C# 比较两个类似于Diff工具的类对象列表
问题已提出 我的要求是编写一个类似于diff工具的程序。是的,有相当多的库和开源代码实现了这一目的,但我想编写自己的比较器 这是起点。我有一个名为DataItem的类,它如下所示:C# 比较两个类似于Diff工具的类对象列表,c#,linq,diff,iequalitycomparer,compareobject,C#,Linq,Diff,Iequalitycomparer,Compareobject,问题已提出 我的要求是编写一个类似于diff工具的程序。是的,有相当多的库和开源代码实现了这一目的,但我想编写自己的比较器 这是起点。我有一个名为DataItem的类,它如下所示: public class DataItem { public DataItem() { } public DataItem(string d, string v) { Data = d; Value = v; } public string Data { get; set; } pu
public class DataItem
{
public DataItem() { }
public DataItem(string d, string v) { Data = d; Value = v; }
public string Data { get; set; }
public string Value { get; set; }
}
Added Items:
EEE,9
Removed Items:
CCC,3
GGG,3
Diff Items:
BBB
FFF
public class DiffItem
{
public DiffItem() { }
public DiffItem(string data, string type, string pre, string post) { Data = data; DiffType = type; PreVal = pre; PostVal = post; }
public string Data { get; set; }
public string DiffType { get; set; } // DiffType = Add/Remove/Diff
public string PreVal { get; set; } // preList value corresponding to Data item
public string PostVal { get; set; } // postList value corresponding to Data item
}
我有两个这些类对象的列表,让我们称它们为PRE和POST,并取一些示例值,如下所示数据的部分在列表中是唯一的
preList: (Data,Value)
AAA,0
BBB,1
CCC,3
DDD,4
FFF,0
GGG,3
postList: (Data,Value)
AAA,0
BBB,2
DDD,4
EEE,9
FFF,3
将PRE视为原始列表,并在完成一些更改后将POST视为列表。我想将两者进行比较,并将其分为三类:
public class DataItem
{
public DataItem() { }
public DataItem(string d, string v) { Data = d; Value = v; }
public string Data { get; set; }
public string Value { get; set; }
}
Added Items:
EEE,9
Removed Items:
CCC,3
GGG,3
Diff Items:
BBB
FFF
public class DiffItem
{
public DiffItem() { }
public DiffItem(string data, string type, string pre, string post) { Data = data; DiffType = type; PreVal = pre; PostVal = post; }
public string Data { get; set; }
public string DiffType { get; set; } // DiffType = Add/Remove/Diff
public string PreVal { get; set; } // preList value corresponding to Data item
public string PostVal { get; set; } // postList value corresponding to Data item
}
我还有另一个DiffItem类,我想把最终结果放在它的对象上。DiffItem如下所示:
public class DataItem
{
public DataItem() { }
public DataItem(string d, string v) { Data = d; Value = v; }
public string Data { get; set; }
public string Value { get; set; }
}
Added Items:
EEE,9
Removed Items:
CCC,3
GGG,3
Diff Items:
BBB
FFF
public class DiffItem
{
public DiffItem() { }
public DiffItem(string data, string type, string pre, string post) { Data = data; DiffType = type; PreVal = pre; PostVal = post; }
public string Data { get; set; }
public string DiffType { get; set; } // DiffType = Add/Remove/Diff
public string PreVal { get; set; } // preList value corresponding to Data item
public string PostVal { get; set; } // postList value corresponding to Data item
}
为了实现这一点,我首先扩展了IEqualityComparer并编写了两个比较器:
public class DataItemComparer : IEqualityComparer<DataItem>
{
public bool Equals(DataItem x, DataItem y)
{
return (string.Equals(x.Data, y.Data) && string.Equals(x.Value, y.Value));
}
public int GetHashCode(DataItem obj)
{
return obj.Data.GetHashCode();
}
}
public class DataItemDataComparer : IEqualityComparer<DataItem>
{
public bool Equals(DataItem x, DataItem y)
