Question

我被困在一个简单的设想中。我有一个 List<string> 对象, 其所有项目都有 :

item_1_2_generatedGUID //generatedGUID is Guid.NewGuid()

but there may be much more numbers item_1_2_3_4_5_generatedGUID etc

现在,我想知道该如何改变这个循环到 LINQ 查询中。有什么想法吗?

  string one = "1"; //an exaplme
  string two = "2"; //an exaplme

  foreach (var item in myStringsList)
  {
      string[] splitted = item.Split(new char[] {  _  },
                                     StringSplitOptions.RemoveEmptyEntries);

      if(splitted.Length >= 3)
      {
          if(splitted[1] == one && splitted[2] == two)
          {
              resultList.Add(item);
          }
      }
  }

Answer 1

var result = from s in lst 
             let spl = s.Split( _ )
             where spl.Length >= 3 && spl[1] = one  && spl[2] == two
             select s;

Answer 2

尝试此 :

var query = from item in myStringsList
            let splitted = item.Split(new[] {  _  }, SSO.RemoveEmptyEntries)
            where splitted.Length >= 3
            where splitted[1] == one && splitted[2] == two
            select item;

var resultList = query.ToList();

Answer 3

这是一种不同的做法:

var items = myStringsList.
            Where(x => x.Substring(x.IndexOf("_")).StartsWith(one+"_"+two+"_"));

您可能需要在索引中添加一个+1, 但我不确定。

它的作用是:

Removes the first item (that s the substring for). In your example, it should be "1_2_3_4_5_generatedGUID"
Checks the string starts with what you are expecting. In your example: 1_2_

Answer 4

< 加固 > 编辑后: 在第一个“ 位置” 时添加任何文件的样式

var result = items.Where(i => Regex.IsMatch(i, "^[^_]_1_2_"));

友情链接