关于viewstate

Question

好的，如果我想要这样的东西，ViewState["AddressID"]和ViewState["AddressID1"]都存储着AddressIDs..Now :-

if its ViewState["AddressID"]    
{
   call method 1
}

if its ViewState["AddressID1"]    
{
   call method 2
}

现在我如何检查它的ViewState["AddressID"]还是ViewState["AddressID1"]

Answer 1

string addressId = ViewState["AddressID"] as string;
string addressId1 = ViewState["AddressID1"] as string;
if (!string.IsNullOrEmpty(addressId))
{
    method1(addressId);
}
else if (!string.IsNullOrEmpty(addressId1))
{
    method2(addressId1);
}

Answer 2

如果ViewState键没有值，则为null，因此：

if (ViewState["AddressID"] != null) 
  Method1(ViewState["AddressID"] as string);
else 
  Method2(ViewState["AddressID1"] as string);