Resolved Embedded Font code causing runtime error

[servantofone]

I grabbed some code to embed a font from the following discussion (Google cache of discussion):

Expert Exchange Embedded Font discussion

It works to embed the font; however, I now experience random crashes at runtime (in XP). If I comment out the calls to GetFont, then the crashes cease. If I uncomment the GetFont calls, it crashes randomly again.

Any insight you might provide would be great. I'm running Visual Studio 2008 Professional on XP Service Pack 3.

EmbeddedFont.vb

Imports System.Drawing.Text
Imports System.IO
Imports System.Reflection

Public Class EmbeddedFont
    Private Declare Auto Function AddFontMemResourceEx Lib "Gdi32.dll" _
        (ByVal pbFont As IntPtr, ByVal cbFont As Integer, _
        ByVal pdv As Integer, ByRef pcFonts As Integer) As IntPtr


    Public Shared Function GetFont(ByVal fontName As String) As FontFamily

        Dim exeCurrent As [Assembly] = [Assembly].GetExecutingAssembly()
        Dim nameSpc As String = exeCurrent.GetName().Name.ToString()
        Dim fontCollection As New PrivateFontCollection
        Dim loadStream As Stream = exeCurrent.GetManifestResourceStream( _
            nameSpc + "." + fontName)
        Dim byteBuffer(CType(loadStream.Length, Integer)) As Byte

        loadStream.Read(byteBuffer, 0, Int(CType(loadStream.Length, Integer)))

        Dim fontPtr As IntPtr = _
            Runtime.InteropServices.Marshal.AllocHGlobal( _
            Runtime.InteropServices.Marshal.SizeOf(GetType(Byte)) * _
                byteBuffer.Length)

        Runtime.InteropServices.Marshal.Copy(byteBuffer, 0, fontPtr, byteBuffer.Length)

        fontCollection.AddMemoryFont(fontPtr, byteBuffer.Length)

        Dim pcFonts As Int32 = 1

        AddFontMemResourceEx(fontPtr, byteBuffer.Length, 0, pcFonts)
        Runtime.InteropServices.Marshal.FreeHGlobal(fontPtr)
        Return fontCollection.Families(0)

    End Function

End Class

Runtime error:

System.AccessViolationException was unhandled
Message="Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
Source="System.Drawing"
StackTrace:
at System.Drawing.SafeNativeMethods.Gdip.GdipGetFamilyName(HandleRef family, StringBuilder name, Int32 language)
at System.Drawing.FontFamily.GetName(Int32 language)
at System.Drawing.FontFamily.get_Name()
at System.Windows.Forms.Internal.WindowsFont.FromFont(Font font, WindowsFontQuality fontQuality)
at System.Windows.Forms.Internal.WindowsGraphicsCacheManager.GetWindowsFont(Font font, WindowsFontQuality fontQuality)
at System.Windows.Forms.TextRenderer.DrawText(IDeviceContext dc, String text, Font font, Rectangle bounds, Color foreColor, TextFormatFlags flags)
at System.Windows.Forms.Label.OnPaint(PaintEventArgs e)
at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer, Boolean disposeEventArgs)
at System.Windows.Forms.Control.WmPaint(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.Label.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
at System.Windows.Forms.Form.DefWndProc(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ContainerControl.WndProc(Message& m)
at System.Windows.Forms.Form.WmSysCommand(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
at System.Windows.Forms.Form.DefWndProc(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ContainerControl.WndProc(Message& m)
at System.Windows.Forms.Form.WmNcButtonDown(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(ApplicationContext context)
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
at PromiseCard.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:

 

[servantofone]

I figured it out. I changed my code from:

lblLight1.Font = New Font(EmbeddedFont.GetFont("Light.ttf"), 39, FontStyle.Regular)
lblLight2.Font = New Font(EmbeddedFont.GetFont("Light.ttf"), 39, FontStyle.Regular)

to

Dim fontLight39 As New Font(EmbeddedFont.GetFont("Light.ttf"), 39, FontStyle.Regular)
lblLight1.Font = fontLight39
lblLight2.Font = fontLight39

That took care of the random crashing.