Switch on Enum (with Flags attribute) without declaring every possible combination?

Question

how do i switch on an enum which have the flags attribute set (or more precisely is used for bit operations) ?

I want to be able to hit all cases in a switch that matche

Answer 1

The easiest way is to just perform an ORed enum, in your case you could do the following :

[Flags()]public enum CheckType
{
    Form = 1,   
    QueryString = 2,
    TempData = 4,
    FormQueryString = Form | QueryString,
    QueryStringTempData = QueryString | TempData,
    All = FormQueryString | TempData
}

Once you have the enum setup its now easy to perform your switch statement.

E.g, if i have set the following :

var chkType = CheckType.Form | CheckType.QueryString;

I can use the following switch statement as follows :

switch(chkType){
 case CheckType.Form:
   // Have Form
 break;
 case CheckType.QueryString:
   // Have QueryString
 break;
 case CheckType.TempData:
  // Have TempData
 break;
 case CheckType.FormQueryString:
  // Have both Form and QueryString
 break;
 case CheckType.QueryStringTempData:
  // Have both QueryString and TempData
 break;
 case CheckType.All:
  // All bit options are set
 break;
}

Much cleaner and you don't need to use an if statement with HasFlag. You can make any combinations you want and then make the switch statement easy to read.

I would recommend breaking apart your enums, try see if you are not mixing different things into the same enum. You could setup multiple enums to reduce the number of cases.