System.Diagnostics.TraceListenerCollection Class

Summary

Provides a thread-safe list of TraceListener objects.

C# Syntax:

public class TraceListenerCollection : IList, ICollection, IEnumerable

The TraceListenerCollection list is used to specify the output listeners for the Trace.Listeners and the Debug.Listeners collections. You cannot create an instance of this class.

This list is thread-safe, however the methods used to access the list and the enumerator do not take synchronization locks. Instead, the collection is copied, the copy is modified, and a reference is set to the copy of the collection. Methods like TraceListenerCollection.Add, TraceListenerCollection.Remove, and TraceListenerCollection.Clear modify the elements in the collection.

The TraceListenerCollection class provides the TraceListenerCollection.Count property for information about the list. It also provides the following methods: TraceListenerCollection.Contains, TraceListenerCollection.GetEnumerator, TraceListenerCollection.IndexOf.

This class also provides the following methods to modify the list: TraceListenerCollection.Add, TraceListenerCollection.Clear, TraceListenerCollection.Insert, and TraceListenerCollection.Remove. The TraceListenerCollection.CopyTo method copies a part of the list to an array. The TraceListenerCollection.RemoveAt method deletes the list member at a specified index number.

The following example creates a TextWriterTraceListener that writes to the console screen. The code then adds the new listener to the Trace.Listeners.

/* Create a listener, which outputs to the console screen, and 
  * add it to the trace listeners. */
 TextWriterTraceListener myWriter = new 
    TextWriterTraceListener(System.Console.Out);
 Trace.Listeners.Add(myWriter);


    

System.Diagnostics Namespace | TraceListener | DefaultTraceListener | TextWriterTraceListener | Debug | Trace

System.Diagnostics.TraceListenerCollection Member List:

Public Properties

Count	Read-only Gets the number of listeners in the list.
Item	Read-only Overloaded: Item[string name] {get Gets the first TraceListener in the list with the specified name.
Item	Read-write Overloaded: Item[int i] {get Gets or sets the TraceListener at the specified index.

Public Methods

Add	Adds a TraceListener to the list.
AddRange	Overloaded: AddRange(TraceListener[] value) Adds an array of TraceListener objects to the list.
AddRange	Overloaded: AddRange(TraceListenerCollection value) Adds the contents of another TraceListenerCollection to the list.
Clear	Clears all the listeners from the list.
Contains	Checks whether the list contains the specified listener.
CopyTo	Copies a section of the current TraceListenerCollection list to the specified array at the specified index.
Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetEnumerator	Gets an enumerator for this list.
GetHashCode (inherited from System.Object)	See base class member description: System.Object.GetHashCode Derived from System.Object, the primary base class for all objects.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
IndexOf	Gets the index of the specified listener.
Insert	Inserts the listener at the specified index.
Remove	Overloaded: Remove(string name) Removes from the collection the first TraceListener with the specified name.
Remove	Overloaded: Remove(TraceListener listener) Removes from the collection the specified TraceListener.
RemoveAt	Removes from the collection the TraceListener at the specified index.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.

Protected Methods

Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.

Hierarchy:

• System.Object
• System.Diagnostics.TraceListenerCollection

System.Diagnostics.TraceListenerCollection Member Details

Summary

Gets the number of listeners in the list.

C# Syntax:

public int Count {get;}

Implements:

ICollection.Count

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Summary

Gets the first TraceListener in the list with the specified name.

C# Syntax:

public TraceListener this[string name] {get;}

name

The name of the TraceListener to get from the list.

The TraceListenerCollection.Item property is case-sensitive when searching for names. That is, if two listeners exist with the names "Lname" and "lname", TraceListenerCollection.Item property will find only the TraceListener with the TraceListener.Name that you specify, not both.

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Summary

Gets or sets the TraceListener at the specified index.

C# Syntax:

public TraceListener this[int i] {get; set;}

i

The zero-based index of the TraceListener to get from the list.

The index is zero-based. Therefore, you must subtract one from the numerical position of a particular TraceListener to access that TraceListener. For example, to get the third TraceListener, you need to specify myTraceListenerColl[2] .

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Summary

Adds a TraceListener to the list.

C# Syntax:

public int Add(    TraceListener listener );

listener

A TraceListener to add to the list.

Return Value:

The position at which the new listener was inserted.

The following example creates a TextWriterTraceListener that outputs to the console screen. The code then adds the new listener to the Trace.Listeners.

