Binding.NullValue Property
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
The data source must contain DBNull for the NullValue property to be correctly applied. If the data source type is a type such as a string or integer the value of the NullValue property will be ignored. Also, the NullValue property is ignored if it is set to null.
A null value will be added to the data source when the control property is set to the object of NullValue. If NullValue is set to a string value, comparisons are case-insensitive.
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.