Convert::IsDBNull Method
Returns an indication whether the specified object is of type DBNull.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
- Type: System::Object
An object.
The IsDBNull method tests whether the value parameter is equal to DBNull::Value. It is equivalent to the following code:
Note |
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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.
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.
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