Stream Object (ADO)

Microsoft ActiveX Data Objects (ADO)

Stream Object

               

Represents a stream of binary data or text.

Remarks

In tree-structured hierarchies such as a file system or an e-mail system, a Record may have a default binary stream of bits associated with it that contains the contents of the file or the e-mail. A Stream object can be used to manipulate fields or records containing these streams of data. A Stream object can be obtained in these ways:

  • From a URL pointing to an object (typically a file) containing binary or text data. This object can be a simple document, a Record object representing a structured document, or a folder.

  • By opening the default Stream object associated with a Record object. You can obtain the default stream associated with a Record object when the Record is opened, to eliminate a round-trip just to open the stream.

  • By instantiating a Stream object. These Stream objects can be used to store data for the purposes of your application. Unlike a Stream associated with a URL, or the default Stream of a Record, an instantiated Stream has no association with an underlying source by default.

With the methods and properties of a Stream object, you can do the following:

  • Open a Stream object from a Record or URL with the Open method.

  • Close a Stream with the Close method.

  • Input bytes or text to a Stream with the Write and WriteText methods.

  • Read bytes from the Stream with the Read and ReadText methods.

  • Write any Stream data still in the ADO buffer to the underlying object with the Flush method.

  • Copy the contents of a Stream to another Stream with the CopyTo method.

  • Control how lines are read from the source file with the SkipLine method and the LineSeparator property.

  • Determine the end of stream position with the EOS property and SetEOS method.

  • Save and restore data in files with the SaveToFile and LoadFromFile methods.

  • Specify the character set used for storing the Stream with the Charset property.

  • Halt an asynchronous Stream operation with the Cancel method.

  • Determine the number of bytes in a Stream with the Size property.

  • Control the current position within a Stream with the Position property.

  • Determine the type of data in a Stream with the Type property.

  • Determine the current state of the Stream (closed, open, or executing) with the State property.

  • Specify the access mode for the Stream with the Mode property.