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//----------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
//----------------------------------------------------------------
namespace System.Activities.Expressions
{
using System.Activities.Validation;
using System.Collections.ObjectModel;
using System.Linq.Expressions;
using System.Runtime;
static class UnaryExpressionHelper
{
public static void OnGetArguments<TOperand>(CodeActivityMetadata metadata, InArgument<TOperand> operand)
{
RuntimeArgument operandArgument = new RuntimeArgument("Operand", typeof(TOperand), ArgumentDirection.In, true);
metadata.Bind(operand, operandArgument);
metadata.SetArgumentsCollection(
new Collection<RuntimeArgument>
{
operandArgument
});
}
public static bool TryGenerateLinqDelegate<TOperand, TResult>(ExpressionType operatorType, out Func<TOperand, TResult> operation, out ValidationError validationError)
{
operation = null;
validationError = null;
ParameterExpression operandParameter = Expression.Parameter(typeof(TOperand), "operand");
try
{
UnaryExpression unaryExpression = Expression.MakeUnary(operatorType, operandParameter, typeof(TResult));
Expression expressionToCompile = OperatorPermissionHelper.InjectReflectionPermissionIfNecessary(unaryExpression.Method, unaryExpression);
Expression<Func<TOperand, TResult>> lambdaExpression = Expression.Lambda<Func<TOperand, TResult>>(expressionToCompile, operandParameter);
operation = lambdaExpression.Compile();
return true;
}
catch (Exception e)
{
if (Fx.IsFatal(e))
{
throw;
}
validationError = new ValidationError(e.Message);
return false;
}
}
}
}
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