Enum.GetUnderlyingType Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Returns the underlying type of the specified enumeration.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- enumType
- Type: System.Type
The enumeration whose underlying type will be retrieved.
| Exception | Condition |
|---|---|
| ArgumentNullException | enumType is Nothing. |
| ArgumentException | enumType is not an Enum. |
The Enum structure enables values to be represented as named constants. The data type of the enumeration's values is known as its underlying type. For example, the underlying type of the DayOfWeek enumeration, which consists of constants that represent each day of the week (DayOfWeek.Monday, DayOfWeek.Tuesday, and so on), is Int32.
The following example calls the GetUnderlyingType method to display the underlying type of some enumeration members.
Module Example Public Sub Demo(outputBlock As System.Windows.Controls.TextBlock) Dim enumValues() As [Enum] = { DayOfWeek.Monday, PlatformID.Win32NT, DateTimeKind.Utc, StringComparison.Ordinal } outputBlock.FontFamily = New FontFamily("Courier New") outputBlock.Text += String.Format("{0,-10} {1, 18} {2,15}", "Member", "Enumeration", "Underlying Type") + vbCrLf outputBlock.Text += vbCrLf For Each enumValue In enumValues DisplayEnumInfo(outputBlock, enumValue) Next End Sub Sub DisplayEnumInfo(outputBlock As System.Windows.Controls.TextBlock, enumValue As [Enum]) Dim enumType As Type = enumValue.GetType() Dim underlyingType As Type = [Enum].GetUnderlyingType(enumType) outputBlock.Text += String.Format("{0,-10} {1, 18} {2,15}", enumValue, enumType.Name, underlyingType.Name) + vbCrLf End Sub End Module ' The example displays the following output: ' Member Enumeration Underlying Type ' ' Monday DayOfWeek Int32 ' Win32NT PlatformID Int32 ' Utc DateTimeKind Int32 ' Ordinal StringComparison Int32