- Import an HTML File into the Rich Text Editor or Export a Document to HTML
- Import HTML Content
- Load an HTML Page
- Method 1
- Method 2
- Specify HTML Text
- Method 1
- Method 2
- Define Import Options
- Convert HTML To Another Format
- Example 1. Convert HTML to PDF
- Example 2. Convert HTML to DOCX
- Import Tips
- Export to HTML
- Save as HTML File
- Return HTML Text
- Define Export Options
- Export Images
- Embed Images
- Specify External Image Location
Import an HTML File into the Rich Text Editor or Export a Document to HTML
The Rich Text Editor allows you to import HTML files and save documents as HTML. When you open an HTML file, the control converts HTML content into its internal document model. Some HTML tags and CSS attributes have no counterparts in Open XML and RTF formats. You can find more information about supported and unsupported HTML tags in the following help topic: HTML Support Limitations. However, we must emphasize that the Rich Text Editor is not an HTML editor/browser. It can display your HTML document differently from your web browser even if all HTML tags were imported into the control’s document model.
Import HTML Content
Load an HTML Page
Method 1
Use the RichEditControl.DocumentSource property to specify a document source for the Rich Text Editor in XAML.
The following example uses DXBinding to call a method that returns a path to a specified HTML document.
" >public class HtmlDataSource < public static string GetDocumentPath(string fileName) < string path = System.IO.Path.Combine(System.Environment.CurrentDirectory, fileName); if (System.IO.File.Exists(path)) return path; return ""; >>
" >Public Class HtmlDataSource Public Shared Function GetDocumentPath(ByVal fileName As String) As String Dim path As String = System.IO.Path.Combine(Environment.CurrentDirectory, fileName) If System.IO.File.Exists(path) Then Return path End If Return "" End Function End Class
Method 2
Call the RichEditControl.LoadDocument or RichEditControl.Document.LoadDocument method to import an HTML page into the Rich Text Editor.
" >richEditControl1.LoadDocument("HtmlDocument.html", DocumentFormat.Html);
" >richEditControl1.LoadDocument("HtmlDocument.html", DocumentFormat.Html)
The sourceUri parameter of the LoadDocument method allows you to load files associated with an HTML document.
" >richEditControl1.LoadDocument("HtmlDocument.html", DocumentFormat.Html, "HtmlDocument_files");
" >richEditControl1.LoadDocument("HtmlDocument.html", DocumentFormat.Html, "HtmlDocument_files")
Specify HTML Text
Method 1
Bind the RichEditControl.Content property to a ViewModel property that stores HTML content. Use HtmlToContentConverter to convert HTML data to the control’s content.
" data-highlight-lines="[[10,15],[19]]" >
" >using System.ComponentModel; using System.Runtime.CompilerServices; // . public class HtmlViewModel : INotifyPropertyChanged < public HtmlViewModel() < htmlText = File.ReadAllText("Document.html", Encoding.UTF8); >public HtmlViewModel(string value) < htmlText = value; >private string htmlText; public string HtmlText < get < return htmlText; >set < htmlText = value; OnPropertyChanged("HtmlText"); >> public event PropertyChangedEventHandler PropertyChanged; private void OnPropertyChanged([CallerMemberName] string htmlText = null) < PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(htmlText)); >>
" >Imports System.ComponentModel Imports System.Runtime.CompilerServices ' . Public Class HtmlViewModel Implements INotifyPropertyChanged Sub New() html = File.ReadAllText("Document.html", Encoding.UTF8) End Sub Sub New(ByVal value As String) html = value End Sub Private html As String Public Property HtmlText() As String Get Return html End Get Set(ByVal value As String) html = value OnPropertyChanged("HtmlText") End Set End Property Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged Protected Sub OnPropertyChanged( Optional html As String = Nothing) PropertyChangedEvent?.Invoke(Me, New PropertyChangedEventArgs(html)) End Sub End Class
Method 2
" >using System.Net; // . using (var client = new WebClient()) < string html = client.DownloadString("https://docs.devexpress.com/WindowsForms/9610/"); richEditControl1.HtmlText = html; >
" >Imports System.Net ' . Using client As New WebClient() Dim html As String = client.DownloadString("https://docs.devexpress.com/WindowsForms/9610/") richEditControl1.HtmlText = html End Using
You can also use the following methods to insert HTML text into the document:
