GetLastError

Document parts, variable data, document editing

Description

ReadRangeTCallbackByteRangeSource

TCallbackByteRangeSource call on a TPDFlib.LoadFromRangeSource The internal IPLByteRangeSource class adapts the read and availability callbacks supplied to IPLByteRangeAvailabilitySource into a reference-counted

Syntax

Function TCallbackByteRangeSource.GetLastError: AnsiString;

Remarks

ReadRange clears the message at the start of every call, so the value reflects only the most recent attempt

A rejected range request records a fixed invalid-request message, and an exception raised by the read callback records the exception message

A callback result that is clamped to the requested count is not treated as an error and leaves the message empty

Return values

Empty string. The last ReadRange call completed without a recorded failure
Message text. The invalid-request message or the callback exception message recorded by the last ReadRange call

See also

ReadRange, IsRangeAvailable, GetRangeSupported, GetTotalSize, LoadFromRangeSource