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//-----------------------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
//-----------------------------------------------------------------------------
namespace System.Activities.Expressions
{
using System.Activities.Statements;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.Serialization;
public sealed class ArrayItemReference<TItem> : CodeActivity<Location<TItem>>
{
public ArrayItemReference()
: base()
{
}
[RequiredArgument]
[DefaultValue(null)]
public InArgument<TItem[]> Array
{
get;
set;
}
[RequiredArgument]
[DefaultValue(null)]
public InArgument<int> Index
{
get;
set;
}
protected override void CacheMetadata(CodeActivityMetadata metadata)
{
RuntimeArgument arrayArgument = new RuntimeArgument("Array", typeof(TItem[]), ArgumentDirection.In, true);
metadata.Bind(this.Array, arrayArgument);
RuntimeArgument indexArgument = new RuntimeArgument("Index", typeof(int), ArgumentDirection.In, true);
metadata.Bind(this.Index, indexArgument);
RuntimeArgument resultArgument = new RuntimeArgument("Result", typeof(Location<TItem>), ArgumentDirection.Out);
metadata.Bind(this.Result, resultArgument);
metadata.SetArgumentsCollection(
new Collection<RuntimeArgument>
{
arrayArgument,
indexArgument,
resultArgument
});
}
protected override Location<TItem> Execute(CodeActivityContext context)
{
TItem[] items = this.Array.Get(context);
if (items == null)
{
throw FxTrace.Exception.AsError(new InvalidOperationException(SR.MemberCannotBeNull("Array", this.GetType().Name, this.DisplayName)));
}
int itemIndex = this.Index.Get(context);
return new ArrayLocation(items, itemIndex);
}
[DataContract]
internal class ArrayLocation : Location<TItem>
{
TItem[] array;
int index;
public ArrayLocation(TItem[] array, int index)
: base()
{
this.array = array;
this.index = index;
}
public override TItem Value
{
get
{
return this.array[this.index];
}
set
{
this.array[this.index] = value;
}
}
[DataMember(Name = "array")]
internal TItem[] SerializedArray
{
get { return this.array; }
set { this.array = value; }
}
[DataMember(EmitDefaultValue = false, Name = "index")]
internal int SerializedIndex
{
get { return this.index; }
set { this.index = value; }
}
}
}
}
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