private static Expression CreateValueExpression(Type targetType, object value, CultureInfo culture)
{
if (targetType != typeof(string) && (!targetType.GetTypeInfo().IsValueType || TypeExtensions.IsNullableType(targetType)) &&
string.Compare(value as string, "null", StringComparison.OrdinalIgnoreCase) == 0)
{
value = null;
}
if (value != null)
{
Type nonNullableType = TypeExtensions.GetNonNullableType(targetType);
if (value.GetType() != nonNullableType)
{
if (nonNullableType.GetTypeInfo().IsEnum)
{
value = Enum.Parse(nonNullableType, value.ToString(), true);
}
else if (nonNullableType == typeof(Guid))
{
value = new Guid(value.ToString());
}
else if (value is IConvertible)
{
value = Convert.ChangeType(value, nonNullableType, culture);
}
}
}
return(CreateConstantExpression(value));
}
protected virtual Expression CreateMemberExpression()
{
Type memberType = FilterDescriptor.MemberType;
MemberAccessExpressionBuilderBase expressionBuilderBase =
ExpressionBuilderFactory.MemberAccess(ParameterExpression.Type, memberType, FilterDescriptor.Member);
expressionBuilderBase.Options.CopyFrom(Options);
expressionBuilderBase.ParameterExpression = ParameterExpression;
Expression expression = expressionBuilderBase.CreateMemberAccessExpression();
if (memberType != null &&
TypeExtensions.GetNonNullableType(expression.Type) != TypeExtensions.GetNonNullableType(memberType))
{
expression = Expression.Convert(expression, memberType);
}
return(expression);
}