This documentation is archived and is not being maintained.

Convert::IsDBNull Method

Returns an indication whether the specified object is of type DBNull.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

static bool IsDBNull(
	Object^ value


Type: System::Object
An object.

Return Value

Type: System::Boolean
true if value is of type DBNull; otherwise, false.

The IsDBNull method tests whether the value parameter is equal to DBNull::Value. It is equivalent to the following code:

No code example is currently available or this language may not be supported.

DBNull::Value is used to indicate a value that is missing. It is not equivalent to nullptr or to String::Empty.

The following example uses a SqlDataReader object to retrieve survey data from a database. It assigns each row's field values to an array, and then passes each array element to the IsDBNull method. If the method returns true, the example assigns the string "NA" to the array element. The array is then added to the Rows collection of a System.Windows.Forms::DataGridView control.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

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

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.