Masuit.Tools/Masuit.Tools.Core/Linq/LinqExtension.cs

using System;
using System.Linq.Expressions;

namespace Masuit.Tools.Core.Linq
{
    public static class LinqExtension
    {
        public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> left, Expression<Func<T, bool>> right)
        {
            var dateExpr = Expression.Parameter(typeof(T));
            var parameterReplacer = new ParameterReplacer(dateExpr);
            var leftwhere = parameterReplacer.Replace(left.Body);
            var rightwhere = parameterReplacer.Replace(right.Body);
            var body = Expression.And(leftwhere, rightwhere);
            return Expression.Lambda<Func<T, bool>>(body, dateExpr);
        }

        public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> left, Expression<Func<T, bool>> right)
        {
            var dateExpr = Expression.Parameter(typeof(T));
            var parameterReplacer = new ParameterReplacer(dateExpr);
            var leftwhere = parameterReplacer.Replace(left.Body);
            var rightwhere = parameterReplacer.Replace(right.Body);
            var body = Expression.Or(leftwhere, rightwhere);
            return Expression.Lambda<Func<T, bool>>(body, dateExpr);
        }
    }
}