/* Create a listener, which outputs to the console screen, and 
  * add it to the trace listeners. */
 TextWriterTraceListener myWriter = new TextWriterTraceListener();
 myWriter.Writer = System.Console.Out;
 Trace.Listeners.Add(myWriter);
 

    

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Summary

Adds an array of TraceListener objects to the list.

C# Syntax:

public void AddRange(    TraceListener[] value );

value

An array of TraceListener objects to add to the list.

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Summary

Adds the contents of another TraceListenerCollection to the list.

C# Syntax:

public void AddRange(    TraceListenerCollection value );

value

Another TraceListenerCollection whose contents are added to the list.

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Summary

Clears all the listeners from the list.

C# Syntax:

public void Clear();

Implements:

IList.Clear

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Summary

Checks whether the list contains the specified listener.

C# Syntax:

public bool Contains(    TraceListener listener );

listener

A TraceListener to find in the list.

Return Value:

true if the listener is in the list; otherwise, false.

The TraceListenerCollection.Contains method can confirm the existence of a TraceListener before you perform further operations.

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Summary

Copies a section of the current TraceListenerCollection list to the specified array at the specified index.

C# Syntax:

public void CopyTo(    TraceListener[] listeners,    int index );

listeners

An array of type Array to copy the elements into. An array of type Array to copy the elements into.

index

The starting index number in the current list to copy from.

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Inherited
See base class member description: System.Object.Equals

C# Syntax:

public virtual bool Equals(    object obj );

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.Finalize

C# Syntax:

~TraceListenerCollection();

For more information on members inherited from System.Object click on the link above.

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Summary

Gets an enumerator for this list.

C# Syntax:

public IEnumerator GetEnumerator();

Return Value:

An enumerator of type IEnumerator.

Implements:

IEnumerable.GetEnumerator

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Inherited
See base class member description: System.Object.GetHashCode

C# Syntax:

public virtual int GetHashCode();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.GetType

C# Syntax:

public Type GetType();

For more information on members inherited from System.Object click on the link above.

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Summary

Gets the index of the specified listener.

C# Syntax:

public int IndexOf(    TraceListener listener );

listener

A TraceListener to find in the list.

Return Value:

The index of the listener, if it can be found in the list; otherwise, -1.

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Summary

Inserts the listener at the specified index.

C# Syntax:

public void Insert(    int index,    TraceListener listener );

index

The position in the list to insert the new TraceListener. The position in the list to insert the new TraceListener.

listener

A TraceListener to insert in the list.

Exceptions

Exception Type	Condition
ArgumentOutOfRangeException	The index is not a valid index in the list.

If the index equals the number of items in the list, then the listener is appended to the end of the list.

The index is zero-based. Therefore, if you want to insert the listener into the third position, you must call myTraceListenerColl.Insert(2, myNewListener) .

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Inherited
See base class member description: System.Object.MemberwiseClone

C# Syntax:

protected object MemberwiseClone();

For more information on members inherited from System.Object click on the link above.

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Summary

Removes from the collection the first TraceListener with the specified name.

C# Syntax:

public void Remove(    string name );

name

The name of the TraceListener to remove from the list.

Exceptions

Exception Type	Condition
ArgumentException	A listener with the given name does not exist in the list.

The name parameter is case-sensitive. That is, if two listeners exist with the names "Rname" and "rname", the TraceListenerCollection.Remove method will find the specific listener you name.

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Summary

Removes from the collection the specified TraceListener.

C# Syntax:

public void Remove(    TraceListener listener );

listener

A TraceListener to remove from the list.

Exceptions

Exception Type	Condition
ArgumentException	The listener does not exist in the list.

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Summary

Removes from the collection the TraceListener at the specified index.

C# Syntax:

public void RemoveAt(    int index );

index

The zero-based index of the TraceListener to remove from the list. The zero-based index of the TraceListener to remove from the list.

Exceptions

Exception Type	Condition
ArgumentOutOfRangeException	The index is not a valid index in the list.

Implements:

IList.RemoveAt

The index is zero-based. Therefore, you must subtract one from the numerical position of a particular TraceListener to delete that TraceListener. For example, to remove the third TraceListener, you need to specify myTraceListenerColl.RemoveAt(2) .

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Inherited
See base class member description: System.Object.ToString

C# Syntax:

public virtual string ToString();

For more information on members inherited from System.Object click on the link above.

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