Printing APIs<\/h2>\n\n\n\n
The WebView2 control is constantly evolving, with new capabilities added with each new release. However, this actually poses a problem with the API. Since existing COM interfaces should be stable, every new additions are made to a new interface. At the point of writing this article, there is The printing APIs are the following:<\/p>\n\n\n\n In this article, we will discuss We’ll modify the existing demo application with new options on the toolbar, as shown in the following image:<\/p>\n\n\n\n The first option that we’ll address is displaying the print dialog. For this purpose, we’ll use the ICoreWebView2_16::ShowPrintUI()<\/a> method. It has a single parameter, an enumeration that specifies the kind of dialog to display: system’s default or browser specific. Using this method is straight forward:<\/p>\n\n\n\n Here is the result of running with either option:<\/p>\n\n\n\n Printing to a PDF document is a very popular option nowadays. It’s no surprise it was the first printing feature supported by the WebView2 control. For this, we will use the ICoreWebView2_7::PrintToPdf()<\/a> method. This method has two parameters: a pointer to a printer settings object and a completion handler (that is called when the operation has completed). If the first argument is set to null, the default printer settings are being used.<\/p>\n\n\n\n Here is how this method can be used:<\/p>\n\n\n\n There are several things happening here:<\/p>\n\n\n\n The following snippet shows the code in the main frame that invokes the PDF printing. Here you can notice the check of the print-in-progress flag:<\/p>\n\n\n\n In the next images, you can see the PDFs created from the web page, with portrait and landscape orientation:<\/p>\n\n\n\n You can download the demo application and try it here: ICoreWebView2<\/code>, ICoreWebView2_2<\/code>, ICoreWebView2_3<\/code>, up to ICoreWebView2_17<\/code>. There are also ICoreWebView2Environment<\/code>, ICoreWebView2Environment2<\/code> and up to ICoreWebView2Environment12<\/code>, ICoreWebView2EnvironmentOptions<\/code> and up to ICoreWebView2EnvironmentOptions5<\/code>, ICoreWebView2Settings<\/code> and up to ICoreWebView2Settings7<\/code>, and so on and so forth. If you ask me, the API is becoming cumbersome, but that’s the way it is and we have to live with it.<\/p>\n\n\n\nPrintToPdf<\/code> (prints the current web page as a PDF document)<\/li>Print<\/code> (to print the current page to the specified printer, with the specified settings), PrintToPdfStream<\/code> (prints the current web page as PDF to a stream), and ShowPrintUI<\/code> (opens a print dialog).<\/li><\/ul>\n\n\n\nPrintToPdf()<\/code> and ShowPrintUI()<\/code>.<\/p>\n\n\n\n![\"\"](\"https:\/\/mariusbancila.ro\/blog\/wp-content\/uploads\/2023\/04\/toolbar.png\" "\\"\\"")
<\/a><\/figure><\/div>\n\n\n\nDisplaying a printing dialog<\/h2>\n\n\n\n
void CWebBrowser::ShowPrintUI(bool const systemDialog)\n{\n if (m_pImpl->m_webView != nullptr)\n {\n CHECK_FAILURE(m_pImpl->m_webView2_16->ShowPrintUI(systemDialog ? COREWEBVIEW2_PRINT_DIALOG_KIND_SYSTEM : \n COREWEBVIEW2_PRINT_DIALOG_KIND_BROWSER));\n } \n}<\/pre>\n\n\n\n![\"\"](\"https:\/\/mariusbancila.ro\/blog\/wp-content\/uploads\/2023\/04\/printersystem.png\")
<\/a>![\"\"](\"https:\/\/mariusbancila.ro\/blog\/wp-content\/uploads\/2023\/04\/printerbrowser.png\")
<\/a>Printing to PDF<\/h2>\n\n\n\n
