43 lines
1.3 KiB
C#
43 lines
1.3 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Diagnostics.CodeAnalysis;
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using System.Linq;
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using System.Text;
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using System.Threading.Tasks;
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namespace Yi.Framework.Infrastructure.Helper
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{
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public class Compare<T, C> : IEqualityComparer<T>
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{
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private Func<T, C> _getField;
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public Compare(Func<T, C> getfield)
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{
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_getField = getfield;
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}
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public bool Equals(T? x, T? y)
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{
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return EqualityComparer<C>.Default.Equals(_getField(x!), _getField(y!));
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}
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public int GetHashCode(T obj)
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{
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return EqualityComparer<C>.Default.GetHashCode(_getField(obj)!);
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}
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}
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public static class DistinctHelper
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{
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/// <summary>
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/// 自定义Distinct扩展方法
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/// </summary>
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/// <typeparam name="T">要去重的对象类</typeparam>
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/// <typeparam name="C">自定义去重的字段类型</typeparam>
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/// <param name="source">要去重的对象</param>
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/// <param name="getfield">获取自定义去重字段的委托</param>
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/// <returns></returns>
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public static IEnumerable<T> DistinctNew<T, C>(this IEnumerable<T> source, Func<T, C> getfield)
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{
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return source.Distinct(new Compare<T, C>(getfield));
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}
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}
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}
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