UnmanagedType Enumeration
Assembly: mscorlib (in mscorlib.dll)
'Declaration <SerializableAttribute> _ <ComVisibleAttribute(True)> _ Public Enumeration UnmanagedType 'Usage Dim instance As UnmanagedType
/** @attribute SerializableAttribute() */ /** @attribute ComVisibleAttribute(true) */ public enum UnmanagedType
SerializableAttribute ComVisibleAttribute(true) public enum UnmanagedType
| Member name | Description | |
|---|---|---|
![]() | AnsiBStr | An ANSI character string that is a length prefixed, single byte. You can use this member on the String data type. |
![]() | AsAny | A dynamic type that determines the type of an object at run time and marshals the object as that type. Valid for platform invoke methods only. |
![]() | Bool | A 4-byte Boolean value (true != 0, false = 0). This is the Win32 BOOL type. |
![]() | BStr | A Unicode character string that is a length-prefixed double byte. You can use this member, which is the default string in COM, on the String data type. |
![]() | ByValArray | When MarshalAsAttribute.Value is set to ByValArray, the SizeConst must be set to indicate the number of elements in the array. The ArraySubType field can optionally contain the UnmanagedType of the array elements when it is necessary to differentiate among string types. You can only use this UnmanagedType on an array that appear as fields in a structure. |
![]() | ByValTStr | Used for in-line, fixed-length character arrays that appear within a structure. The character type used with ByValTStr is determined by the System.Runtime.InteropServices.CharSet argument of the System.Runtime.InteropServices.StructLayoutAttribute applied to the containing structure. Always use the MarshalAsAttribute.SizeConst field to indicate the size of the array. .NET Framework ByValTStr types behave like C-style, fixed-size strings inside a structure (for example, char s[5]). The behavior in managed code differs from the Microsoft Visual Basic 6.0 behavior, which is not null terminated (for example, MyString As String * 5). |
![]() | Currency | Used on a System.Decimal to marshal the decimal value as a COM currency type instead of as a Decimal. |
![]() | CustomMarshaler | Specifies the custom marshaler class when used with MarshalAsAttribute.MarshalType or MarshalAsAttribute.MarshalTypeRef. The MarshalAsAttribute.MarshalCookie field can be used to pass additional information to the custom marshaler. You can use this member on any reference type. |
![]() | Error | This native type associated with an I4 or a U4 causes the parameter to be exported as a HRESULT in the exported type library. |
![]() | FunctionPtr | An integer that can be used as a C-style function pointer. You can use this member on a Delegate data type or a type that inherits from a Delegate. |
![]() | I1 | A 1-byte signed integer. You can use this member to transform a Boolean value into a 1-byte, C-style bool (true = 1, false = 0). |
![]() | I2 | A 2-byte signed integer. |
![]() | I4 | A 4-byte signed integer. |
![]() | I8 | An 8-byte signed integer. |
![]() | IDispatch | A COM IDispatch pointer (Object in Microsoft Visual Basic 6.0). |
![]() | Interface | A COM interface pointer. The Guid of the interface is obtained from the class metadata. Use this member to specify the exact interface type or the default interface type if you apply it to a class. This member produces UnmanagedType.IUnknown behavior when you apply it to the Object data type. |
![]() | IUnknown | A COM IUnknown pointer. You can use this member on the Object data type. |
![]() | LPArray | A pointer to the first element of a C-style array. When marshaling from managed to unmanaged, the length of the array is determined by the length of the managed array. When marshaling from unmanaged to managed, the length of the array is determined from the MarshalAsAttribute.SizeConst and the MarshalAsAttribute.SizeParamIndex fields, optionally followed by the unmanaged type of the elements within the array when it is necessary to differentiate among string types. |
![]() | LPStr | A single byte, null-terminated ANSI character string. You can use this member on the System.String or System.Text.StringBuilder data types |
![]() | LPStruct | A pointer to a C-style structure that you use to marshal managed formatted classes. Valid for platform invoke methods only. |
![]() | LPTStr | A platform-dependent character string: ANSI on Windows 98 and Unicode on Windows NT and Windows XP. This value is only supported for platform invoke, and not COM interop, because exporting a string of type LPTStr is not supported. |
![]() | LPWStr | A 2-byte, null-terminated Unicode character string. Note that you cannot use the LPWStr value with an unmanaged string unless the string was created using the unmanaged CoTaskMemAlloc function. |
![]() | R4 | A 4-byte floating point number. |
![]() | R8 | An 8-byte floating point number. |
![]() | SafeArray | A SafeArray is a self-describing array that carries the type, rank, and bounds of the associated array data. You can use this member with the MarshalAsAttribute.SafeArraySubType field to override the default element type. |
![]() | Struct | A VARIANT, which is used to marshal managed formatted classes and value types. |
![]() | SysInt | A platform-dependent, signed integer. 4-bytes on 32 bit Windows, 8-bytes on 64 bit Windows. |
![]() | SysUInt | A platform-dependent, unsigned integer. 4-bytes on 32 bit Windows, 8-bytes on 64 bit Windows. |
![]() | TBStr | A length-prefixed, platform-dependent char string. ANSI on Windows 98, Unicode on Windows NT. You rarely use this BSTR-like member. |
![]() | U1 | A 1-byte unsigned integer. |
![]() | U2 | A 2-byte unsigned integer. |
![]() | U4 | A 4-byte unsigned integer. |
![]() | U8 | An 8-byte unsigned integer. |
![]() | VariantBool | A 2-byte, OLE-defined VARIANT_BOOL type (true = -1, false = 0). |
![]() | VBByRefStr | Allows Visual Basic 2005 to change a string in unmanaged code, and have the results reflected in managed code. This value is only supported for platform invoke. |
Use the UnmanagedType enumeration with the System.Runtime.InteropServices.MarshalAsAttribute to specify how types are marshaled during interoperation with unmanaged code. You can use this enumeration to marshal code using simple value types (I1, I2, I4, I8, R4, R8, U2, U4, and U8), unmanaged types that are unavailable in the .NET Framework, and various miscellaneous types.
