`pdfSetTextUnderlineDistance`

Set the underline's vertical offset below the text baseline.

Category	Text decoration

Purpose — Set the underline's vertical offset below the text baseline.

Declarations

int32_t __stdcall pdfSetTextUnderlineDistance(PPDF IPDF, double UnderlineDistance);

Delphi

function pdfSetTextUnderlineDistance(const IPDF: PPDF; UnderlineDistance: Double): Integer; stdcall; external 'LumasPdf.dll';

Parameters

Parameter	Type	Description
`IPDF`	`PPDF`	Instance handle.
`UnderlineDistance`	`Double`	Points below baseline. `0` (the sentinel, not a literal zero-offset) falls back to `fontSize × 0.10` at draw time.

Return value — 1 on a valid handle; 0 on an invalid handle.

Remarks — Because 0 is treated as "unset" rather than "flush with the baseline," you cannot position the underline exactly on the baseline through this call — the closest you can get is a very small nonzero value.

See also — pdfSetTextUnderlineWidth

C# (P/Invoke)

wrappers/dotnet/LumasPdf.cs

public static extern int pdfSetTextUnderlineDistance(IntPtr IPDF, double UnderlineDistance);

Area

Text