How to properly render an embedded Font? - vb.net

Question

I download a True Type Font and I embedded it just as this page explains.
I had to set the UseCompatibleTextRendering property to be able to load it but it looks very weird, I don't know why it looks good in the browser but not in the application.
Just to be clear I added the font to my resources, set it as embedded resource, I used this module:
Imports System.IO
Imports System.Reflection
Imports System.Drawing.Text
Imports System.Runtime.InteropServices
Module ExternalFontType
Public Function GetFont(aAssembly As Assembly,
strFontName As String, intFontSize As Integer,
fsFontStyle As FontStyle) As Font
Using pcolFonts As New PrivateFontCollection
Dim bFont() As Byte = ExternalFontType.bRawFontData(aAssembly, strFontName)
Dim ptrMemFont As IntPtr =
Marshal.AllocCoTaskMem(bFont.Length)
Marshal.Copy(bFont, 0, ptrMemFont, bFont.Length)
pcolFonts.AddMemoryFont(ptrMemFont, bFont.Length)
Marshal.FreeCoTaskMem(ptrMemFont)
Return New Font(pcolFonts.Families(0),
intFontSize, fsFontStyle)
End Using
End Function
Private Function bRawFontData(aAssembly As Assembly, strFontName As String) As Byte()
Using stFont As Stream =
aAssembly.GetManifestResourceStream(strFontName)
If (stFont Is Nothing) Then Throw _
New Exception(String.Format("Cannot load _
font '{0}'", strFontName))
Dim bFontBuffer() As Byte = New _
Byte(CInt(stFont.Length - 1)) {}
stFont.Read(bFontBuffer, 0, CInt(stFont.Length))
Return bFontBuffer
End Using
End Function
End Module
and included it in this code
lbl.UseCompatibleTextRendering = True
lbl.Font = ExternalFontType.GetFont(Me.GetType.Assembly, "ProyectName.FontName.ttf", 15, FontStyle.Bold)

Answer 1

More than one problem with that code:
The PrivateFontCollection cannot be declared with a Using statement: this collection must be preserved as long as the Fonts it points to are needed. It's usually declared as a Field in the class (Form) that uses it or in a shared class (or Module, here), then disposed of when not needed anymore.
Marshal.FreeCoTaskMem() cannot be used here; it's a temptation to call it after Marshal.AllocCoTaskMem(), but not in this occasion. This can (will) compromise the Font data allocation. What you need to do is dispose of the PrivateFontcollection object. The Framework will take care of the COM affair (it will do it for you even if you forget to dispose of the PrivateFontcollection object. You should try not to forget, though).
The assembly reference is not required: the Font is added to the Project's Resources as a byte array, which is all that's needed. It can then be retrieved either by name, e.g., My.Resources.SomeFontName, or using the ResourceManager.GetObject() method, casting the returned object to Byte():
Dim fontData As Byte() = My.Resources.SomeFontName
Dim fontData As Byte() = DirectCast(My.Resources.ResourceManager.GetObject("SomeFontName"), Byte())
▶ You have already mentioned this but let's say it again: not all controls can use these Fonts. Only controls that can use Fonts drawn by GDI+ can actually use Fonts from the PrivateFontCollection, the Label and Button controls are among of these, in fact both expose a UseCompatibleTextRendering property. A RichTextBox, for example, cannot.
If the Font is created correctly, you can use Graphics.DrawString() to draw strings content using that Font, even when you cannot set it as the Font of a Control.
Private myFontCollection As PrivateFontCollection = New PrivateFontCollection()
In the Form's Constructor, add Font from the Project's Resources.
Here I'm using a helper class, FontManager, which exposes a public shared method AddFontsFromResource(): pass to this method the PrivateFontCollection and a list of resources names corresponding to the Font names.
This method fills the collection with Fonts that can be installed successfully and returns the number of Fonts installed.
Of course you use whatever other method you prefer to reference your Fonts.
Note. In the example, three Font resources are added to the collection:
{"FontFamily1Regular", "FontFamily1Italics", "OtherFontFamily"}
but two belong to the same FontFamily, so the PrivateFontCollection will contain just two elements, not three.
Public Sub New()
Dim installedFontsCount = FontManager.AddFontsFromResources(myFontCollection,
{"FontFamily1Regular", "FontFamily1Italics", "OtherFontFamily"})
' The Font can set here or anywhere else
someLabel.UseCompatibleTextRendering = True
someLabel.Font = New Font(myFontCollection.Families(0), 10.5F, FontStyle.Regular)
someButton.UseCompatibleTextRendering = True
someButton.Font = New Font(myFontCollection.Families(0), 10.5F, FontStyle.Italic)
End Sub
It's important to dispose of the PrivateFontCollection when it's not needed anymore: when the Form that initialized it closes or before the Application closes:
You could also use a shared object to reference a PrivateFontCollection that can be used anywhere in the Project. In this case the collection needs to be disposed of when the Application closes.
Private Sub Form1_FormClosed(sender As Object, e As FormClosedEventArgs) Handles MyBase.FormClosed
myFontCollection.Dispose()
End Sub
Helper class:
Imports System.Drawing.Text
Imports System.Runtime.InteropServices
Public Class FontManager
Public Shared Function AddFontsFromResources(fontCollection As PrivateFontCollection, fontNames As String()) As Integer
If fontNames.Length = 0 Then Return Nothing
Dim installedFontsCount = 0
For Each fontName As String In fontNames
Try
Dim fontData As Byte() = CType(My.Resources.ResourceManager.GetObject(fontName), Byte())
If fontData Is Nothing Then Throw New InvalidOperationException()
Dim data As IntPtr = Marshal.AllocCoTaskMem(fontData.Length)
Marshal.Copy(fontData, 0, data, fontData.Length)
fontCollection.AddMemoryFont(data, fontData.Length)
installedFontsCount += 1
Catch ex As Exception
' Placeholder: Notify User/Log/Whatever
Debug.Print($"Font installation failed for {fontName}")
End Try
Next
Return installedFontsCount
End Function
End Class
C# version:
using System.Drawing.Text;
using System.Runtime.InteropServices;
public static int AddFontsFromResources(PrivateFontCollection fontCollection, string[] fontNames)
{
int installedFontsCount = 0;
if (fontNames.Length == 0) return 0;
foreach (string fontName in fontNames) {
try {
byte[] fontData = (byte[])Properties.Resources.ResourceManager.GetObject(fontName);
var data = Marshal.AllocCoTaskMem(fontData.Length);
Marshal.Copy(fontData, 0, data, fontData.Length);
fontCollection.AddMemoryFont(data, fontData.Length);
installedFontsCount += 1;
}
catch (Exception) {
// Placeholder: Notify User/Log/Whatever
Console.WriteLine($"Font installation failed for {fontName}");
}
}
return installedFontsCount;
}