IWICPalette::HasAlpha method (wincodec.h)

Indicates whether the palette contains an entry that is non-opaque (that is, an entry with an alpha that is less than 1).

Syntax

HRESULT HasAlpha(
  [out] BOOL *pfHasAlpha
);

Parameters

[out] pfHasAlpha

Type: BOOL*

Pointer that receives TRUE if the palette contains a transparent color; otherwise, FALSE.

Return value

Type: HRESULT

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

Various image formats support alpha in different ways. PNG has full alpha support by supporting partially transparent palette entries. GIF stores colors as 24bpp, without alpha, but allows one palette entry to be specified as fully transparent. If a palette has multiple fully transparent entries (0x00RRGGBB), GIF will use the last one as its transparent index.

Requirements

Requirement	Value
Minimum supported client	Windows XP with SP2, Windows Vista [desktop apps | UWP apps]
Minimum supported server	Windows Server 2008 [desktop apps | UWP apps]
Target Platform	Windows
Header	wincodec.h
Library	Windowscodecs.lib
DLL	Windowscodecs.dll