SP - How to check URL whether ID

Question

How to check current page URL address for null ID.. How to do this ?

This is my code, but not correct..

        private int id = -1;

        protected override void CreateChildControls()
        {
            try
            {
                if (SPContext.Current.ListItem != null)
                {
                    id = SPContext.Current.ListItem.ID;


                          MyLogic HERE.....
                 }
            }
         }

Answer 1

You can check it from QueryString in farm solution:

string id= Request.QueryString["ID"];

if (id != null)
{
//code goes here
}

In SandBoxed solution

string id= Page.Request.QueryString["ID"];

if (id != null)
{
//code goes here
}