ValueTypeIndexerReference<TOperand,TItem> Klass

Definition

generic <typename TOperand, typename TItem>
public ref class ValueTypeIndexerReference sealed : System::Activities::CodeActivity<System::Activities::Location<TItem> ^>

[System.Windows.Markup.ContentProperty("Indices")]
public sealed class ValueTypeIndexerReference<TOperand,TItem> : System.Activities.CodeActivity<System.Activities.Location<TItem>>

[<System.Windows.Markup.ContentProperty("Indices")>]
type ValueTypeIndexerReference<'Operand, 'Item> = class
    inherit CodeActivity<Location<'Item>>

Public NotInheritable Class ValueTypeIndexerReference(Of TOperand, TItem)
Inherits CodeActivity(Of Location(Of TItem))

Typparametrar

Arv

Object

Activity

ActivityWithResult

Activity<TResult>

CodeActivity<Location<TItem>>

ValueTypeIndexerReference<TOperand,TItem>

Attribut

ContentPropertyAttribute

Exempel

I följande kodexempel används ValueTypeIndexerReference<TOperand,TItem> i en Assign aktivitet för att tilldela ett string värde till elementet struct vid index 1 och skriver ut elementvärdet till konsolen. Aktiviteten Assign motsvarar följande instruktion när du använder det struct definierade i följande exempel: myStructVariable[1] = "Hello";.

    // Define a struct with an indexer.
    struct StructWithIndexer
    {
        string val;
        public string this[int index]
        {
            get { return val; }
            set { val = value; }
        }
    }

    public static void ValueTypeIndexerReferenceSample()
    {
        // Create a variable of type StructWithIndexer to store the element.
        var swivar = new Variable<StructWithIndexer>("swivar", new StructWithIndexer());

        // Create the top-level activity to be invoked later.
        Activity myActivity = new Sequence
        {
            Variables = { swivar },
            Activities =
            {
                // Create an Assign activity with an element at index 1.
                new Assign<string>
                {
                    To = new ValueTypeIndexerReference<StructWithIndexer, string>
                    {
                        OperandLocation = swivar,
                        Indices = { new InArgument<int>(1) },
                    },
                    // Assign a string literal to the element at index 1.
                    Value = "Hello",
                },
                new WriteLine()
                {
                    Text = ExpressionServices.Convert<string>(ctx => swivar.Get(ctx)[1]),
                }
            }
        };

        // Invoke the Sequence activity.
        WorkflowInvoker.Invoke(myActivity);
}