C Sharp Flags: Difference between revisions

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This page was last edited on 9 December 2012, at 19:06.
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Created page with "== Defining Flags == [Flags] public enum State { Idle = 0x01, Available = 0x02, InService = 0x04, Accelerating = 0x08, Decelerating = 0x10, Sto..."
 
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  state = state | State.Stopped;
  state = state | State.Stopped;
   
   
<code>state</code> now has both Available and Stopped. The actual value of <code>state</state> is 0x22 (from 0x02 + 0x22)
<code>state</code> now has both Available and Stopped. The actual value of <code>state</code> is 0x22 (from 0x02 + 0x22)


=== Removing a Flag ===
=== Removing a Flag ===

Revision as of 19:06, 9 December 2012

Defining Flags

[Flags]
public enum  State {
   Idle = 0x01,
   Available = 0x02,
   InService = 0x04,
   
   Accelerating = 0x08,
   Decelerating = 0x10,
   Stopped = 0x20,
}

Notice that the flags are given values of powers of two.

Operations

Setting a Flag

Use the bit-wise OR operation to set (add) a flag. 

State state = State.Available;
state = state | State.Stopped;

state now has both Available and Stopped. The actual value of state is 0x22 (from 0x02 + 0x22)

Removing a Flag

Use the bit-wise XOR (^) operation to unset (remove) a flag. 

State state = State.Available | State.Stopped;
state = state ^ State.Available;
state = state ^ State.Stopped;
state = state | State.InService;

state is now InService. The actual value of state</state> is 0x04.


Checking

Use the bit-wise AND operation to do checking. 

State state = State.Available | State.Stopped;

if (state & State.Idle == State.Idle) {
   // This will fail as state is set to Available and Stopped.
}