log4net SDK Reference |

# MDC.Set Method

Add an entry to the MDC

[Visual Basic]
Public Shared Sub Set( _
ByVal key As String, _
ByVal value As String _
)
[C#]
public static void Set(
string key,
string value
);

#### Parameters

key
  The key to store the value under.
value
  The value to store.

#### Remarks

> Note

> The MDC is deprecated and has been replaced by the Properties. The current MDC implementation forwards to the `ThreadContext.Properties`.

Puts a context value (the val parameter) as identified with the key parameter into the current thread's context map.

If a value is already defined for the key specified then the value will be replaced. If the val is specified as `null` then the key value mapping will be removed.

#### See Also

MDC Class | log4net Namespace