Load and Use Custom Fonts Without Installation on the System
- 10 minutes to read
DevExpress Office File API allows you to use custom fonts in your documents. The following font formats are available:
- TrueType fonts (.TTF)
- OpenType fonts that use TrueType or CFF (Compact Font Format) glyph outlines (.OTF)
- OpenType Font Collections (.TTC, .OTC) that contain multiple fonts in a single file
Variable fonts (VF) are not supported.
#Install a Font
You can install the required font on your machine or server to use in a document. Follow the instructions below for your operating system.
#Windows
Download font files. If font files are zipped, right-click the .zip folder and then click Extract to unzip them. If you are prompted to allow the program to make changes to your computer, and if you trust the source of the font, click Yes. Re-login to complete the installation.
Note
The Windows Server OS installs fonts on a per-user basis. Make sure that the font is installed for all users or for the user who runs the application.
#Linux
Install the fontconfig
library to manage fonts. Copy the font file in the fonts directory and then refresh the font cache. In the Linux docker file, you can use the usr/local/share/fonts/ directory, and the following commands:
COPY ["FontsFolderNameHere/MyFontFileName.ttf", "usr/local/share/fonts/"]
RUN apt-get -y install fontconfig
RUN fc-cache -vf
Different Linux distributions use slightly different commands:
sudo apt-get -y install fontconfig
cp <font name> ~/.local/share/fonts
fc-cache -vfkq
You can install the ttf-mscorefonts-installer
package to add Microsoft TrueType core fonts (Arial, Times New Roman, Courier New, and so on) to your system. Run the following terminal command to install this package and accept the license agreement:
You can also use the SkiaSharp library to use fonts without fontconfig
installation. Add the SkiaSharp.NativeAssets.Linux.NoDependencies
package to your project. Copy font files to the /usr/share/fonts folder. The Skia library automatically uses fonts from this folder.
#Use a Font Without Installation
The Word Processing Document API and Spreadsheet Document API ship with the DXFontRepository class that allows you to use fonts that are not installed on the current operating system. When you load a document that uses such fonts, the RichEditDocumentServer and Workbook components substitute missing fonts with the fonts available on the current machine. The DXFontRepository class allows you to load and use custom fonts in your application to prevent font substitution when documents are printed or exported to PDF.
Use the DXFontRepository.Instance static property to access a DXFontRepository instance.
#Add Fonts to the Font Repository
Use the DXFontRepository.AddFont method overloads to add fonts to the font repository. You can load a font from a file, stream, or byte array.
Supported font formats include:
- TrueType fonts (.TTF)
- OpenType fonts that use CFF (Compact Font Format) glyph outlines (.OTF)
- OpenType Font Collections (.TTC, .OTC) that contain multiple fonts in a single file
To avoid excessive document layout recalculations, add fonts to DXFontRepository before you load a document that uses these fonts.
Note
Loaded fonts are not saved to the document. These fonts are used to print or export the document to PDF.
#Example 1: Use Custom Fonts in the Word Processing Document API
The following example adds custom fonts to DXFontRepository and uses these fonts to format document paragraphs. The resulting document is exported to PDF. This example uses the following Google fonts:
using DevExpress.Drawing;
using DevExpress.XtraRichEdit;
using DevExpress.XtraRichEdit.API.Native;
using System.Drawing;
namespace ConsoleOfficeApp {
class Program {
static void Main(string[] args) {
DXFontRepository.Instance.AddFont(@"Fonts\EmilysCandy-Regular.ttf");
DXFontRepository.Instance.AddFont(@"Fonts\FrederickatheGreat-Regular.ttf");
using (var wordProcessor = new RichEditDocumentServer())
{
Document document = wordProcessor.Document;
// Load a document.
document.LoadDocument(@"Documents\Alice in Wonderland.docx");
// Format the first paragraph, which contains the book title.
var titleFormatting =
document.BeginUpdateCharacters(document.Paragraphs[0].Range);
FormatCharacters(titleFormatting, 20,
"Fredericka the Great", Color.FromArgb(0x2E, 0x74, 0xB5));
document.EndUpdateCharacters(titleFormatting);
// Format the second paragraph, which contains the author's name.
var subtitleFormatting =
document.BeginUpdateCharacters(document.Paragraphs[1].Range);
FormatCharacters(subtitleFormatting, 14,
"Emilys Candy", Color.FromArgb(0x3B, 0x38, 0x38));
document.EndUpdateCharacters(subtitleFormatting);
// Export the document to PDF.
