Get Object Reference Error when trying to use Request.QueryString
This question already has an answer here:
你需要检查空值
if (Request.QueryString["id"] != null && Request.QueryString["id"].Equals("1"))
{
//Do something
}
You can do this:
if(Request.QueryString.Length != 0)
{
...
}
If you try to access elements which are not present, you'll receive an exception. So, since QueryString has a property of Length , checking it against 0 means there is no query string at all.
Else if you want to know that only if id key isn't present, you can do this:
if(Request.QueryString.AllKeys.Contains("id"))
{
}
Try this:
if (Request.QueryString["id"] != null && Request.QueryString["id"].Equals("1"))
{
//Do something
}
Another way :
string id = Request.QueryString["id"] ?? "";
if(id == "1")
{
//Do something
}