TStream.Seek
Sets the current position in the stream
Declaration
Source position: classesh.inc line 965
public
function Seek(Offset: LongInt; Origin: Word) : LongInt; Virtual
; Overload;
function Seek(const Offset: Int64; Origin: TSeekOrigin) : Int64
; Virtual; Overload;
Description
Seek sets the position of the stream to Offset bytes from Origin. There is a 32-bit variant of this function and a 64-bit variant. The difference can be made by choosing the correct Offset parameter: the integer-typed parameter selects the 32-bit variant, the parameter of type TSeekOrigin selects the 64-bit variant of the function.
The Origin parameter for the 32-bit version can have one of the following values:
| Constant | Meaning | | soFromBeginning | Set the position relative to the start of the stream. | | soFromCurrent | Set the position relative to the current position in the stream. | | soFromEnd | Set the position relative to the end of the stream. |
These values are defined in the SysUtils unit.
The Origin parameter for the 64-bit version has one of the following values:
| Value | Meaning | | soBeginning | Offset is interpreted relative to the start of the stream. | | soCurrent | Offset is interpreted relative to the current position in the stream. | | soEnd | Offset is interpreted relative to the end of the stream. |
Offset should be negative when the origin is SoFromEnd (soEnd). It should be positive for soFromBeginning and can have both signs for soFromCurrent
This is an abstract method, which must be overridden by descendant classes. They may choose not to implement this method for all values of Origin and Offset.
Remark
Internally, all calls are re-routed to the 64-bit version of the call. When creating a descendant of TStream, the 64-bit version of the call should be overridden. !!!
Errors
An exception may be raised if this method is called with an invalid pair of Offset,Origin values. e.g. a negative offset for soFromBeginning (or soBeginning).
See also
| Name | Description |
|---|---|
| TStream.Position | The current position in the stream. |