Define Import Options
The DXRichEditHtmlDocumentImporterOptions class contains options used to import an HTML document into the Rich Text Editor. You can use one of the following methods to specify these options:
" >using DevExpress.XtraRichEdit; using DevExpress.Xpf.RichEdit; using System.Text; // . richEditControl1.BeforeImport += (s, e) => < if (e.DocumentFormat == DocumentFormat.Html) < var options = (DXRichEditHtmlDocumentImporterOptions)e.Options; // Specify encoding. options.AutoDetectEncoding = false; options.Encoding = Encoding.UTF8; // Skip media rules. options.IgnoreMediaQueries = true; // Load images synchronously with HTML documents. options.AsyncImageLoading = false; // Preserve image resolution. options.ImageScalingDpi = 96; >>;
" >Imports DevExpress.XtraRichEdit Imports DevExpress.Xpf.RichEdit Imports System.Text ' . AddHandler richEditControl1.BeforeImport, Sub(s, e) If e.DocumentFormat = DocumentFormat.Html Then Dim options As HtmlDocumentImporterOptions = CType(e.Options, DXRichEditHtmlDocumentImporterOptions) ' Specify encoding. options.AutoDetectEncoding = False options.Encoding = Encoding.UTF8 ' Skip media rules. options.IgnoreMediaQueries = True ' Load images synchronously with HTML documents. options.AsyncImageLoading = False ' Preserve image resolution. options.ImageScalingDpi = 96 End If End Sub
Convert HTML To Another Format
After you load an HTML file to the Rich Text Editor, you can export the document to a different format.
Example 1. Convert HTML to PDF
Use the RichEditControl.ExportToPdf method to export HTML content to PDF. Pass a PdfExportOptions instance to the method to specify export options.
" >using DevExpress.XtraRichEdit.API.Native; using DevExpress.XtraRichEdit; // . Document document = richEditControl1.Document; // Load an HTML document. document.LoadDocument("HtmlDocument.html", DocumentFormat.Html); // Define PDF export options. var options = new DevExpress.XtraPrinting.PdfExportOptions(); options.ConvertImagesToJpeg = false; options.ImageQuality = DevExpress.XtraPrinting.PdfJpegImageQuality.Highest; // Specify page settings before export to PDF. document.Unit = DevExpress.Office.DocumentUnit.Inch; // Set page size. document.Sections[0].Page.Width = 8.5f; document.Sections[0].Page.Height = 11f; // Change margin settings. document.Sections[0].Margins.Top = 0; document.Sections[0].Margins.Bottom = 0; document.Sections[0].Margins.Left = 0.2f; document.Sections[0].Margins.Right = 0.2f; // Export the document to PDF. richEditControl1.ExportToPdf("PdfDocument.pdf", options);
" >Imports DevExpress.XtraRichEdit.API.Native Imports DevExpress.XtraRichEdit ' . Dim document As Document = richEditControl1.Document ' Load an HTML document. document.LoadDocument("HtmlDocument.html", DocumentFormat.Html) ' Define PDF export options. Dim options As New DevExpress.XtraPrinting.PdfExportOptions() options.ConvertImagesToJpeg = False options.ImageQuality = DevExpress.XtraPrinting.PdfJpegImageQuality.Highest ' Specify page settings before export to PDF. document.Unit = DevExpress.Office.DocumentUnit.Inch ' Set page size. document.Sections(0).Page.Width = 8.5F document.Sections(0).Page.Height = 11F ' Change margin settings. document.Sections(0).Margins.Top = 0 document.Sections(0).Margins.Bottom = 0 document.Sections(0).Margins.Left = 0.2F document.Sections(0).Margins.Right = 0.2F ' Export the document to PDF. richEditControl1.ExportToPdf("PdfDocument.pdf", options)
Example 2. Convert HTML to DOCX
" >using DevExpress.XtraRichEdit.API.Native; using DevExpress.XtraRichEdit; // . Document document = richEditControl1.Document; // Load an HTML document. document.LoadDocument("HtmlDocument.html", DocumentFormat.Html); // Modify and format the document. // . // Save the document as DOCX. document.SaveDocument("Document.docx", DocumentFormat.OpenXml);
" >Imports DevExpress.XtraRichEdit.API.Native Imports DevExpress.XtraRichEdit ' . Dim document As Document = richEditControl1.Document ' Load an HTML document. document.LoadDocument("HtmlDocument.html", DocumentFormat.Html) ' Modify and format the document. ' . ' Save the document as DOCX. document.SaveDocument("Document.docx", DocumentFormat.OpenXml)
Import Tips
- Implement and register a custom IUriStreamProvider to specify how to load images from an HTML document. For example, you can use this service when you import an HTML file that contains images referenced with a custom prefix.
