How to detect crashing tabed webbrowser and handle it?
- by David Eaton
I have a desktop application (forms) with a tab control, I assign a tab and a new custom webrowser control. I open up about 10 of these tabs. Each one visits about 100 - 500 different pages.
The trouble is that if 1 webbrowser control has a problem it shuts down the entire program.
I want to be able to close the offending webbrowser control and open a new one in it's place.
Is there any event that I need to subscribe to catch a crashing or unresponsive webbrowser control ?
I am using C# on windows 7 (Forms), .NET framework v4
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UPDATE: 1 - The Tabbed WebBrowser Example
Here is the code I have and How I use the webbrowser control in the most basic way.
Create a new forms project and name it SimpleWeb
Add a new class and name it myWeb.cs, here is the code to use.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Security.Policy;
namespace SimpleWeb
{
//inhert all of webbrowser
class myWeb : WebBrowser
{
public myWeb()
{
//no javascript errors
this.ScriptErrorsSuppressed = true;
//Something we want set?
AssignEvents();
}
//keep near the top
private void AssignEvents()
{
//assign WebBrowser events to our custom methods
Navigated += myWeb_Navigated;
DocumentCompleted += myWeb_DocumentCompleted;
Navigating += myWeb_Navigating;
NewWindow += myWeb_NewWindow;
}
#region Events
//List of events:http://msdn.microsoft.com/en-us/library/system.windows.forms.webbrowser_events%28v=vs.100%29.aspx
//Fired when a new windows opens
private void myWeb_NewWindow(object sender, System.ComponentModel.CancelEventArgs e)
{
//cancel all popup windows
e.Cancel = true;
//beep to let you know canceled new window
Console.Beep(9000, 200);
}
//Fired before page is navigated (not sure if its before or during?)
private void myWeb_Navigating(object sender, System.Windows.Forms.WebBrowserNavigatingEventArgs args)
{
}
//Fired after page is navigated (but not loaded)
private void myWeb_Navigated(object sender, System.Windows.Forms.WebBrowserNavigatedEventArgs args)
{
}
//Fired after page is loaded (Catch 22 - Iframes could be considered a page, can fire more than once. Ads are good examples)
private void myWeb_DocumentCompleted(System.Object sender, System.Windows.Forms.WebBrowserDocumentCompletedEventArgs args)
{
}
#endregion
//Answer supplied by mo. (modified)?
public void OpenUrl(string url)
{
try
{
//this.OpenUrl(url);
this.Navigate(url);
}
catch (Exception ex)
{
MessageBox.Show("Your App Crashed! Because = " + ex.ToString());
//MyApplication.HandleException(ex);
}
}
//Keep near the bottom
private void RemoveEvents()
{
//Remove Events
Navigated -= myWeb_Navigated;
DocumentCompleted -= myWeb_DocumentCompleted;
Navigating -= myWeb_Navigating;
NewWindow -= myWeb_NewWindow;
}
}
}
On Form1 drag a standard tabControl and set the dock to fill, you can go into the tab collection and delete the pre-populated tabs if you like.
Right Click on Form1 and Select "View Code" and replace it with this code.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using mshtml;
namespace SimpleWeb
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
//Load Up 10 Tabs
for (int i = 0; i <= 10; i++)
{
newTab("Test_" + i, "http://wwww.yahoo.com");
}
}
private void newTab(string Title, String Url)
{
//Create a new Tab
TabPage newTab = new TabPage();
newTab.Name = Title;
newTab.Text = Title;
//create webbrowser Instance
myWeb newWeb = new myWeb();
//Add webbrowser to new tab
newTab.Controls.Add(newWeb);
newWeb.Dock = DockStyle.Fill;
//Add New Tab to Tab Pages
tabControl1.TabPages.Add(newTab);
newWeb.OpenUrl(Url);
}
}
}
Save and Run the project.
Using the answer below by mo. , you can surf the first url with no problem, but what about all the urls the user clicks on? How do we check those?
I prefer not to add events to every single html element on a page, there has to be a way to run the new urls thru the function OpenUrl before it navigates without having an endless loop.
Thanks.
