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