做一个更好的方法来包装类中的多个列表/字典，并循环键和值 [英] Make a better approach to wrap multiple lists/ dictionary inside class and looping key and value

问题描述

我将此代码用于关联数组

I made this code for associative array

var data = new Dictionary<int,Dictionary<string,List<int>>>() {
   {100, new Dictionary<string, List<int>>() {
      {"first", new List<int>() {4, 24, 5, 0}},
      {"second", new List<int>() {42, 58, 23, 8}} //TODO - add third, fourth etc.
   }},
   {500, new Dictionary<string, List<int>>() {
      {"first", new List<int>() {4, 24, 5, 0}},
      {"second", new List<int>() {42, 58, 23, 8}} //TODO - add third, fourth etc.
   }}
}

之后，我觉得这在C＃中感觉非常不直观：将多个列表/字典包含在一起是不是最优雅的解决方案。

After that I thought that This feels very unintuitive in C#: Wrapping multiple Lists/Dictionarys inside each other isn't the most elegant solution.

所以我认为这可能是一个更好的方法来将这个结构包装在类中：

So I made it might be a better approach to wrap this construct inside classes:

public class DataContainer {
      public int Index { get; set; }
      public DataValue MyValue { get; set; }`enter code here`
    }

    public class DataValue {
      public string Name { get; set; }
      public List<int> IntegerValues { get; set; }
    }

我在主要的

var data = new List<DataContainer>()
            {
                new DataContainer{index = 100 , DataValue = new DataValue
                {name = "first", IntegerValues = {5,4,5,5}}},
                 new DataContainer{index = 100 , DataValue = new DataValue
                {name = "second", IntegerValues = {10,45,5,65}}},
                 new DataContainer{index = 100 , DataValue = new DataValue
                {name = "third", IntegerValues = {10,45,5,65}}}


            };

但我有一个例外，我尝试修复它，但我再次收到异常

but i got an exception , i try to fix it but i get an exception again

System.NullReferenceException was unhandled
  HResult=-2147467261
  Message=Object reference not set to an instance of an object.
  Source=FalaqHijriyyah
  StackTrace:
       at FalaqHijriyyah.Program.Main(String[] args) in d:\Console\FalaqHijriyyah\FalaqHijriyyah\Program.cs:line 13
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

如何做到这一点我想循环该键和值？

How to do that and i want to loop that key and value ?

推荐答案

NullReference 因为从未创建列表< int> IntegerValues 。

您可以更改代码：

  var data = new List<DataContainer>()
        {
            new DataContainer{Index = 100 , MyValue = new DataValue
            {Name = "first", IntegerValues = new List<int>{5,4,5,5}}},
             new DataContainer{Index = 100 , MyValue = new DataValue
            {Name = "second", IntegerValues = new List<int>{10,45,5,65}}},
             new DataContainer{Index = 100 , MyValue = new DataValue
            {Name = "third", IntegerValues = new List<int>{10,45,5,65}}}
        };

IntegerValues 未正确创建：indestead {5,4,5,5} ，使用新列表< int> ...

IntegerValues is not properly created: indestead of {5,4,5,5}, use new List<int> ...

您还可以保留语法并使用静态对象初始化器： / p>

You could also keep your syntax and use a static object initializer:

public class DataValue {
  public string Name { get; set; }
  public List<int> IntegerValues = new List<int>();
}

那么你可以创建 DataValue 像这样：

then you can create DataValue like this:

new DataValue {Name = "first", IntegerValues = {5,4,5,5}}

---

循环整数（或其他）这样简单：

---

Looping over the Integers (or anything else) is as easy as that:

        foreach(DataContainer dataContainer in data) {
            foreach (int intValue in dataContainer.MyValue.IntegerValues) {
                Console.WriteLine(intValue);
            }
        }

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