ArcObjects Library Reference (System)

MemoryBlobStream CoClass

Memory blob stream object.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Description

When implementing your own objects, you will sometimes need to provide support for persistence. For example, with a custom feature renderer, persistence enables its settings to be written to an MXD file so that when ArcMap is restarted, the layer having custom rendering will be drawn in the same way as previously drawn. The COM concept of streams provides a way of reading and writing data to the persisted storage.

A memory blob stream provides storage for binary data in memory.

Supported Platforms

Windows, Solaris, Linux

Extended Error Information

Use the ISupportErrorInfo method InterfaceSupportsErrorInfo to determine if the object supports extended error information. If the object supports extended error info, VC++ developers should use the OLE/COM IErrorInfo interface to access the ErrorInfo object. Visual Basic developers should use the global error object Err to retrieve this extended error information.

Interfaces

Interfaces	Description
IBlobStream	Provides access to members that control a Blob Stream.
IDocumentVersion	Provides access to members that control the document version.
IMemoryBlobStream	Provides access to members that control the Blob Stream.
IMemoryBlobStream2	Provides access to members that control the Blob Stream.
IMemoryBlobStreamVariant	Provides access to methods for importing and exporting variants to and from a MemoryBlobStream.
ISupportErrorInfo (esriSystem)	Indicates whether a specific interface can return Automation error objects.

Remarks

MemoryBlobStreams are particularly useful for writing arbitrary data to databases. When writing objects to the database, you should cocreate an ObjectStream and use that in conjunction with your MemoryBlobStream.