{
return string.Equals(x.Data, y.Data);
}
public int GetHashCode(DataItem obj)
{
return obj.Data.GetHashCode();
}
}
公共类DataItemComparer:IEqualityComparer
{
公共布尔等于(数据项x、数据项y)
{
返回(string.Equals(x.Data,y.Data)&&string.Equals(x.Value,y.Value));
}
public int GetHashCode(DataItem obj)
{
返回obj.Data.GetHashCode();
}
}
公共类DataItemDataComparer:IEqualityComparer
{
公共布尔等于(数据项x、数据项y)
{
返回字符串.Equals(x.Data,y.Data);
}
public int GetHashCode(DataItem obj)
{
返回obj.Data.GetHashCode();
}
}
然后使用Except()和Intersect()方法,如下所示:
static void DoDiff()
{
diffList = new List<DiffItem>();
IEnumerable<DataItem> preOnly = preList.Except(postList, new DataItemComparer());
IEnumerable<DataItem> postOnly = postList.Except(preList, new DataItemComparer());
IEnumerable<DataItem> common = postList.Intersect(preList, new DataItemComparer());
IEnumerable<DataItem> added = postOnly.Except(preOnly, new DataItemDataComparer());
IEnumerable<DataItem> removed = preOnly.Except(postOnly, new DataItemDataComparer());
IEnumerable<DataItem> diffPre = preOnly.Intersect(postOnly, new DataItemDataComparer());
IEnumerable<DataItem> diffPost = postOnly.Intersect(preOnly, new DataItemDataComparer());
foreach (DataItem add in added)
{
diffList.Add(new DiffItem(add.Data, "Add", null, add.Value));
}
foreach (DataItem rem in removed)
{
diffList.Add(new DiffItem(rem.Data, "Remove", rem.Value, null));
}
foreach (DataItem pre in diffPre)
{
DataItem post = diffPost.First(x => x.Data == pre.Data);
diffList.Add(new DiffItem(pre.Data, "Diff", pre.Value, post.Value));
}
}
static void DoDiff()
{
diffList=新列表();
IEnumerable preOnly=preList.Except(postList,new DataItemComparer());
IEnumerable postOnly=postList.Except(preList,new DataItemComparer());
IEnumerable common=postList.Intersect(预列表,新的DataItemComparer());
IEnumerable added=postOnly.Except(仅限新的DataItemDataComparer());
IEnumerable removed=preOnly.Except(postOnly,new DataItemDataComparer());
IEnumerable diffPre=preOnly.Intersect(postOnly,new DataItemDataComparer());
IEnumerable diffPost=postOnly.Intersect(仅限新的DataItemDataComparer());
foreach(已添加DataItem外接程序)
{
Add(新的DiffItem(Add.Data,“Add”,null,Add.Value));
}
foreach(删除数据项rem)
{
添加(新的DiffItem(rem.Data,“Remove”,rem.Value,null));
}
foreach(diffPre中的DataItem pre)
{
DataItem post=diffPost.First(x=>x.Data==pre.Data);
添加(新的DiffItem(pre.Data,“Diff”、pre.Value、post.Value));
}
}
这确实有效,并且完成了工作。但我想知道是否有更好的方法来做到这一点。请注意,我在“更好”一词周围加了引号,因为我没有一个合适的定义来说明什么能让它更好。也许有一种方法可以在不使用那么多“foreach”循环和使用Except()和Intersetc()的情况下完成这项工作,因为我可以想象在Linq后面有相当多的迭代正在进行
简单地说,是否有一个更干净的代码,我可以写这个?我的提问主要是出于学术兴趣和扩大我的知识面。我认为您不需要您的IEQuality Comparer:
var added = from a in postList
where !preList.Any(b => b.Data == a.Data)
select new DiffItem(a.Data, "Add", null, a.Value);
var removed = from b in preList
where !postList.Any(a => a.Data == b.Data)
select new DiffItem(b.Data, "Remove", b.Value, null);
var diff = from b in preList
join a in postList on b.Data equals a.Data
where b.Value != a.Value
select new DiffItem(b.Data, "Diff", b.Data, a.Data);
var diffList = added.ToList();
diffList.AddRange(removed);
diffList.AddRange(diff);
这将是更好地张贴到。谢谢你的建议!是否可以将此移到那个里,或者我应该删除并发布到那个里?我投票将此问题作为离题题结束,因为我已将其移到代码审阅站点。