How to embed a True Type font（ 转载 ）

Some applications, for reasons of esthetics or a required visual style, will embed certain uncommon fonts so that they are always there when needed regardless of whether the font is actually installed on the destination system.

The secret to this is twofold. First the font needs to be placed in the resources by adding it to the solution and marking it as an embedded resource. Secondly, at runtime, the font is loaded via a stream and stored in a PrivateFontCollection object for later use.

This example uses a font which is unlikely to be installed on your system. Alpha Dance is a free True Type font that is available from the Free Fonts Collection. This font was embedded into the application by adding it to the solution and selecting the "embedded resource" build action in the properties.

Figure 1. The Alpha Dance font file embedded in the solution.

Once the file has been successfully included in the resources you need to provide a PrivateFontCollection object in which to store it and a method by which it's loaded into the collection. The best place to do this is probably the form load override or event handler. The following listing shows the process. Note how the AddMemoryFont method is used. It requires a pointer to the memory in which the font is saved as an array of bytes. In C# we can use the unsafe keyword for convienience but VB must use the capabilities of the Marshal classes unmanaged memory handling. The latter option is of course open to C# programmers who just don't like the unsafe keyword.

    PrivateFontCollection pfc = new PrivateFontCollection();

 

    private void Form1_Load(object sender, System.EventArgs e)

    {

      Stream fontStream = this.GetType().Assembly.GetManifestResourceStream("embedfont.Alphd___.ttf");

 

      byte[] fontdata = new byte[fontStream.Length];

      fontStream.Read(fontdata,0,(int)fontStream.Length);

      fontStream.Close();

      unsafe

      {

        fixed(byte * pFontData = fontdata)

        {

          pfc.AddMemoryFont((System.IntPtr)pFontData,fontdata.Length);

        }

      }

    }

 

  Dim pfc As New PrivateFontCollection()

 

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load

    'load the resource

    Dim fontStream As Stream = Me.GetType().Assembly.GetManifestResourceStream("embedfont.vb.Alphd___.ttf")

    'create an unsafe memory block for the data

    Dim data As System.IntPtr = Marshal.AllocCoTaskMem(fontStream.Length)

    'create a buffer to read in to

    Dim fontdata() As Byte

    ReDim fontdata(fontStream.Length)

    'fetch the font program from the resource

    fontStream.Read(fontdata, 0, fontStream.Length)

    'copy the bytes to the unsafe memory block

    Marshal.Copy(fontdata, 0, data, fontStream.Length)

    'pass the font to the font collection

    pfc.AddMemoryFont(data, fontStream.Length)

    'close the resource stream

    fontStream.Close()

    'free the unsafe memory

    Marshal.FreeCoTaskMem(data)

  End Sub

 

Fonts may have only certain styles which are available and unfortunately, selecting a font style that doesn't exist will throw an exception. To overcome this the font can be interrogated to see which styles are available and only those provided by the font can be used. The following listing demonstrates how the Alpha Dance font is used by checking the available font styles and showing all those that exist. Note that the underline and strikethrough styles are pseudo styles constructed by the font rendering engine and are not actually provided in glyph form.

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)

    {

      bool bold=false;

      bool regular=false;

      bool italic=false;

 

      e.Graphics.PageUnit=GraphicsUnit.Point;

      SolidBrush b = new SolidBrush(Color.Black);

 

      float y=5;

 

      System.Drawing.Font fn;

 

      foreach(FontFamily ff in pfc.Families)

      {

        if(ff.IsStyleAvailable(FontStyle.Regular))

        {

          regular=true;

          fn=new Font(ff,18,FontStyle.Regular);

          e.Graphics.DrawString(fn.Name,fn,b,5,y,StringFormat.GenericTypographic);

          fn.Dispose();

          y+=20;

        }

        if(ff.IsStyleAvailable(FontStyle.Bold))

        {

          bold=true;

          fn=new Font(ff,18,FontStyle.Bold);

          e.Graphics.DrawString(fn.Name,fn,b,5,y,StringFormat.GenericTypographic);

          fn.Dispose();

          y+=20;

        }

        if(ff.IsStyleAvailable(FontStyle.Italic))

        {

          italic=true;

          fn=new Font(ff,18,FontStyle.Italic);

          e.Graphics.DrawString(fn.Name,fn,b,5,y,StringFormat.GenericTypographic);

          fn.Dispose();

          y+=20;

        }

        if(bold  && italic)

        {

          fn=new Font(ff,18,FontStyle.Bold | FontStyle.Italic);

          e.Graphics.DrawString(fn.Name,fn,b,5,y,StringFormat.GenericTypographic);

          fn.Dispose();

          y+=20;

        }

        fn=new Font(ff,18,FontStyle.Underline);

        e.Graphics.DrawString(fn.Name,fn,b,5,y,StringFormat.GenericTypographic);

        fn.Dispose();

        y+=20;

        fn=new Font(ff,18,FontStyle.Strikeout);

        e.Graphics.DrawString(fn.Name,fn,b,5,y,StringFormat.GenericTypographic);

        fn.Dispose();

      }

 

      b.Dispose();

    }

 

  Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint

    Dim bold As Boolean = False

    Dim regular As Boolean = False

    Dim italic As Boolean = False

 

    e.Graphics.PageUnit = GraphicsUnit.Point

    Dim b As New SolidBrush(Color.Black)

 

    Dim y = 5

 

    Dim fn As System.Drawing.Font

    Dim ff As FontFamily

    For Each ff In pfc.Families

      If ff.IsStyleAvailable(FontStyle.Regular) Then

        regular = True

        fn = New Font(ff, 32, FontStyle.Regular)

        e.Graphics.DrawString(fn.Name, fn, b, 5, y, StringFormat.GenericTypographic)

        fn.Dispose()

        y += 40

      End If

      If ff.IsStyleAvailable(FontStyle.Bold) Then

        bold = True

        fn = New Font(ff, 32, FontStyle.Bold)

        e.Graphics.DrawString(fn.Name, fn, b, 5, y, StringFormat.GenericTypographic)

        fn.Dispose()

        y += 40

      End If

      If ff.IsStyleAvailable(FontStyle.Italic) Then

        italic = True

        fn = New Font(ff, 32, FontStyle.Italic)

        e.Graphics.DrawString(fn.Name, fn, b, 5, y, StringFormat.GenericTypographic)

        fn.Dispose()

        y += 40

      End If

      If bold And italic Then

        fn = New Font(ff, 32, FontStyle.Bold Or FontStyle.Italic)

        e.Graphics.DrawString(fn.Name, fn, b, 5, y, StringFormat.GenericTypographic)

        fn.Dispose()

        y += 40

      End If

      fn = New Font(ff, 32, FontStyle.Underline)

      e.Graphics.DrawString(fn.Name, fn, b, 5, y, StringFormat.GenericTypographic)

      fn.Dispose()

      y += 40

      fn = New Font(ff, 32, FontStyle.Strikeout)

      e.Graphics.DrawString(fn.Name, fn, b, 5, y, StringFormat.GenericTypographic)

      fn.Dispose()

    Next

 

    b.Dispose()

  End Sub

 

Figure 2 shows the application in action.

Figure 2. The embedded Alpha Dance font.