JavascriptCallbackBehaviorAttribute Class

.NET Framework (current version)

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A contract behavior that allows you to set the URL query string parameter name to something other than the default “callback”.

Namespace:   System.ServiceModel.Web
Assembly:  System.ServiceModel.Web (in System.ServiceModel.Web.dll)


<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple := False)>
Public NotInheritable Class JavascriptCallbackBehaviorAttribute
	Inherits Attribute
	Implements IContractBehavior


Initializes a new instance of the JavascriptCallbackBehaviorAttribute class.


When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)


Gets or sets the URL query string parameter name to use for cross-domain script access.

System_CAPS_pubmethodAddBindingParameters(ContractDescription, ServiceEndpoint, BindingParameterCollection)

An implementation of the AddBindingParameters method.

System_CAPS_pubmethodApplyClientBehavior(ContractDescription, ServiceEndpoint, ClientRuntime)

An implementation of the ApplyClientBehavior method.

System_CAPS_pubmethodApplyDispatchBehavior(ContractDescription, ServiceEndpoint, DispatchRuntime)

An implementation of the ApplyDispatchBehavior method.


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethodValidate(ContractDescription, ServiceEndpoint)

An implementation of the Validate method.

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

JSONP is a mechanism used to enable cross-site, scripting support in Web browsers. It involves sending a request with a callback function name provided as a URL query string parameter value. The service returns a response with the usual JSON payload wrapped in the call to the provided callback function as if it were a line of executable code.

The following is an example of a URL used to call a service: http://baseAddress/Service/RESTService?callback=functionName. When invoked, the service responds with the following JSON.

functionName({ “root”:”Something});

The JavascriptCallbackBehaviorAttribute allows developers to specify the name of the URL query string parameter to interpret as the callback parameter. The default value is “callback” (not case sensitive).

The following example shows how this attribute is applied to a service contract.

public class Service1
    public string GetData()
         // ...

This attribute only applies when it marks a service contract type that is used with the WebHttpBinding and the CrossDomainScriptAccessEnabled property of the binding is set to true.

.NET Framework
Available since 4.0

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

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