Switch<T> Class

Definition

Namespace:

System.Activities.Statements

Assembly:

System.Activities.dll

Selects one choice from a number of activities to execute, based on the value of a given expression of the type specified in this object's type specifier.

generic <typename T>
public ref class Switch sealed : System::Activities::NativeActivity

[System.Windows.Markup.ContentProperty("Cases")]
public sealed class Switch<T> : System.Activities.NativeActivity

[<System.Windows.Markup.ContentProperty("Cases")>]
type Switch<'T> = class
    inherit NativeActivity

Public NotInheritable Class Switch(Of T)
Inherits NativeActivity

Type Parameters

T

The type of the values provided in the Cases collection.

Inheritance

Object

Activity

NativeActivity

Switch<T>

Attributes

ContentPropertyAttribute

Examples

The following code sample demonstrates creating a Switch<T> activity.

// check if the number is ok...
new Switch<int>()
{
    DisplayName = "Verify Value from User",
    Expression = ExpressionServices.Convert<int>( env => numberFromUser.Get(env).CompareTo(numberToGuess.Get(env)) ),
    Cases =
    {
        { 0, new Assign<bool>()
            {
                To = new OutArgument<bool>(finished),
                Value = true
            }
        },
        {  1, new WriteLine() { Text = "    Try a lower number number..." } },
        { -1, new WriteLine() { Text = "    Try a higher number" } }
    }
}

Remarks

Each case in the Cases dictionary consists of a value (serving as the key for the dictionary) and an activity (serving as the value for the dictionary). The Expression is evaluated and compared against the keys in the Cases dictionary. If a match is found, the corresponding activity is executed. Every key in the Cases dictionary must be unique according to the dictionary's equality comparer.

Constructors

Switch<T>()	Creates a new instance of the Switch<T> class.
Switch<T>(Activity<T>)	Creates a new instance of the Switch<T> class with the specified expression.
Switch<T>(Expression<Func<ActivityContext,T>>)	Creates a new instance of the Switch<T> class with the specified expression.
Switch<T>(InArgument<T>)	Creates a new instance of the Switch<T> class with the specified expression.

Properties

CacheId	Gets the identifier of the cache that is unique within the scope of the workflow definition. (Inherited from Activity)
CanInduceIdle	Gets or sets a value that indicates whether the activity can cause the workflow to become idle. (Inherited from NativeActivity)
Cases	Represents the dictionary of potential execution paths. Each entry contains a key and an activity that is executed when the result of the expression matches the key.
Constraints	Gets a collection of Constraint activities that can be configured to provide validation for the Activity. (Inherited from Activity)
Default	Represents the activity that is executed if no keys of entries in the Cases collection match the Expression property.
DisplayName	Gets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking. (Inherited from Activity)
Expression	Gets the object to compare to the keys in the Cases collection.
Id	Gets an identifier that is unique in the scope of the workflow definition. (Inherited from Activity)
Implementation	The execution logic of the activity. (Inherited from NativeActivity)
ImplementationVersion	Gets or sets the implementation version of the activity. (Inherited from NativeActivity)

Methods

Abort(NativeActivityAbortContext)	When implemented in a derived class, takes actions in response to the activity being aborted. (Inherited from NativeActivity)
CacheMetadata(ActivityMetadata)	Not implemented. Use the CacheMetadata(NativeActivityMetadata) method instead. (Inherited from NativeActivity)
CacheMetadata(NativeActivityMetadata)	Creates and validates a description of the activity's arguments, variables, child activities, and activity delegates. (Inherited from NativeActivity)
Cancel(NativeActivityContext)	When implemented in a derived class, runs logic to cause graceful early completion of the activity. (Inherited from NativeActivity)
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
Execute(NativeActivityContext)	When implemented in a derived class, runs the activity's execution logic. (Inherited from NativeActivity)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
OnCreateDynamicUpdateMap(NativeActivityUpdateMapMetadata, Activity)	Raises an event when creating a map for the dynamic update. (Inherited from NativeActivity)
OnCreateDynamicUpdateMap(UpdateMapMetadata, Activity)	Raises an event when creating a map for the dynamic update. (Inherited from NativeActivity)
ShouldSerializeDisplayName()	Indicates whether the DisplayName property should be serialized. (Inherited from Activity)
ToString()	Returns a String that contains the Id and DisplayName of the Activity. (Inherited from Activity)
UpdateInstance(NativeActivityUpdateContext)	Updates the instance of NativeActivity. (Inherited from NativeActivity)