Variant Structure

Variant Structure

Represents an object that can be interpreted as more than one type.

This API is not CLS-compliant. The CLS-compliant alternative is [None].

Namespace:  Microsoft.VisualStudio.Package
Assemblies:   Microsoft.VisualStudio.Package.LanguageService.9.0 (in Microsoft.VisualStudio.Package.LanguageService.9.0.dll)
  Microsoft.VisualStudio.Package.LanguageService.11.0 (in Microsoft.VisualStudio.Package.LanguageService.11.0.dll)
  Microsoft.VisualStudio.Package.LanguageService (in Microsoft.VisualStudio.Package.LanguageService.dll)
  Microsoft.VisualStudio.Package.LanguageService.10.0 (in Microsoft.VisualStudio.Package.LanguageService.10.0.dll)

[CLSCompliantAttribute(false)]
public struct Variant

The Variant type exposes the following members.

  NameDescription
Public propertyValueDetermines the value of this Variant object.
Public propertyVtDetermines the type of the Variant object.
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  NameDescription
Public methodEqualsIndicates whether this instance and a specified object are equal. (Inherited from ValueType.)
Public methodGetHashCodeReturns the hash code for this instance. (Inherited from ValueType.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodToCharInterprets the Variant object's value as a Unicode character if the variant type is VT_UI2.
Public methodToStringReturns the fully qualified type name of this instance. (Inherited from ValueType.)
Public methodStatic memberToVariantConverts the given variant object to a Variant class object.
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This version of the variant structure is specific to the managed package framework (MPF) language service classes and is designed to primarily convert a variant to a character. More specifically, if the variant has the type VT_UI2, the variant object is converted to a character.

This structure is actually used in only one place in the MPF language service classes, the HandlePreExec method of the ViewFilter class. This structure is used to convert the incoming variant to a character if the type of command is TYPECHAR.

Notes to Implementers

This is a limited structure and there is nothing to override.

Notes to Callers

This is a structure and can be treated as a variable type. It has limited functionality, mainly designed to convert from a variant object to a character.

This example shows how the MPF ViewFilter class uses this Variant structure to convert an incoming variant object to a character.

namespace Microsoft.VisualStudio.Package
{
    [CLSCompliant(false)]
    [System.Runtime.InteropServices.ComVisible(true)]
    public class ViewFilter 
        : IVsTextViewFilter
        , IVsTextViewEvents
        , IOleCommandTarget
        , IDisposable
    {
        public virtual void HandlePostExec(ref Guid guidCmdGroup,
                                           uint nCmdId,
                                           uint nCmdexecopt,
                                           IntPtr pvaIn,
                                           IntPtr pvaOut)
        { 

            if (guidCmdGroup == VsMenus.guidStandardCommandSet2K) {
                VsCommands2K cmd = (VsCommands2K)nCmdId;
                char ch = '\0';
                if (cmd == VsCommands2K.TYPECHAR && pvaIn != IntPtr.Zero) {
                    Variant v = Variant.ToVariant(pvaIn);
                    ch = v.ToChar();

                    // Do something with the character

                }
            }
        }
    }
}

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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