The Font property is an ambient property. An ambient property is a control property that, if not set, is retrieved from the parent control. For example, a Button will have the same BackColor as its parent Form by default. For more information about ambient properties, see the AmbientProperties class or the Control class overview.

Because the Font is immutable (meaning that you cannot adjust any of its properties), you can only assign the Font property a new Font. However, you can base the new font on the existing font.

[Visual Basic, C#]

The following is an example of how to adjust the existing font to make it bold:

myControl.Font = new Font(myControl.Font, 
    myControl.Font.Style | FontStyle.Bold);

MyControl.Font = New Font(MyControl.Font, _ 
    MyControl.Font.Style Or FontStyle.Bold)

When overriding the Font property in a derived class, use the base class's Font property to extend the base implementation. Otherwise, you must provide all the implementation. You are not required to override both the get and set accessors of the Font property; you can override only one if needed.

The following code example displays a FontDialog to the user and changes the Font of a DateTimePicker control. This example requires that you have a Form with Button and a DateTimePicker on it.

Private Sub myButton_Click(sender As Object, e As EventArgs)
   Dim myFontDialog As FontDialog
   myFontDialog = New FontDialog()

   If myFontDialog.ShowDialog() = DialogResult.OK Then
      ' Set the control's font.
      myDateTimePicker.Font = myFontDialog.Font
   End If
End Sub

private void myButton_Click(object sender, EventArgs e)
{
   FontDialog myFontDialog = new FontDialog();
   if(myFontDialog.ShowDialog() == DialogResult.OK)
   {
      // Set the control's font.
      myDateTimePicker.Font = myFontDialog.Font;
   }
}

private:
   void myButton_Click( Object^ sender, EventArgs^ e )
   {
      FontDialog^ myFontDialog = gcnew FontDialog;
      if ( myFontDialog->ShowDialog() == ::DialogResult::OK )
      {
         // Set the control's font.
         myDateTimePicker->Font = myFontDialog->Font;
      }
   }

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference