ThreadStaticAttribute Class

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Indicates that the value of a static field is unique for each thread.

Inheritance Hierarchy


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


<AttributeUsageAttribute(AttributeTargets.Field, Inherited := False)> _
Public Class ThreadStaticAttribute _
    Inherits Attribute
[AttributeUsageAttribute(AttributeTargets.Field, Inherited = false)]
public class ThreadStaticAttribute : Attribute

The ThreadStaticAttribute type exposes the following members.


Name Description
ThreadStaticAttribute Initializes a new instance of the ThreadStaticAttribute class.



Name Description
Equals Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
GetHashCode Returns the hash code for this instance. (Inherited from Attribute.)
GetType Gets the Type of the current instance. (Inherited from Object.)
Match When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
ToString Returns a string that represents the current object. (Inherited from Object.)



A static field (Shared in Visual Basic) marked with ThreadStaticAttribute is not shared between threads. Each executing thread has a separate instance of the field, and independently sets and gets values for that field. If the field is accessed on a different thread, it will contain a different value.


Do not specify initial values for fields marked with ThreadStaticAttribute, because such initialization occurs only once, when the class constructor executes, and therefore affects only one thread. If you do not specify an initial value, you can rely on the field being initialized to its default value if it is a value type, or to nullNothingnullptra null reference (Nothing in Visual Basic) (Nothing in Visual Basic) if it is a reference type.

Use this attribute as it is, and do not derive from it. The following is an example of ThreadStaticAttribute syntax:

static int value;
<ThreadStatic> _
Shared value As Integer

Version Notes

Windows Phone

ThreadStaticAttribute is not supported in Windows Phone.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0


Windows Phone

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also


System Namespace