35 lines
1.4 KiB
C#
35 lines
1.4 KiB
C#
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using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Linq.Expressions;
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using System.Text;
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namespace APT.Infrastructure.Core.Extensions
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{
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public static class QueryableExtensions
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{
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public static IQueryable<T> OrderByName<T>(this IQueryable<T> queryable, string propertyName, bool desc = false)
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{
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return QueryableHelper<T>.OrderBy(queryable, propertyName, desc);
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}
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static class QueryableHelper<T>
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{
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private static Dictionary<string, LambdaExpression> cache = new Dictionary<string, LambdaExpression>();
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public static IQueryable<T> OrderBy(IQueryable<T> queryable, string propertyName, bool desc)
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{
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dynamic keySelector = GetLambdaExpression(propertyName);
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return desc ? Queryable.OrderByDescending(queryable, keySelector) : Queryable.OrderBy(queryable, keySelector);
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}
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private static LambdaExpression GetLambdaExpression(string propertyName)
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{
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if (cache.ContainsKey(propertyName)) return cache[propertyName];
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var param = Expression.Parameter(typeof(T));
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var body = Expression.Property(param, propertyName);
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var keySelector = Expression.Lambda(body, param);
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cache[propertyName] = keySelector;
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return keySelector;
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}
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}
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}
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}
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