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C# BinaryExpression.IsLeafType方法代码示例

本文整理汇总了C#中System.Linq.Expressions.BinaryExpression.IsLeafType方法的典型用法代码示例。如果您正苦于以下问题:C# BinaryExpression.IsLeafType方法的具体用法?C# BinaryExpression.IsLeafType怎么用?C# BinaryExpression.IsLeafType使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在System.Linq.Expressions.BinaryExpression的用法示例。


在下文中一共展示了BinaryExpression.IsLeafType方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。

示例1: VisitBinary

        /// <summary>
        /// Deal with a special case for an index redirection where we are looking for
        /// an integer or some simply type. There is only one very special case where this
        /// shows up. Unlikely to be used by physics, actually. :-) The second case we
        /// handle is dealing with != for two object compares.
        /// </summary>
        /// <param name="expression"></param>
        /// <returns></returns>
        protected override Expression VisitBinary(BinaryExpression expression)
        {
            //
            // If we are comparing a "new" against a null, then we don't support that.
            //

            if (expression.Left.IsNull() || expression.Right.IsNull())
            {
                Expression nonNull = expression.Left.IsNull() ? expression.Right : expression.Left;
                if (nonNull.NodeType == ExpressionType.New)
                {
                    throw new InvalidOperationException(string.Format("Doing a null comparison to a temporary object created in the query is very likely to generate incorrect code - not supported ({0})", expression.ToString()));
                }
            }

            // If this is an array index, then...
            if (expression.NodeType == ExpressionType.ArrayIndex && expression.IsLeafType())
            {
                var rootExpr = expression.Left as MemberExpression;
                if (rootExpr != null)
                {
                    return Expression.ArrayIndex(VisitExpressionImplemented(rootExpr), expression.Right);
                }
            }

            // If this is a comparison, and these are objects that have indicies (in whatever we are looping through)...
            if (expression.NodeType == ExpressionType.Equal || expression.NodeType == ExpressionType.NotEqual)
            {
                // Are we pointing to something we can deal with?
                var indexLeft = ExtractIndexReference(expression.Left);
                if (indexLeft != null)
                {
                    var indexRight = ExtractIndexReference(expression.Right);
                    if (indexRight != null)
                    {
                        if (expression.NodeType == ExpressionType.NotEqual)
                        {
                            return Expression.NotEqual(indexLeft, indexRight);
                        } else
                        {
                            return Expression.Equal(indexLeft, indexRight);
                        }
                    }
                }
            }

            return base.VisitBinary(expression);
        }
开发者ID:gordonwatts,项目名称:LINQtoROOT,代码行数:56,代码来源:TranslatingExpressionVisitor.cs


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