Επεξεργασία

Κοινή χρήση μέσω

WebBrowser.CanGoBackChanged Event

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll
Source:
WebBrowser.cs
Source:
WebBrowser.cs
Source:
WebBrowser.cs

Occurs when the CanGoBack property value changes.

public:
 event EventHandler ^ CanGoBackChanged;
[System.ComponentModel.Browsable(false)]
public event EventHandler CanGoBackChanged;
[System.ComponentModel.Browsable(false)]
public event EventHandler? CanGoBackChanged;
[<System.ComponentModel.Browsable(false)>]
member this.CanGoBackChanged : EventHandler 
Public Custom Event CanGoBackChanged As EventHandler 
Public Event CanGoBackChanged As EventHandler

Event Type

EventHandler
Attributes
BrowsableAttribute

Examples

The following code example demonstrates how to use a handler for the CanGoBackChanged event to implement a Back button for the WebBrowser control similar to the one in Internet Explorer. This example requires that your form contains a WebBrowser control called webBrowser1 and a Button control called backButton.

For the complete code example, see How to: Add Web Browser Capabilities to a Windows Forms Application.

// Navigates WebBrowser1 to the previous page in the history.
void backButton_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
   this->WebBrowser1->GoBack();
}

// Disables the Back button at the beginning of the navigation history.
void WebBrowser1_CanGoBackChanged( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
   this->backButton->Enabled = this->WebBrowser1->CanGoBack;
}

// Navigates webBrowser1 to the previous page in the history.
private void backButton_Click(object sender, EventArgs e)
{
    webBrowser1.GoBack();
}

// Disables the Back button at the beginning of the navigation history.
private void webBrowser1_CanGoBackChanged(object sender, EventArgs e)
{
    backButton.Enabled = webBrowser1.CanGoBack;
}

' Navigates webBrowser1 to the previous page in the history.
Private Sub backButton_Click( _
    ByVal sender As Object, ByVal e As EventArgs) _
    Handles backButton.Click

    webBrowser1.GoBack()

End Sub

' Disables the Back button at the beginning of the navigation history.
Private Sub webBrowser1_CanGoBackChanged( _
    ByVal sender As Object, ByVal e As EventArgs) _
    Handles webBrowser1.CanGoBackChanged

    backButton.Enabled = webBrowser1.CanGoBack

End Sub

Remarks

The WebBrowser control maintains a history list of all the Web pages visited during a browsing session. The GoBack method navigates the WebBrowser control to the previous page in this history, if one is available. The CanGoBack property indicates whether navigation history is available and contains a previous page. Handle the CanGoBackChanged event to receive a notification when the CanGoBack property changes. Handling this event is useful, for example, to change the enabled state of a Back button when the WebBrowser control navigates to or leaves the beginning of the navigation history.

For more information about handling events, see Handling and Raising Events.

Applies to

See also