在项目列表中查找索引 [英] find index in item list

问题描述

我有一个包含2列的表，第一个名字，第二个expsup ，还有一个像这些：

i have a table with 2 colum , first name , second expsup , and also ia have a transactions like these :

a: 0.2,b: 0.3,c: 0.1
a: 0.4,c: 0.5

i可以拆分名称和浮点数（ expsup ）并将它们放在变量（item.Name和item.Expsup）上，就像这样

a = item.Name 0.4 = item.Expsup

现在我想将它们插入表中并将所有expsups加在一起。（对于例子为第一个a：0.2读取并插入表中，对于第二个事务a：0.4将读取0.2和0.4加在一起）

i could split name and the float number (expsup)and put them on variable (item.Name and item.Expsup) like this
"a = item.Name 0.4=item.Expsup"
now i want to insert them in table and all expsups add together.(for example for first one a: 0.2 read and insert in table , for second transaction that a: 0.4 will read 0.2 and 0.4 be add together)

private void AddItem(Item item)
{
           var list = this.Items.Where(x => x.Name == item.Name).ToList();
           if (list.Count == 0)  //  item doesnot exist in table
         {
               item.count = 1               
               item.Name = item.Name;
               Expsup = item.Expsup;
               this.Items.Add(item);
           }
           else if (list.Count == 1) //item exist in table
           {

现在我必须在表中搜索以找到与当前项目具有相同名称的项目，然后挖掘项目的expsup然后添加它们（例如a：0.2插入表格和现在a：0.4读取，我们应该在表中搜索firs以找到最后的expsup并现在添加新的expsup）

now here i have to search in table to find item with same name with current item and then mining the item's expsup and then add them (for example a: 0.2 inserted in table and now a: 0.4 read , we should firs search in table to find last expsup and now add new expsup to it)

推荐答案

as Sergey Alexandrovich Kryukov [ ^ ]在这个论坛上多次提到： 你应该工作数据，而不是字符串表示！



为了能够得到项目的总和，你必须定义课程如下：

As Sergey Alexandrovich Kryukov[^] had mentioned several times on this forum: you should work on data, not on its string representation!

To be able to get the sum of items, you have to define class as follow:

public class Item
{
    private int index = 0;
    private string name = string.Empty;
    private double expsup = 0.0;

    public Item(int _index, string _name, double _expsup)
    {
        index= _index;
        name = _name;
        expsup = _expsup;
    }

    public int Index
    {
        get{return index;}
        set{index = value;}
    }
    public string Name
    {
        get{return name;}
        set{name = value;}
    }

    public double Expsup
    {
        get{return expsup;}
        set{expsup = value;}
    }

}

用法：

Usage:

List<string> stupiddata= new List<string>{"a: 0.2,b: 0.3,c: 0.1", "a: 0.4,c: 0.5"};

List<Item> items = stupiddata
    .SelectMany(it=>it.Split(','))
    .Select((it, ind)=>new Item
        (
            ind++,
            it.Split(':')[0],
            Convert.ToDouble(it.Split(':')[1].Trim(), new System.Globalization.CultureInfo("en-US"))
        )).ToList();

var sumOfItems = items.GroupBy(it=>it.Name)
    .Select(grp=>new
        {
            ItemName = grp.Key,
            ItemSum = grp.Sum(a=>a.Expsup)
        });

	foreach(var v in sumOfItems)
	{
		Console.WriteLine("{0} : {1}", v.ItemName, v.ItemSum);	
	}

结果：

Result:

a : 0.6
b : 0.3
c : 0.6

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