ErrorWrapper Class
Definition
Important
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Caution
ErrorWrapper and support for marshalling to the VARIANT type may be unavailable in future releases.
Wraps objects the marshaler should marshal as a VT_ERROR
.
public ref class ErrorWrapper sealed
[System.Obsolete("ErrorWrapper and support for marshalling to the VARIANT type may be unavailable in future releases.")]
public sealed class ErrorWrapper
public sealed class ErrorWrapper
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public sealed class ErrorWrapper
[<System.Obsolete("ErrorWrapper and support for marshalling to the VARIANT type may be unavailable in future releases.")>]
type ErrorWrapper = class
type ErrorWrapper = class
[<System.Runtime.InteropServices.ComVisible(true)>]
[<System.Serializable>]
type ErrorWrapper = class
Public NotInheritable Class ErrorWrapper
- Inheritance
-
ErrorWrapper
- Attributes
Examples
The following code example first demonstrates a lone Int32 object marshaled back from COM as an Int32 object. It then demonstrates an Int32 array marshaled back from COM as a UInt32 array.
// Scenario 1:
// Pass a single value.
Int32 x = 3;
Object o = new ErrorWrapper(x);
// Pass 'o' to COM.
// On the return trip, 'o' has been unwrapped and is still an Int32 object.
Int32 y = (Int32)o;
Scenario 2:
// Pass an array of values.
Int32[] arr = new Int32[3];
Object o = new ErrorWrapper(arr);
// Pass 'o' to COM.
// On the return trip, 'o' has been unwrapped and is now a UInt32[] array.
UInt32[ ] arr2 = (UInt32[])o;
Remarks
By default, Object type arguments are marshaled as a VARIANT
type, where the object type determines the VARTYPE
value of the VARIANT
.
The ErrorWrapper type must to be passed as an Object type to be marshaled as a VARIANT
of type VT_ERROR
, otherwise the ErrorWrapper type is marshaled as an integer.
The following table illustrates marshaling in a managed call to a native function, using platform invoke.
Managed signature parameter | pArr value | Marshaled as |
---|---|---|
ErrorWrapper[] pArr | ErrorWrapper[10] of ErrorWrapper(77) | Int[10] |
Object[] pArr | ErrorWrapper[10] of ErrorWrapper(77) | VARIANT[10] of VT_ERROR |
Object[] pArr | Object[10] of ErrorWrapper(77) | VARIANT[10] of VT_ERROR |
The following table illustrates marshaling data in a managed call to a native function, using COM runtime callable wrappers (RCW).
Managed signature parameter | pArr value | Marshaled as |
---|---|---|
ErrorWrapper[] pArr | ErrorWrapper[10] of ErrorWrapper(77) | Int[10] |
Object[] pArr | ErrorWrapper[10] of ErrorWrapper(77) | SafeArrayTypeMismatch exception |
Object[] pArr | Object[10] of ErrorWrapper(77) | SAFEARRAY(VARIANT) |
Note that ErrorWrapper objects are not marshaled as type VT_ERROR
after they are passed back from COM. A single value is marshaled back from COM as type VT_I4
, while arrays are marshaled back from COM as type VT_UI4
.
For more information on VT_ERROR
, please see the existing documentation for VARENUM::VT_ERROR
in the MSDN library.
Constructors
ErrorWrapper(Exception) |
Initializes a new instance of the ErrorWrapper class with the HRESULT that corresponds to the exception supplied. |
ErrorWrapper(Int32) |
Initializes a new instance of the ErrorWrapper class with the HRESULT of the error. |
ErrorWrapper(Object) |
Initializes a new instance of the ErrorWrapper class with an object containing the HRESULT of the error. |
Properties
ErrorCode |
Gets the error code of the wrapper. |
Methods
Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
GetType() |
Gets the Type of the current instance. (Inherited from Object) |
MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
ToString() |
Returns a string that represents the current object. (Inherited from Object) |