Class NDC

Namespace

log4net

Assembly

log4net.dll

Implementation of Nested Diagnostic Contexts.

public sealed class NDC

Inheritance

object

NDC

Inherited Members

object.GetType()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Examples

How to push a message into the context

        <pre><code class="lang-csharp">using(NDC.Push("my context message"))

{ ... all log calls will have 'my context message' included ...

} // at the end of the using block the message is automatically removed

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

A Nested Diagnostic Context, or NDC in short, is an instrument to distinguish interleaved log output from different sources. Log output is typically interleaved when a server handles multiple clients near-simultaneously.

Interleaved log output can still be meaningful if each log entry from different contexts had a distinctive stamp. This is where NDCs come into play.

Note that NDCs are managed on a per thread basis. The NDC class is made up of static methods that operate on the context of the calling thread.

Properties

Depth

Gets the current context depth.

public static int Depth { get; }

Property Value

int

The current context depth.

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

The number of context values pushed onto the context stack.

Used to record the current depth of the context. This can then be restored using the SetMaxDepth(int) method.

See Also

SetMaxDepth(int)

Methods

Clear()

Clears all the contextual information held on the current thread.

public static void Clear()

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

Clears the stack of NDC data held on the current thread.

CloneStack()

Creates a clone of the stack of context information.

public static Stack CloneStack()

Returns

Stack

A clone of the context info for this thread.

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

The results of this method can be passed to the Inherit(Stack) method to allow child threads to inherit the context of their parent thread.

Inherit(Stack)

Inherits the contextual information from another thread.

public static void Inherit(Stack stack)

Parameters

stack Stack

The context stack to inherit.

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

This thread will use the context information from the stack supplied. This can be used to initialize child threads with the same contextual information as their parent threads. These contexts will NOT be shared. Any further contexts that are pushed onto the stack will not be visible to the other. Call CloneStack() to obtain a stack to pass to this method.

Pop()

Removes the top context from the stack.

public static string Pop()

Returns

string

The message in the context that was removed from the top of the stack.

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

Remove the top context from the stack, and return it to the caller. If the stack is empty then an empty string (not null) is returned.

Push(string)

Pushes a new context message.

public static IDisposable Push(string message)

Parameters

message string

The new context message.

Returns

IDisposable

An IDisposable that can be used to clean up the context stack.

Examples

Simple example of using the Push method with the using keyword.

        <pre><code class="lang-csharp">using(log4net.NDC.Push("NDC_Message"))

{ log.Warn("This should have an NDC message"); }

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

Pushes a new context onto the context stack. An IDisposable is returned that can be used to clean up the context stack. This can be easily combined with the using keyword to scope the context.

Remove()

Removes the context information for this thread. It is not required to call this method.

public static void Remove()

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

This method is not implemented.

SetMaxDepth(int)

Forces the stack depth to be at most maxDepth.

public static void SetMaxDepth(int maxDepth)

Parameters

maxDepth int

The maximum depth of the stack

Remarks

note

The NDC is deprecated and has been replaced by the Stacks. The current NDC implementation forwards to the ThreadContext.Stacks["NDC"].

Forces the stack depth to be at most maxDepth. This may truncate the head of the stack. This only affects the stack in the current thread. Also it does not prevent it from growing, it only sets the maximum depth at the time of the call. This can be used to return to a known context depth.