Question

我希望使用泛型来从列表中获得总和，如

List<Name,Value> test=new List<Name,Value>();
E.g list contain these element
test.Add(One,5);
test.Add(Second,5);
test.Add(Third,5);
test.Add(One,5);
test.Add(One,5);
test.Add(Second,5);

最终想要获得价值具有一个名称的元素包含值15 带有第二个名称的元素包含值10 具有第三名称的元素包含值5

我不想手动迭代每个元素。这不是一个确切的语法，它是一个想法。

Answer 1

你需要这样的东西吗？

            List<KeyValuePair<string, int>> test = new List<KeyValuePair<string, int>>();
test.Add(new KeyValuePair<string,int>("One",5));
test.Add(new KeyValuePair<string,int>("Second",5));
test.Add(new KeyValuePair<string,int>("Third",5));
test.Add(new KeyValuePair<string,int>("One",5));
test.Add(new KeyValuePair<string,int>("One",5));
test.Add(new KeyValuePair<string,int>("Second",5));

var result = test.GroupBy(r => r.Key).Select(r => new KeyValuePair<string, int>(r.Key, r.Sum(p => p.Value))).ToList();

Answer 2

尝试：

List<KeyValuePair<string, int>> test = new List<KeyValuePair<string, int>>();
test.Add(new KeyValuePair<string,int>("One",5));
test.Add(new KeyValuePair<string,int>("Second",5));
test.Add(new KeyValuePair<string,int>("Third",5));
test.Add(new KeyValuePair<string,int>("One",5));
test.Add(new KeyValuePair<string,int>("One",5));
test.Add(new KeyValuePair<string,int>("Second",5));

var sum = test.Where( x => x.Key == "One" ).Sum( y => y.Value );

从列表中获取相同元素的总和

2 个答案: