Converting raw data type to enumerated type
- by Jim Lahman
There are times when an enumerated type is preferred over using the raw data type. An example of using a scheme is when we need to check the health of x-ray gauges in use on a production line. Rather than using a scheme like 0, 1 and 2, we can use an enumerated type: 1: /// <summary>
2: /// POR Healthy status indicator
3: /// </summary>
4: /// <remarks>The healthy status is for each POR x-ray gauge; each has its own status.</remarks>
5: [Flags]
6: public enum POR_HEALTH : short
7: {
8: /// <summary>
9: /// POR1 healthy status indicator
10: /// </summary>
11: POR1 = 0,
12: /// <summary>
13: /// POR2 healthy status indicator
14: /// </summary>
15: POR2 = 1,
16: /// <summary>
17: /// Both POR1 and POR2 healthy status indicator
18: /// </summary>
19: BOTH = 2
20: }
By using the [Flags] attribute, we are treating the enumerated type as a bit mask. We can then use bitwise operations such as AND, OR, NOT etc. .
Now, when we want to check the health of a specific gauge, we would rather use the name of the gauge than the numeric identity; it makes for better reading and programming practice.
To translate the numeric identity to the enumerated value, we use the Parse method of Enum class:
POR_HEALTH GaugeHealth = (POR_HEALTH) Enum.Parse(typeof(POR_HEALTH), XrayMsg.Gauge_ID.ToString());
The Parse method creates an instance of the enumerated type.
Now, we can use the name of the gauge rather than the numeric identity:
1: if (GaugeHealth == POR_HEALTH.POR1 || GaugeHealth == POR_HEALTH.BOTH)
2: {
3: XrayHealthyTag.Name = Properties.Settings.Default.POR1XRayHealthyTag;
4: }
5: else if (GaugeHealth == POR_HEALTH.POR2)
6: {
7: XrayHealthyTag.Name = Properties.Settings.Default.POR2XRayHealthyTag;
8: }