System.Classes.TReader.ReadListBegin
Delphi
procedure ReadListBegin; inline;
C++
void __fastcall ReadListBegin();
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
procedure function |
public | System.Classes.pas System.Classes.hpp |
System.Classes | TReader |
Description
Reads a start-of-list value-type indicator from the reader object's stream.
ReadListBegin is used by other methods that iterate through a list of items to ensure that the type about to be read is a list.
ReadListBegin checks whether the next data item at the current reader Position in the stream is a start-of list vaList value-type indicator as written by the WriteListBegin method.
ReadListBegin calls ReadValue to check whether the value-type indicator is vaList, and then ReadListBegin succeeds and advances the stream position after the value-type indicator.
If ReadValue retrieves other than vaList but correct value-type indicator, then ReadListBegin skips the number of bytes specified by the obtained value-type indicator and raises an EReadError exception.
A call to ReadListBegin is generally followed by a reading loop that terminates when the EndOfList method returns True, indicating that an end-of-list marker is next on the stream, at which point a call to ReadListEnd is required.