when and how to use QueryString["ReturnUrl"]

1. when ASP.NET will create QueryString["ReturnUrl"]?

2. how to use it? i mean could you give me seve开发者_JS百科ral typical situation when using QueryString["ReturnUrl"]?

The ReturnUrl is passed around by ASP.NET as part of the default .Net authentication scheme. It's designed to check for this parameter and automatically redirect after authentication to take the user back to their original destination.

You generally don't need to use it, unless you are overriding the default authentication mechanisms in .Net, or using it for your own purpose.