怎么使用LINQ实现对List<List<string>>循环并拼接字符串

Question

linq

Answer 1

void Main()
{
List<List<string>> proplist = new List<List<string>>(); proplist.Add(new List<string>(){"a","b","r"});
proplist.Add(new List<string>() { "c", "d","h" });
proplist.Add(new List<string>() { "e", "f","y" });[code=csharp]

var q=from a in proplist.First()
  from b in proplist.Skip(1).First()
  from c in proplist.Skip(2).First() 
  select string.Format("{0}{1}{2}",a,b,c);
  
q.ToList().ForEach(x=>Console.WriteLine(x));
}[/code][code=csharp]void Main()
{
List<List<string>> proplist = new List<List<string>>(); proplist.Add(new List<string>(){"a","b","r"});
proplist.Add(new List<string>() { "c", "d","h" });
proplist.Add(new List<string>() { "e", "f","y" });[code=csharp]acf
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bde
bdf
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bhf
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rce
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rdf
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rhy [/code]

Answer 2

void Main()
{
List<List<string>> proplist = new List<List<string>>(); proplist.Add(new List<string>(){"a","b","r"});
proplist.Add(new List<string>() { "c", "d","h" });
proplist.Add(new List<string>() { "e", "f","y" });

var q=from a in proplist.First()
  from b in proplist.Skip(1).First()
  from c in proplist.Skip(2).First() 
  select string.Format("{0}{1}{2}",a,b,c);
  
q.ToList().ForEach(x=>Console.WriteLine(x));
}ace
acf
acy
ade
adf
ady
ahe
ahf
ahy
bce
bcf
bcy
bde
bdf
bdy
bhe
bhf
bhy
rce
rcf
rcy
rde
rdf
rdy
rhe
rhf
rhy

Answer 3

 
            var m = proplist.Aggregate(Enumerable.Repeat("", 1),
                (current, item) => current.SelectMany(n => item, (a, b) => a + b));            foreach (var item in m)
            {
                Console.WriteLine(item);
            }

Answer 4

首先,感谢版主回复啊,你这个代码有个问题啊
就是我的proplist的item是动态添加的,不是固定只有3个的

Answer 5

你的需求是对proplist的元素依次做迪卡尔积看到涉及迪卡尔积的，考虑SelectMany的带选择器版本；
看到需要依次处理的，考虑Aggregate

Answer 6

http://hi.baidu.com/qxyywy/item/49e8c7f72a019ad86325d238

Answer 7

        protected void Page_Load(object sender, EventArgs e)
        {
            List<List<string>> proplist = new List<List<string>>();            proplist.Add(new List<string>() { "a", "b", "r" });
            proplist.Add(new List<string>() { "c", "d", "h" });
            proplist.Add(new List<string>() { "e", "f", "y" });
            var a = AAAAA(proplist);
            foreach (var temp in a)
            {
                Response.Write(temp + "<br/>");
            }
        }
        public IEnumerable<string> AAAAA(List<List<string>> list)
        {
            IEnumerable<string> result = list.First();
            for (int i = 1; i < list.Count; i++)
            {
                int index = i;
                result = result.SelectMany(x => list[index].Select(y => y + x));
            }
            return result;
        }
多少个都行

Answer 8

来一个递归版本的.
List<string> res = MergeList(proplist).ToList();private IEnumerable<string> MergeList(List<List<string>> proplist)
{
    if (proplist.FirstOrDefault() == null)
        return new List<string>() { "" };
    var divs = proplist.Where(c => c != proplist.FirstOrDefault()).ToList();
    return from a in proplist.First() from b in MergeList(divs) select string.Format("{0}{1}", a, b);
}