Application_Error does not fire?

问题

In Webform1.aspx.cs:

protected void Page_Load(object sender, EventArgs e)
{
    throw new Exception("test exception");
}

In the Global.asax.cs:

protected void Application_Error(object sender, EventArgs e)
{
    // Code that runs when an unhandled error occurs
    if (Server.GetLastError() is HttpUnhandledException)
        Server.Transfer("ErrUnknown.aspx");
}

But the Application_Error event handler never gets called. Instead I get a runtime error page.

What do I have to do have Application_Error being called after an exception is thrown?

回答1:

It looks fine and the Application_Error should being called.

Did you checked by Debugging your application?

Actually you are missing Server.ClearError() so the exception is being passed to asp.net but you should suppress it here because you are handling it by yourself.

protected void Application_Error(object sender, EventArgs e)
{
    // Code that runs when an unhandled error occurs
    if (Server.GetLastError() is HttpUnhandledException)
    {
        // suppressing the error so it should not pass to asp.net
        Server.ClearError();
        Server.Transfer("ErrUnknown.aspx");
    }
}