//构造Lambda语句
private static Expression<Func<TElement, bool>> BuildWhereInExpression<TElement, TValue>(Expression<Func<TElement, TValue>> propertySelector, IEnumerable<TValue> values) { ParameterExpression p = propertySelector.Parameters.Single(); if (!values.Any()) return e => false; var equals = values.Select(value => (Expression)Expression.Equal(propertySelector.Body, Expression.Constant(value, typeof(TValue)))); var body = equals.Aggregate<Expression>((accumulate, equal) => Expression.Or(accumulate, equal)); return Expression.Lambda<Func<TElement, bool>>(body, p); }