Linq 选择新对象 [英] Linq select to new object

问题描述

我有一个 linq 查询

I have a linq query

var x = (from t in types select t).GroupBy(g =>g.Type)

按类型对对象进行分组，因此我希望有一个包含所有分组对象及其计数的新对象.像这样:

which groups objects by their type, as a result I want to have single new object containing all of the grouped objects and their count. Something like this:

type1, 30    
type2, 43    
type3, 72

更清楚:分组结果应该在一个对象中，而不是每个项目类型的对象

to be more clear: grouping results should be in one object not an object per item type

推荐答案

阅读:101 个 LINQ 示例，其中 LINQ - Grouping Operators 来自 Microsoft MSDN 站点

Read : 101 LINQ Samples in that LINQ - Grouping Operators from Microsoft MSDN site

var x = from t in types  group t by t.Type
         into grp    
         select new { type = grp.key, count = grp.Count() };

forsingle 对象利用 stringbuilder 并将其附加到字典中或将其转换为字典

forsingle object make use of stringbuilder and append it that will do or convert this in form of dictionary

    // fordictionary 
  var x = (from t in types  group t by t.Type
     into grp    
     select new { type = grp.key, count = grp.Count() })
   .ToDictionary( t => t.type, t => t.count); 

   //for stringbuilder not sure for this 
  var x = from t in types  group t by t.Type
         into grp    
         select new { type = grp.key, count = grp.Count() };
  StringBuilder MyStringBuilder = new StringBuilder();

  foreach (var res in x)
  {
       //: is separator between to object
       MyStringBuilder.Append(result.Type +" , "+ result.Count + " : ");
  }
  Console.WriteLine(MyStringBuilder.ToString());   

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