`pdfSetEmbeddedFileStrProperty`

Change a string property of an existing attachment.

Exported names	`pdfSetEmbeddedFileStrProperty` (bare = ANSI), `pdfSetEmbeddedFileStrPropertyA`, `pdfSetEmbeddedFileStrPropertyW`

Purpose — Change a string property of an existing attachment.

Description — Index is the 1-based attachment handle. Tag selects the property:

Tag	Property written at serialization
`0`	`/Desc` (description)
`1`	`/AFRelationship` (name — e.g. `Data`, `Source`, `Alternative`; setting it makes the file an associated file)
`2`	`/F` and `/UF` (file name)

Any other tag fails. The W variant is narrowed to 8-bit storage.

int32_t __stdcall pdfSetEmbeddedFileStrPropertyA(PPDF IPDF, int32_t Index, int32_t Tag, const char*    NewValue);
int32_t __stdcall pdfSetEmbeddedFileStrPropertyW(PPDF IPDF, int32_t Index, int32_t Tag, const wchar_t* NewValue);

Return value — 1 on success, 0 on failure (invalid instance handle, index out of range, unknown tag). Integer, not BOOL32.

C# (P/Invoke)

wrappers/dotnet/LumasPdf.cs

public static extern int pdfSetEmbeddedFileStrPropertyW(IntPtr IPDF, int Index, int Tag, IntPtr NewValue);
public static extern int pdfSetEmbeddedFileStrProperty(IntPtr IPDF, int Index, int Tag, IntPtr NewValue);
public static extern int pdfSetEmbeddedFileStrPropertyA(IntPtr IPDF, int Index, int Tag, IntPtr NewValue);

Area

Import & Output APIs