Problem | repeat
about how to prohibit the same user at the same time on different machines repeatedly landing the problem I think so, if there is a wrong place also please correct me, we discuss together.
Mainly want to solve the problem at the application level. The reason for not using the database is that the database is used to judge whether the landing is very expensive system resources, with application can solve the problem of resource consumption.
The overall idea is to set the user activity time and timeout, if the user in the specified timeout period is not active, it is considered that the user is offline, or abnormal offline (such as power). When the user exits the browser, triggering the Application_unload event, it can be set in the Global.asa, or the Javascript+ajax can be used to determine and perform an exit operation, and then perform application emptying when exiting. If you are using JavaScript to determine exit, you need to use Ajax to perform application emptying operations. Here is my main idea flow diagram.
SmartDraw 7 SDR source file Click here to download the source file