/// <summary>
/// Renders a page of the PDF document to an image.
/// </summary>
/// <param name="page">Number of the page to render.</param>
/// <param name="width">Width of the rendered image.</param>
/// <param name="height">Height of the rendered image.</param>
/// <param name="dpiX">Horizontal DPI.</param>
/// <param name="dpiY">Vertical DPI.</param>
/// <param name="flags">Flags used to influence the rendering.</param>
/// <returns>The rendered image.</returns>
public Image Render(int page, int width, int height, float dpiX, float dpiY, PdfRenderFlags flags)
{
if (_disposed)
{
throw new ObjectDisposedException(GetType().Name);
}
var bitmap = new Bitmap(width, height, PixelFormat.Format32bppArgb);
bitmap.SetResolution(dpiX, dpiY);
var data = bitmap.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
try
{
var handle = NativePdfiumMethods.FPDFBitmap_CreateEx(width, height, 4, data.Scan0, width * 4);
try
{
uint background = (flags & PdfRenderFlags.Transparent) == 0 ? 0xFFFFFFFF : 0x00FFFFFF;
NativePdfiumMethods.FPDFBitmap_FillRect(handle, 0, 0, width, height, background);
bool success = _file.RenderPDFPageToBitmap(
page,
handle,
(int)dpiX, (int)dpiY,
0, 0, width, height,
this.FlagsToFPDFFlags(flags)
);
if (!success)
{
throw new Win32Exception();
}
}
finally
{
NativePdfiumMethods.FPDFBitmap_Destroy(handle);
}
}
finally
{
bitmap.UnlockBits(data);
}
return(bitmap);
}