LINQ副本(un)标记方法

本文关键字：方法 un 副本 LINQ | 更新日期: 2023-09-27 18:17:16

我已经阅读了一些检查dup的方法，但在这种情况下，我需要一个属性(IsDup)，这很容易设置，但由于两个项目(相等的对象)都是IsDup，一旦两个项目中的一个被改变，就很难从两者中删除它。

这是我的示例代码，但我挣扎与组和计数的东西。基本上，我想查找任何组(基于相等)为1，这意味着它的伙伴(当前)被更改，它的IsDup现在为false，所以我需要将此项更改为false。

我认为这里的逻辑是合理的，我只是在LINQ方面挣扎

public class Test
{
    public static void Main()
    {

        //current was a dup of the first item, which is why its set to true
        var current = new CustOb(){ prop1 = "prop1C", prop2 = "prop2C", IsDup=true};
        var list = new List<CustOb>();
        list.Add(new CustOb(){ prop1 = "prop1A", prop2 = "prop2A", IsDup=true});  //was a dup with current
        list.Add(new CustOb(){ prop1 = "prop1B", prop2 = "prop2B", IsDup=false});
        list.Add(new CustOb(){ prop1 = "imadup", prop2 = "dup", IsDup=true}); //this is here to make sure a real dup isnt reset
        list.Add(new CustOb(){ prop1 = "imadup", prop2 = "dup", IsDup=true}); //real dup
        list.Add(current);
        //code to be run on list item update
        //reset to false and recheck now that its been changed
        current.IsDup = false;
        //check to see if the 'current' item is a dup with anything in the list
        list.Where(o=>o.Equals(current)).Select(d => d.IsDup=true).ToArray();
        //look for any partners that are orphaned from this
        list.Where(o=> o.IsDup).GroupBy(x => x).Where(o=>o.Count() == 1).Select(o => o.IsDup = false);

        list.ForEach(o=>
            Console.WriteLine(o.prop1.ToString() + ", " + o.prop2.ToString() + ", " + o.IsDup.ToString())
        );
    }
}
public class CustOb
{
    public string prop1 {get;set;}
    public string prop2 {get;set;}
    public bool IsDup {get;set;}
}

最后的结果是将所有列表项1的isdup设置为false

LINQ副本(un)标记方法

经过一番折腾，我终于能够让它与下面的LINQ一起工作了。Var的名字已经被改变了，因为它是在最终的应用程序中使用的。

        //reset to false, and recheck for dups
        selectedProductConnection.IsDup = false;
        //check to see if the current item is a dup with anything in the list
        var dups = ProductConnections.Where(o => !ReferenceEquals(o, selectedProductConnection) && o.GetDupHash() == selectedProductConnection.GetDupHash());
        foreach (var pc in dups)
        {
            pc.IsDup = selectedProductConnection.IsDup = true;
        }
        //look for orphaned dup tags
        var grp = new HashSet<int>(
            ProductConnections.Where(o => o.IsDup)
                .GroupBy(o => o.GetDupHash())
                .Where(o => o.Count() == 1)
                .Select(a => a.Key));
        dups = ProductConnections.Where(x => grp.Contains(x.GetDupHash()));
        foreach (var pc in dups)
        {
            pc.IsDup = false;
        }

它可能可以稍微调整一下，但我对LINQ还是很陌生

我在我的对象上添加了一个自定义哈希，因为在我的实际用例中，它不比较整个对象，只比较某些字段。自定义散列就是

return Host.GetHashCode() ^ Product.GetHashCode() ^ Vendor.GetHashCode();
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