagedType.lparray, SizeParamindex
=
1
)]]
Olecmd [] prgcmds,
Ref
OLECMDTEXT CMDText);
Void
EXEC (
Ref
Guid pguidcmdgroup,
Uint
NCMDID,
Uint
NCMDEXECOPT,
Ref
Object
Pvain,
Ref
Object
pvaout);
}
2. Define a GUID for CGID_IWebBrowser
The GUID of the CGI_iWebBrowser must be defined to inform MSHTML how to handle your command ID. Implemented in .NET as follows:
Private
GUID CMDGUID
=
New
GUID
"
ED016940-BD5B-11CF-Ba4e-00c04fd70816
"
);
Private
ENUM
MisccommandTarget {Find
=
1
ViewSource, Options}
3, call the exec () method
Note that the following three processes successfully calls the premise of Exec (), there is already an inclusive instance of the browser control called WebBrowser.
Private
mshtml.htmldocument getDocument ()
{
Try
{
Mshtml.htmldocument HTM
=
(mshtml.htmldocument) AXWebBrowser2.document;
Return
HTM;
}
Catch {
Throw
(
New
EXCEPTION
"
You cannot get file objects from the webbrowser control
"
));
}
}
//
View the source code method
public
Void
ViewSource ()
{
IOLCMMANDTARGET CMDT;
Object O
=
New
Object
();
Try
{
cmdt
=
(Iolecommandtarget) getDocument ();
Cmdt.exec
Ref
Cmdguid,
Uint
) MiscCommandTarget.ViewSource,
(
Uint
) Shdocvw.olecmdexecopt.Olecmdexecopt_dodefault,
Ref
O,
Ref
o);
}
Catch
(Exception E)
{
System.windows.Forms.MessageBox.show (E.MESSAGE);
}
}
public
Void
Find ()
{
IOLCMMANDTARGET CMDT;
Object O
=
New
Object
();
Try
{
cmdt
=
(Iolecommandtarget) getDocument ();
Cmdt.exec
Ref
Cmdguid,
Uint
) MisccommandTarget.Find,
(
Uint
) Shdocvw.olecmdexecopt.Olecmdexecopt_dodefault,
Ref
O,
Ref
o);
}
Catch
(Exception E)
{
System.windows.Forms.MessageBox.show (E.MESSAGE);
}
}
//
Displays the method of "Options" dialog
public
Void
InternetOptions ()
{
IOLCMMANDTARGET CMDT;
Object O
=
New
Object
();
Try
{
cmdt
=
(Iolecommandtarget) getDocument ();
Cmdt.exec
Ref
Cmdguid,
Uint
) MisccommandTarget.Options,
(
Uint
) Shdocvw.olecmdexecopt.Olecmdexecopt_dodefault,
Ref
O,
Ref
o);
}
Catch
{
//
Note: Because the process corresponding to the CMDID is in Internet Explorer Processing
//
So the exception code block here will always be activated, even if the dialog is successful.
//
Of course, you can choose settings through the browser to ban such errors.
//
However, even if this prompt has, there is no harm to your host.
}
}
to sum up
This article uses VC # compiled, detail how to implement a multi-page browsing program. Welcome colleagues criticism.