For more information, see Interoperating with Unmanaged Code.
The following code fragment demonstrates how to declare in managed source code an unmanaged interface implemented by a COM component. The System.Runtime.InteropServices.ComImportAttribute prevents the IMyStorage interface from being exported back for use by COM. (COM clients should use the existing COM component directly.) In this example, MarshalAsAttribute specifies serveral UnmanagedType members, which represent the types used by the original COM interface.
Imports System Imports System.Runtime.InteropServices Module MyModule ' If you do not have a type library for an interface ' you can redeclare it using ComImportAttribute. ' This is how the interface would look in an idl file. '[ 'object, 'uuid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26"), 'dual, helpstring("IMyStorage Interface"), 'pointer_default(unique) '] 'interface IMyStorage : IDispatch '{ ' [id(1)] ' HRESULT GetItem([in] BSTR bstrName, [out, retval] IDispatch ** ppItem); ' [id(2)] ' HRESULT GetItems([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT)* pItems); ' [id(3)] ' HRESULT GetItemDescriptions([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT) ** ppItems); ' [id(4), propget] ' HRESULT get_IsEmpty([out, retval] BOOL * pfEmpty); '}; ' This is the managed declaration. <ComImport(), Guid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26")> _ Public Interface IMyStorage <DispId(1)> _ Function GetItem(<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByVal bstrName As String) _ As <MarshalAs(UnmanagedType.Interface)> Object <DispId(2)> _ Function GetItems(<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByVal bstrLocation As String, _ <OutAttribute(), MarshalAs(UnmanagedType.SafeArray)> ByVal Items() As Object) <DispId(3)> _ Function GetItemDescriptions(<InAttribute()> ByVal bstrLocation As String, _ <InAttribute(), OutAttribute(), MarshalAs(UnmanagedType.SafeArray)> ByRef varDescriptions() As Object) <DispId(4)> _ ReadOnly Property IsEmpty(<MarshalAs(UnmanagedType.VariantBool)> ByVal bEmpty As Boolean) End Interface End Module
import System.*;
import System.Runtime.InteropServices.*;
// If you do not have a type library for an interface
// you can redeclare it using ComImportAttribute.
// This is how the interface would look in an idl file.
// [
// object,
// uuid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26"),
// dual, helpstring("IMyStorage Interface"),
// pointer_default(unique)
// ]
// interface IMyStorage : IDispatch
// {
// [id(1)]
// HRESULT GetItem([in] BSTR bstrName, [out, retval] IDispatch ** ppItem);
// [id(2)]
// HRESULT GetItems([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT)* pItems);
// [id(3)]
// HRESULT GetItemDescriptions([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT) ** ppItems);
// [id(4), propget]
// HRESULT get_IsEmpty([out, retval] BOOL * pfEmpty);
// };
// This is the managed declaration.
/** @attribute ComImport()
*/
/** @attribute Guid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26")
*/
public interface IMyStorage
{
/** @attribute DispId(1)
*/
Object GetItem(
/** @attribute In()
@attribute MarshalAs(UnmanagedType.BStr)
*/String bstrName);
/** @attribute DispId(2)
*/
void GetItems(
/** @attribute In()
@attribute MarshalAs(UnmanagedType.BStr)
*/String bstrLocation,
/** @attribute Out()
@attribute MarshalAs(UnmanagedType.SafeArray,
SafeArraySubType = VarEnum.VT_VARIANT)
*/Object Items[]);
/** @attribute DispId(3)
*/
void GetItemDescriptions(
/** @attribute In()
*/String bstrLocation,
/** @attribute In()
@attribute Out()
@attribute MarshalAs(UnmanagedType.SafeArray)
*/Object varDescriptions[]);
/** @attribute DispId(4)
*/
/** @return MarshalAs(UnmanagedType.VariantBool)
*/
boolean get_IsEmpty();
} //IMyStorage
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.