96 lines
3.2 KiB
C#
96 lines
3.2 KiB
C#
|
//----------------------------------------------------------------
|
|||
|
|
// Copyright (c) Microsoft Corporation. All rights reserved.
|
|||
|
|
//----------------------------------------------------------------
|
|||
|
|
|
|||
|
|
namespace System.Activities.Expressions
|
|||
|
|
{
|
|||
|
|
using System.Activities;
|
|||
|
|
using System.Activities.Statements;
|
|||
|
|
using System.Activities.Validation;
|
|||
|
|
using System.Collections.Generic;
|
|||
|
|
using System.ComponentModel;
|
|||
|
|
using System.Linq.Expressions;
|
|||
|
|
using System.Runtime;
|
|||
|
|
|
|||
|
|
public sealed class Add<TLeft, TRight, TResult> : CodeActivity<TResult>
|
|||
|
|
{
|
|||
|
|
//Lock is not needed for operationFunction here. The reason is that delegates for a given Add<TLeft, TRight, TResult> are the same.
|
|||
|
|
//It's possible that 2 threads are assigning the operationFucntion at the same time. But it's okay because the compiled codes are the same.
|
|||
|
|
static Func<TLeft, TRight, TResult> checkedOperationFunction;
|
|||
|
|
static Func<TLeft, TRight, TResult> uncheckedOperationFunction;
|
|||
|
|
|
|||
|
|
bool checkedOperation = true;
|
|||
|
|
|
|||
|
|
[RequiredArgument]
|
|||
|
|
[DefaultValue(null)]
|
|||
|
|
public InArgument<TLeft> Left
|
|||
|
|
{
|
|||
|
|
get;
|
|||
|
|
set;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
[RequiredArgument]
|
|||
|
|
[DefaultValue(null)]
|
|||
|
|
public InArgument<TRight> Right
|
|||
|
|
{
|
|||
|
|
get;
|
|||
|
|
set;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
[DefaultValue(true)]
|
|||
|
|
public bool Checked
|
|||
|
|
{
|
|||
|
|
get { return this.checkedOperation; }
|
|||
|
|
set { this.checkedOperation = value; }
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
protected override void CacheMetadata(CodeActivityMetadata metadata)
|
|||
|
|
{
|
|||
|
|
BinaryExpressionHelper.OnGetArguments(metadata, this.Left, this.Right);
|
|||
|
|
|
|||
|
|
if (this.checkedOperation)
|
|||
|
|
{
|
|||
|
|
EnsureOperationFunction(metadata, ref checkedOperationFunction, ExpressionType.AddChecked);
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
EnsureOperationFunction(metadata, ref uncheckedOperationFunction, ExpressionType.Add);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
void EnsureOperationFunction(CodeActivityMetadata metadata,
|
|||
|
|
ref Func<TLeft, TRight, TResult> operationFunction,
|
|||
|
|
ExpressionType operatorType)
|
|||
|
|
{
|
|||
|
|
if (operationFunction == null)
|
|||
|
|
{
|
|||
|
|
ValidationError validationError;
|
|||
|
|
if (!BinaryExpressionHelper.TryGenerateLinqDelegate(
|
|||
|
|
operatorType,
|
|||
|
|
out operationFunction,
|
|||
|
|
out validationError))
|
|||
|
|
{
|
|||
|
|
metadata.AddValidationError(validationError);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
protected override TResult Execute(CodeActivityContext context)
|
|||
|
|
{
|
|||
|
|
TLeft leftValue = this.Left.Get(context);
|
|||
|
|
TRight rightValue = this.Right.Get(context);
|
|||
|
|
|
|||
|
|
//if user changed Checked flag between Open and Execution,
|
|||
|
|
//a NRE may be thrown and that's by design
|
|||
|
|
if (this.checkedOperation)
|
|||
|
|
{
|
|||
|
|
return checkedOperationFunction(leftValue, rightValue);
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
return uncheckedOperationFunction(leftValue, rightValue);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|