void CWebBrowser::PrintToPDF(bool const landscape, std::function<void(bool, CString)> callback)\n{\n WCHAR defaultName[MAX_PATH] = L\"default.pdf\";\n\n OPENFILENAME openFileName = {};\n openFileName.lStructSize = sizeof(openFileName);\n openFileName.hwndOwner = nullptr;\n openFileName.hInstance = nullptr;\n openFileName.lpstrFile = defaultName;\n openFileName.lpstrFilter = L\"PDF File\\0*.pdf\\0\";\n openFileName.nMaxFile = MAX_PATH;\n openFileName.Flags = OFN_OVERWRITEPROMPT;\n\n if (::GetSaveFileName(&openFileName))\n {\n wil::com_ptr<ICoreWebView2PrintSettings> printSettings = nullptr;\n wil::com_ptr<ICoreWebView2Environment6> webviewEnvironment6;\n CHECK_FAILURE(m_pImpl->m_webViewEnvironment->QueryInterface(IID_PPV_ARGS(&webviewEnvironment6)));\n\n if (webviewEnvironment6)\n {\n CHECK_FAILURE(webviewEnvironment6->CreatePrintSettings(&printSettings));\n CHECK_FAILURE(printSettings->put_Orientation(landscape ? COREWEBVIEW2_PRINT_ORIENTATION_LANDSCAPE : \n COREWEBVIEW2_PRINT_ORIENTATION_PORTRAIT));\n }\n\n wil::com_ptr<ICoreWebView2_7> webview2_7;\n CHECK_FAILURE(m_pImpl->m_webView->QueryInterface(IID_PPV_ARGS(&webview2_7)));\n if (webview2_7)\n {\n m_printToPdfInProgress = true;\n\n CHECK_FAILURE(webview2_7->PrintToPdf(\n openFileName.lpstrFile, \n printSettings.get(),\n Callback<ICoreWebView2PrintToPdfCompletedHandler>(\n [this, callback, &openFileName](HRESULT errorCode, BOOL isSuccessful) -> HRESULT {\n CHECK_FAILURE(errorCode);\n\n m_printToPdfInProgress = false;\n\n callback(isSuccessful, openFileName.lpstrFile);\n\n return S_OK;\n })\n .Get()));\n }\n }\n}\n<\/pre>\n\n\n\nICoreWebView2_7<\/code> interface is retrieved so that we can invoke the PrintToPdf()<\/code> method.<\/li>m_printToPdfInProgress<\/code> is used to indicate that a printing operation is in progress. This is then used elsewhere in the application to ensure a second operation is not started until the current one completes. This is because a single print operation can execute at any given point. If any of the available print methods (listed in the beginning) are invoked while a print job is in process, the completion handler is invoked immediately with the isSuccessful<\/code> argument set to FALSE<\/code>.<\/li><\/ul>\n\n\n\nvoid CMainFrame::OnButtonPrintToPdf()\n{\n auto view = dynamic_cast<CMfcEdgeDemoView*>(GetActiveView());\n if (view != nullptr)\n {\n if (view->IsPrintToPdfInProgress())\n {\n ::MessageBox(\n nullptr,\n L\"A PDF file is currently printing. Please wait until the operation completes.\",\n L\"Warning\",\n MB_OK|MB_ICONEXCLAMATION);\n\n return;\n }\n\n CButton* check = (CButton*)m_wndDlgBar.GetDlgItem(IDC_CHECK_LANDSCAPE);\n\n view->PrintToPDF(check->GetCheck() == BST_CHECKED, [](bool const isSuccessful, CString path) {\n if (isSuccessful)\n {\n auto result = ::MessageBox(\n nullptr,\n L\"Print to PDF succeeded. Would you like to open the document?\",\n L\"Print to PDF completed\",\n MB_YESNO);\n \n if (result == IDYES)\n {\n ShellExecute(0, 0, path, 0, 0, SW_SHOW);\n }\n }\n else\n {\n ::MessageBox(\n nullptr,\n L\"Print to PDF failed\",\n L\"Print to PDF completed\",\n MB_OK);\n }\n });\n }\n}<\/pre>\n\n\n\n![\"\"](\"https:\/\/mariusbancila.ro\/blog\/wp-content\/uploads\/2023\/04\/pdfportrait-700x604.png\")
<\/a>![\"\"](\"https:\/\/mariusbancila.ro\/blog\/wp-content\/uploads\/2023\/04\/pdflandscape-700x604.png\")
<\/a>Downloads<\/h2>\n\n\n\n