When hosting the WebBrowser control, it may be desirable to implement
Forward and Back buttons similar to those that Internet Explorer
implements. One common problem that programmers face when doing this is how
to know when to enable and disable the buttons.
The WebBrowser control supports a CommandStateChange event, which is fired
whenever the Forward or Back buttons need to be enabled or disabled. The
CommandStateChange event is sent with two parameters: a constant indicating
the type of button (CSC_NAVIGATEFORWARD or CSC_NAVIGATEBACK), and a Boolean
flag indicating whether to enable or disable the button.
CSC_NAVIGATEFORWARD and CSC_NAVIGATEBACK are defined in Exdisp.h, which
comes with the Internet Client SDK.
// For an MFC application the CommandStateChange event could be handled
// as follows:
#include <exdisp.h>
void CBrowserDlg::OnCommandStateChangeExplorer1(long Command, BOOL Enable)
{
switch(Command)
{
case CSC_NAVIGATEFORWARD:
// m_ctlForward is a CButton type
m_ctlForward.EnableWindow(Enable);
break;
case CSC_NAVIGATEBACK:
m_ctlBack.EnableWindow(Enable);
break;
default:
break;
}
}
' A Visual Basic application can also implement this
' functionality in this manner:
Private Sub WebBrowser_CommandStateChange(ByVal Command As Long,ByVal Enable As Boolean)
Select Case Command
Case CSC_NAVIGATEBACK
Back.Enabled = Enable
Case CSC_NAVIGATEFORWARD
Forward.Enabled = Enable
End Select
End Sub
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