wordProcessor.ExportToPdf(@"Documents\Alice in Wonderland.pdf");
}
DXFontRepository.Instance.Dispose();
}
private static void FormatCharacters(CharacterProperties formatting,
float size, string fontName, Color color)
{
formatting.FontSize = size;
formatting.FontName = fontName;
formatting.ForeColor = color;
}
}
}
The following image demonstrates the result:
#Example 2: Use Custom Fonts in the Spreadsheet Document API
The following example adds custom fonts to DXFontRepository and uses these fonts to format cells in a workbook. The resulting document is exported to PDF. This example uses the following Google fonts:
using DevExpress.Drawing;
using DevExpress.Spreadsheet;
namespace ConsoleOfficeApp {
class Program {
static void Main(string[] args) {
DXFontRepository.Instance.AddFont(@"Fonts\advent-pro.regular.ttf");
DXFontRepository.Instance.AddFont(@"Fonts\Roboto-Light.ttf");
using (Workbook workbook = new Workbook())
{
// Load a workbook.
workbook.LoadDocument(@"Documents\Sales Report.xlsx", DocumentFormat.Xlsx);
Worksheet worksheet = workbook.Worksheets["Report"];
// Return the cell that contains the document title.
Cell cell = worksheet.Cells["B2"];
// Specify font settings (font name and size).
cell.Font.Name = "Advent Pro";
cell.Font.Size = 26;
// Return the cell range that contains report data.
CellRange range = worksheet.Range["B4:F20"];
// Start range format update.
var rangeFormatting = range.BeginUpdateFormatting();
// Specify font settings (font name and size).
rangeFormatting.Font.Name = "Roboto Light";
rangeFormatting.Font.Size = 14;
// End range format update.
range.EndUpdateFormatting(rangeFormatting);
// Export the document to PDF.
workbook.ExportToPdf(@"Documents\Sales Report.pdf");
}
DXFontRepository.Instance.Dispose();
}
}
}
The following image demonstrates the result:
#Identify Missing Fonts and Add Them to the Repository
Your document design and layout may rely on a font type that is not available in the application’s hosting environment. As a result, the font cannot be installed on the client machine, in a Docker image, in Azure, or in another host/container. In such cases, your document replaces unavailable fonts with default fonts, which may alter the appearance of a document from the original design.
The DXFontRepository
contains a mechanism to ensure that a document uses the correct fonts regardless of the hosting environment. A document will notify the application about missing typefaces so that you can obtain the required font data. Once you obtain these fonts, add them to the DXFontRepository
, thus making them available to DevExpress controls.
The DXFontRepository.QueryNotFoundFont event fires for every unavailable font type. Handle this event to do the following:
- Identify the missing typeface and its suggested alternative (e.RequestedFont and e.ActualFont)
- Obtain the required font file from a font hosting service (such as Google Fonts)
- Prepare a byte array and pass it to e.FontFileData
This implementation ensures that DXFontRepository
contains all required font types before document generation begins.
The following code sample contains simple code that registers the preloaded “Sankofa Display” font in case it is unavailable in the application environment:
private static void Report_QueryNotFoundFont(object sender, NotFoundFontEventArgs e) {
if (e.RequestedFont == "Sankofa Display") {
string font = Environment.CurrentDirectory + "\\Data\\SankofaDisplay-Regular.ttf";
e.FontFileData = File.ReadAllBytes(font);
}
}
#Obtain Missing Fonts from a Font Hosting Service (Google Fonts)
You can use the DXFontRepository.QueryNotFoundFont event to identify missing fonts and download them from a hosting service. The following example implements a service that asynchronously downloads missing fonts from Google Fonts and adds them to DXFontRepository.
Use your personal Google API Key to run this example. For instructions on how to obtain your key, see Google Fonts Developer API.
Assign your API Key to the apiKey
variable in the FontCollectorService.cs
file before you launch the example.
Review license agreements associated with fonts that you use. Use and redistribution permissions may vary. The service used in this example (Google Fonts) hosts fonts that are open source and available at no cost. Review the following page for details: Google Fonts FAQ.
The report in this example contains a few fonts that may be missing in many hosting environments: Ga Maamli, Roboto, and Nerko One. The example obtains these fonts if missing and makes them available to report controls. When exported to PDF, the report uses the original fonts.
#Obtain Information About Fonts in the Repository
Use the DXFontRepository.GetFonts method to return a list of all fonts in the font repository. Each item in this list is a DXFontData object that contains font information.
The following code sample retrieves the names of all fonts in the repository and displays this information in the console window:
using DevExpress.Drawing;
using System;
using System.Collections.Generic;
// ...
if (DXFontRepository.Instance.IsEmpty)
Console.WriteLine("Font repository is empty.");
else
{
Console.WriteLine("Font repository contains the following fonts:");
IList<FontData> fonts = DXFontRepository.Instance.GetFonts();
for (int i = 0; i < fonts.Count; i++)
{
Console.WriteLine($" \u002A {fonts[i].Name}");
}
}
The following image demonstrates a sample console output:
#Clear the Font Repository
Call the DXFontRepository.Clear method to remove all fonts from the font repository. Use the DXFontRepository.IsEmpty property to check whether the repository contains fonts.
using DevExpress.Drawing;
// ...
// Check whether the font repository is empty.
if (!DXFontRepository.Instance.IsEmpty)
// If false, clear the font repository.
DXFontRepository.Instance.Clear();