/// <summary>Extracts an icon image from the specified location.</summary>
/// <param name="exIcon">The <see cref="IExtractIconA"/> instance.</param>
/// <param name="pszFile">A pointer to a null-terminated string that specifies the icon location.</param>
/// <param name="nIconIndex">The index of the icon in the file pointed to by pszFile.</param>
/// <param name="nIconSizeLarge">
/// The desired size of the large icon, in pixels. The size specified can be the width or height. The width of an icon always equals
/// its height.
/// </param>
/// <param name="phiconLarge">A pointer to an HICON value that receives the handle to the large icon. This parameter may be NULL.</param>
/// <param name="nIconSizeSmall">
/// The desired size of the small icon, in pixels. The size specified can be the width or height. The width of an icon always equals
/// its height.
/// </param>
/// <param name="phiconSmall">A pointer to an HICON value that receives the handle to the small icon. This parameter may be NULL.</param>
/// <returns>Returns S_OK if the function extracted the icon, or S_FALSE if the calling application should extract the icon.</returns>
public static HRESULT Extract(this IExtractIconA exIcon, string pszFile, uint nIconIndex, ushort nIconSizeLarge, out SafeHICON phiconLarge, ushort nIconSizeSmall, out SafeHICON phiconSmall)
{
if (exIcon is null)
{
throw new ArgumentNullException(nameof(exIcon));
}
var sz = Macros.MAKELONG(nIconSizeLarge, nIconSizeSmall);
unsafe
{
HICON h1 = default, h2 = default;
/// <summary>Extracts an icon image from the specified location.</summary>
/// <param name="exIcon">The <see cref="IExtractIconA"/> instance.</param>
/// <param name="pszFile">A pointer to a null-terminated string that specifies the icon location.</param>
/// <param name="nIconIndex">The index of the icon in the file pointed to by pszFile.</param>
/// <param name="nIconSize">
/// The desired size of the icon, in pixels. The size specified can be the width or height. The width of an icon always equals
/// its height.
/// </param>
/// <param name="phicon">A pointer to an HICON value that receives the handle to the icon. This parameter may be NULL.</param>
/// <returns>Returns S_OK if the function extracted the icon, or S_FALSE if the calling application should extract the icon.</returns>
public static HRESULT Extract(this IExtractIconA exIcon, string pszFile, uint nIconIndex, ushort nIconSize, out SafeHICON phicon)
{
if (exIcon is null)
{
throw new ArgumentNullException(nameof(exIcon));
}
var sz = nIconSize > 16 ? Macros.MAKELONG(nIconSize, 0) : Macros.MAKELONG(0, nIconSize);
unsafe
{
HICON h1 = default;
var hr = nIconSize > 16 ? exIcon.Extract(pszFile, nIconIndex, &h1, null, sz) : exIcon.Extract(pszFile, nIconIndex, null, &h1, sz);
phicon = h1 == default ? null : new SafeHICON((IntPtr)h1);
return(hr);
}
}
/// <summary>Gets the icon for the item using the specified characteristics.</summary>
/// <param name="iei">The IExtractIconA from which to retrieve the icon.</param>
/// <param name="imgSz">The width, in pixels, of the icon.</param>
/// <param name="hico">The resulting icon handle, on success, or <c>null</c> on failure.</param>
/// <returns>The result of function.</returns>
public static HRESULT LoadIconFromExtractIcon(IExtractIconA iei, ref uint imgSz, out SafeHICON hico)
{
var szIconFile = new StringBuilder(Kernel32.MAX_PATH);
var hr = iei.GetIconLocation(GetIconLocationFlags.GIL_FORSHELL, szIconFile, szIconFile.Capacity, out var iIdx, out _);
if (hr.Succeeded)
{
if (szIconFile.ToString() != "*")
{
hr = iei.Extract(szIconFile.ToString(), (uint)iIdx, (ushort)imgSz, out hico);
}
else
{
hr = LoadIconFromSystemImageList(iIdx, ref imgSz, out hico);
}
}
else
{
hico = null;
}
return(hr);
}
