[英]Iterating through nested dictionary is not working in C#
我正在嘗試從嵌套字典中打印結果
var variations_hash = new Dictionary<string, Dictionary<string, List<string>>>();
但這會引發一些隨機錯誤
using System;
using System.Net;
using System.IO;
using System.Text.RegularExpressions;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
class Program
{
static void Main()
{
var variations_hash = new Dictionary<string, Dictionary<string, List<string>>>();
var variations = new Dictionary<string, List<string>>();
variations["available"] = new List<string> { "hi" };
var stores = new[] { "s", "m", "xl", "xxl", "xxxl", "v" };
string color_trans = "blue";
foreach (var sto in stores)
{
variations_hash[sto] = variations;
}
foreach(var job in variations_hash.Key())
{
foreach (var innerDict in variations_hash[key].Select(k => k.Value))
{
Console.Write(innerDict);
}
}
Console.ReadLine();
}
}
錯誤:
錯誤CS1061“字典>>”不包含“鍵”的定義,找不到可以接受類型為“字典>>”類型的第一個參數的擴展方法“鍵”(您是否缺少using指令或程序集引用?)
ConsoleApplication1 c:\\ users \\ administrator \\ documents \\ Visual Studio 2015 \\ Projects \\ ConsoleApplication1 \\ ConsoleApplication1 \\ Program.cs 29錯誤CS0103在當前上下文中不存在名稱“鍵” ConsoleApplication1 c:\\ users \\ administrator \\ documents \\ visual studio 2015 \\ Projects \\ ConsoleApplication1 \\ ConsoleApplication1 \\ Program.cs 31
警告CS0219已分配變量'color_trans',但從未使用過其值
ConsoleApplication1 c:\\ users \\ administrator \\ documents \\ Visual Studio 2015 \\ Projects \\ ConsoleApplication1 \\ ConsoleApplication1 \\ Program.cs 20
如何循環和打印嵌套字典的所有內容?
盡管您可以通過用Keys
屬性替換Key()
來解決問題,但這並不是迭代字典的最佳方法,因為您必須為循環中的每個鍵檢索對象。
迭代鍵-值對更為有效,如下所示:
foreach(var vHash in variations_hash) {
Console.WriteLine("variations_hash key = {0}", vHash.Key);
foreach (var inner in vHash.Value) {
// Print inner dictionary key followed by comma-separated list
Console.WriteLine(
"--- {0}: {1}"
, inner.Key
, string.Join(", ", inner.Value)
);
}
}
請注意,每個循環如何使您不僅可以訪問要迭代的字典的鍵(即vHash.Key
和inner.Key
),還可以訪問與該鍵關聯的值。
應該是variations_hash.Keys
另外,嵌套的字典值是List
,因此請使用SelectMany
展平結構。
foreach(var job in variations_hash.Keys)
{
foreach (var innerDict in variations_hash[key].SelectMany(k => k.Value))
{
Console.Write(innerDict);
}
}
上面的代碼可能會解決您的編譯問題並打印所有嵌套的字典值,但是要以正確的格式打印嵌套的字典,可以使用以下代碼。
foreach(var kv in variations_hash)
{
foreach (var nestedKv in kv.Values)
{
Console.Write("Key {0}- Values{1}", nestedKv.Key, string.Join(",", nestedKv.Value));
}
}
和使用Linq
var lines = variations_hash.SelectMany(x=>x.Values)
.ToList().
.ForEach(kv => Console.WriteLine("Key {0}- Values{1}", kv.Key, string.Join(",", kv.Value)));
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.