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