In ASP.NET, there isn't a file called global.asa. The global.asa file was used in classic ASP (Active Server Pages) for application-level events and settings. However, in ASP.NET, you use the Global.asax file for similar purposes.
The Global.asax file is an optional file that contains code for responding to application-level events raised by ASP.NET or by HttpModules. It serves as a central location for handling application-level events and can contain code for application startup, shutdown, session start, session end, error handling, etc.
Here's a simple example demonstrating how you might use Global.asax:
Example
<%@ Application Language="C#" %>
<script runat="server">
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup
Application["AppStartTime"] = DateTime.Now;
}
void Application_End(object sender, EventArgs e)
{
// Code that runs on application shutdown
}
void Session_Start(object sender, EventArgs e)
{
// Code that runs when a new session is started
}
void Session_End(object sender, EventArgs e)
{
// Code that runs when a session ends
}
void Application_Error(object sender, EventArgs e)
{
// Code that runs when an unhandled error occurs
}
</script>
In this example:
Application_Start: This event is triggered when the application starts (i.e., when the first request is received by the application). Here, we're storing the application start time in the Application state.Application_End: This event is triggered when the application shuts down (i.e., when the application domain is unloaded).Session_Start: This event is triggered when a new session is started.Session_End: This event is triggered when a session ends (e.g., when the session expires or is explicitly abandoned).Application_Error: This event is triggered when an unhandled error occurs anywhere in the application.You can add code to these event handlers to perform tasks specific to your application, such as initializing application-wide resources, logging events, handling errors, etc.
Remember, Global.asax is a powerful file for managing application-level events and behavior in ASP.NET applications.