If you import content from an HTTPS website, you may need to specify the security protocol enabled for this site. For example, if the site uses TLS 1.2 protocol, add the following line to your code:
" >System.Net.ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls12;
" >System.Net.ServicePointManager.SecurityProtocol = System.Net.ServicePointManager.SecurityProtocol Or SecurityProtocolType.Tls12
The HTML document is loaded in CompatibilityMode.ModeNotSpecified mode. In this case, the RichEdit Control uses the compatibility settings of previous Microsoft Word versions. Set the CompatibilitySettings.CompatibilityMode property to CompatibilityMode.Mode15 after the document is loaded to enable compatibility with the latest Microsoft Word version and process the document correctly:
" >richEditControl.Document.CompatibilitySettings.CompatibilityMode = CompatibilityMode.Mode15;
" >richEditControl.Document.CompatibilitySettings.CompatibilityMode = CompatibilityMode.Mode15
Export to HTML
Save as HTML File
Use the RichEditControl.SaveDocument method to export a document to HTML.
" >// Load a document. richEditControl1.LoadDocument("Document.docx"); // Export the document to a file in HTML format. richEditControl1.SaveDocument("HtmlDocument.html", DocumentFormat.Html); // Export the document to a file stream in HTML format. using (FileStream fileStream = new FileStream("HtmlDocument2.html", FileMode.Create))
" >' Load a document. richEditControl1.LoadDocument("Document.docx") ' Export the document to a file in HTML format. richEditControl1.SaveDocument("HtmlDocument.html", DocumentFormat.Html) ' Export the document to a file stream in HTML format. Using fileStream As New FileStream("HtmlDocument2.html", FileMode.Create) richEditControl1.SaveDocument(fileStream, DocumentFormat.Html) End Using
Return HTML Text
Use the RichEditControl.Document.HtmlText property or SubDocument.GetHtmlText method to convert document content to HTML.
" >// Load a document. richEditControl1.LoadDocument("Document.docx"); // Export the document to a file in HTML format. System.IO.File.WriteAllText("HtmlDocument.html", richEditControl1.Document.HtmlText);
" >' Load a document. richEditControl1.LoadDocument("Document.docx") ' Export the document to a file in HTML format. System.IO.File.WriteAllText("HtmlDocument.html", richEditControl1.Document.HtmlText)
Define Export Options
The DXRichEditHtmlDocumentExporterOptions class contains options used to export a document to HTML. You can use one of the following methods to specify these options:
" >using DevExpress.XtraRichEdit; using DevExpress.Xpf.RichEdit; // . richEditControl1.BeforeExport += (s, e) => < if (e.DocumentFormat == DocumentFormat.Html) < var options = (DXRichEditHtmlDocumentExporterOptions)e.Options; // Embed images in HTML pages. options.EmbedImages = true; // Specify how to export style sheets. options.CssPropertiesExportType = DevExpress.XtraRichEdit.Export.Html.CssPropertiesExportType.Style; // Specify the root tag for export. options.ExportRootTag = DevExpress.XtraRichEdit.Export.Html.ExportRootTag.Body; >>;
" >Imports DevExpress.XtraRichEdit Imports DevExpress.Xpf.RichEdit ' . AddHandler richEditControl1.BeforeExport, Sub(s, e) If e.DocumentFormat = DocumentFormat.Html Then Dim options As DXRichEditHtmlDocumentExporterOptions = CType(e.Options, HtmlDocumentExporterOptions) ' Embed images in HTML pages. options.EmbedImages = True ' Specify how to export style sheets. options.CssPropertiesExportType = DevExpress.XtraRichEdit.Export.Html.CssPropertiesExportType.Style ' Specify the root tag for export. options.ExportRootTag = DevExpress.XtraRichEdit.Export.Html.ExportRootTag.Body End If End Sub
Export Images
Embed Images
Enable the DXRichEditHtmlDocumentExporterOptions.EmbedImages option to embed images in an HTML file as Base64-encoded data.
Specify External Image Location
Method 1
Method 2
Implement and register a custom IUriProvider. This interface contains the CreateImageUri and CreateCssUri methods that allow you to specify locations for external images and styles.