how many times is System.Web.HttpApplication is in

问题:

I have the global.asax which extends from a custom class I created, called MvcApplication which extends from System.Web.HttpApplication.

In it's constructor, it logs application start as per below:

protected MvcApplicationGeneral()
{
    _log.Info("logApplicationStartToTextFile");
}

When I went to look in the log file, this seems to be called A LOT of times, not just once per application start. I placed another log entry in Application_Start and that seems to be called only once. Is the Global.asax class instantiated per request, or much more frequently than just once per application?

回答1:

Multiple intances of HttpAppliction objects are created and pooled to process the requests.in the lifecycle of an asp.net application. yes Application_Start will be called only once.

refer http://www.codeproject.com/Articles/73728/ASP-NET-Application-and-Page-Life-Cycle

excerpt: Once all the core ASP.NET objects are created, ‘HttpApplication’ object is created to serve the request. In case you have a ‘global.asax’ file in your system, then the object of the ‘global.asax’ file will be created. Please note global.asax file inherits from ‘HttpApplication’ class. Note: The first time an ASP.NET page is attached to an application, a new instance of ‘HttpApplication’ is created. Said and done to maximize performance, HttpApplication instances might be reused for multiple requests.