public int CreateStreamFromKey(IntPtr fontFileReferenceKey,
uint fontFileReferenceKeySize,
out IDWriteFontFileStreamMirror fontFileStream)
{
uint numberOfCharacters = fontFileReferenceKeySize / 2;
fontFileStream = null;
if ((fontFileReferenceKeySize % 2 != 0) || // The fontFileReferenceKeySize must be divisible by sizeof(WCHAR)
(numberOfCharacters <= 1) || // The fontFileReferenceKey cannot be less than or equal 1 character as it has to contain the NULL character.
(Marshal.ReadInt16(fontFileReferenceKey, ((int)numberOfCharacters - 1) * 2) != '\0')) // The fontFileReferenceKey must end with the NULL character
{
return(unchecked ((int)0x80070057)); // E_INVALIDARG
}
string uriString = Marshal.PtrToStringUni(fontFileReferenceKey);
int hr = 0;
try
{
IFontSource fontSource = _fontSourceFactory.Create(uriString);
FontFileStream customFontFileStream = new FontFileStream(fontSource);
fontFileStream = (IDWriteFontFileStreamMirror)customFontFileStream;
}
catch (System.Exception exception)
{
hr = Marshal.GetHRForException(exception);
}
return(hr);
}
public FontFile CreateFontFile(Uri filePathUri)
{
IDWriteFontFile dwriteFontFile = null;
try {
dwriteFontFile = CreateFontFile(_pFactory, WpfFontFileLoader, filePathUri);
}
catch {
// If DWrite's CreateFontFileReference fails then try opening the file using WPF's logic.
// The failures that WPF returns are more granular than the HRESULTs that DWrite returns
// thus we use WPF's logic to open the file to throw the same exceptions that
// WPF would have thrown before.
IFontSource fontSource = _fontSourceFactory.Create(filePathUri.AbsoluteUri);
fontSource.TestFileOpenable();
throw;
}
return(new FontFile(dwriteFontFile));
}