public static extern void wkhtmltoimage_set_warning_callback(IntPtr converter, [MarshalAs(UnmanagedType.FunctionPtr)] wkhtmltoimage_str_callback cb);
private byte[] _Convert(string inputHtml) { var converter = IntPtr.Zero; var inputHtmlUtf8Ptr = IntPtr.Zero; var errorCb = new wkhtmltoimage_str_callback(OnError); var warnCb = new wkhtmltoimage_str_callback(OnWarning); var phaseCb = new wkhtmltoimage_void_callback(OnPhaseChanged); var progressCb = new wkhtmltoimage_int_callback(OnProgressChanged); var finishCb = new wkhtmltoimage_bool_callback(OnFinished); try { var gSettings = _BuildGlobalSettings(); //var oSettings = _BuildObjectsettings(); inputHtmlUtf8Ptr = Marshaller.StringToUtf8Ptr(inputHtml); converter = _BuildConverter(gSettings, inputHtmlUtf8Ptr); _errorString = new StringBuilder(); wkhtmltoimage_set_error_callback(converter, errorCb); wkhtmltoimage_set_warning_callback(converter, warnCb); wkhtmltoimage_set_phase_changed_callback(converter, phaseCb); wkhtmltoimage_set_progress_changed_callback(converter, progressCb); wkhtmltoimage_set_finished_callback(converter, finishCb); OnBegin(wkhtmltoimage_phase_count(converter)); if (!wkhtmltoimage_convert(converter)) { var msg = string.Format("HtmlToPdf conversion failed: {0}", _errorString.ToString()); throw new ApplicationException(msg); } if (!string.IsNullOrEmpty(GlobalSettings.Out)) return null; _Log.LogDebug("CONVERSION DONE.. getting output."); // Get output from internal buffer.. IntPtr tmp = IntPtr.Zero; var len = wkhtmltoimage_get_output(converter, out tmp); var output = new byte[len]; Marshal.Copy(tmp, output, 0, output.Length); return output; } finally { if (converter != IntPtr.Zero) { wkhtmltoimage_set_error_callback(converter, null); wkhtmltoimage_set_warning_callback(converter, null); wkhtmltoimage_set_phase_changed_callback(converter, null); wkhtmltoimage_set_progress_changed_callback(converter, null); wkhtmltoimage_set_finished_callback(converter, null); wkhtmltoimage_destroy_converter(converter); } if (inputHtmlUtf8Ptr != IntPtr.Zero) { Marshaller.FreeUtf8Ptr(inputHtmlUtf8Ptr); } } }