IMcObjectValue Property

Property Value

Type: Object

This property is the default property of the McObject interface. The Value property can only be assigned to for objects which are not flagged as "Read-Only". On assignment, any standard notify clients get sent a IMcObjStandardNotify::ValueChanged call after the value(s) have been changed. The Value property of an mcobjTypeFlagAlias type object (see McObjects.Add and Type for a discussion of Alias type objects), reflects the Value of its ShadowMcObject if one is assigned. If no ShadowMcObject is assigned, then an Alias-type object will just return an error Variant (VT_ERROR) as a value. Attempts to assign the Value property of an alias type object with no ShadowMcObject results in a FAILED error return. When the Value property is assigned, the mcobjUserFlagAlwaysVector UserFlags bit is automatically set or cleared depending on whether the source Variant is an Array (set) or a scalar value (cleared). When set, the mcobjUserFlagAlwaysVector causes scalar object values to be exposed as an array. After assigning to Value you can subsequently assign a different state to this bit in the UserFlags property to override the default behavior. The mcobjUserFlagAlwaysVector does not affect how objects of type mcobjTypeCHAR (strings) are exposed. Value's assigned from an Array of strings (even a length-1 array) will be returned as an Array of strings. If the mcobjUserFlagNotifyOnGetValue UserFlag bit is set, then a SpecialNotify with an lNotifyCode of mcobjSNCode_BeforeGetValue is sent to standard notify clients (IMcObjStandardNotify interfaces; see FireStandardNotifyToAllSinks) before the Value property is returned. This allows an McObjStandardNotify client interface to set or update the object's Value property only when it is requested. If the sink does process the mcobjSNCode_BeforeGetValue SpecialNotify, then it should return S_FALSE instead of S_OK from the call; this has the effect of aborting the notify for any other sinks and also signals that a ValueChange notify will need to be sent. Should a notify client change the Value property during the mcobjSNCode_BeforeGetValue SpecialNotify but not return S_FALSE, then no ValueChanged notify will be sent, so be sure to follow this rule. If the mcobjUserFlagKeepByRefVariants UserFlags bit is set, then objects of type mcobjTypeVARIANT (where the data is actually stored as a VARIANT) will not copy the referred-to data of VT_BYREF variants on either assignment or access. If clear (the default), then any VT_BYREF is unraveled and the actual data is copied.