This property is automatically set to true if the Opacity is changed. When the opacity of a form is set using the Opacity property, the form will layer objects on the form. If you set the AllowTransparency property to false the form will not be in layered mode which will improve the display performance of the form.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.