ภาพรวม
คุณสมบัติ Count ของ OrderedDictionary คืนจำนวนคู่คีย์/ค่าที่มีอยู่
ตัวอย่าง 1: เพิ่ม 6 รายการแล้ว Clear
using System;
using System.Collections;
using System.Collections.Specialized;
public class Demo {
public static void Main() {
OrderedDictionary dict = new OrderedDictionary();
dict.Add("A", "Home Appliances");
dict.Add("B", "Electronics");
dict.Add("C", "Smart Wearables");
dict.Add("D", "Pet Supplies");
dict.Add("E", "Clothing");
dict.Add("F", "Footwear");
Console.WriteLine("OrderedDictionary elements...");
foreach (DictionaryEntry d in dict) {
Console.WriteLine(d.Key + " " + d.Value);
}
Console.WriteLine("Count of elements in OrderedDictionary = " + dict.Count);
dict.Clear();
Console.WriteLine("Count of elements in OrderedDictionary (Updated)= " + dict.Count);
}
}
ผลลัพธ์ตัวอย่าง 1
OrderedDictionary elements... A Home Appliances B Electronics C Smart Wearables D Pet Supplies E Clothing F Footwear Count of elements in OrderedDictionary = 6 Count of elements in OrderedDictionary (Updated)= 0
ตัวอย่าง 2: เปรียบเทียบสอง Dictionary
using System;
using System.Collections;
using System.Collections.Specialized;
public class Demo {
public static void Main() {
OrderedDictionary dict1 = new OrderedDictionary();
dict1.Add("A", "John");
dict1.Add("B", "Andy");
dict1.Add("C", "Jacob");
dict1.Add("D", "Kevin");
dict1.Add("E", "Gary");
dict1.Add("F", "Nathan");
dict1.Add("G", "Kevin");
dict1.Add("H", "Ryan");
Console.WriteLine("OrderedDictionary1 elements...");
foreach (DictionaryEntry d in dict1) {
Console.WriteLine(d.Key + " " + d.Value);
}
Console.WriteLine("Count of key-value pairs in OrderedDictionary1 = " + dict1.Count);
OrderedDictionary dict2 = new OrderedDictionary();
dict2.Add("1", "One");
dict2.Add("2", "Two");
dict2.Add("3", "Three");
dict2.Add("4", "Four");
dict2.Add("5", "Five");
dict2.Add("6", "Six");
Console.WriteLine("\nOrderedDictionary2 elements...");
foreach (DictionaryEntry d in dict2) {
Console.WriteLine(d.Key + " " + d.Value);
}
Console.WriteLine("Count of key-value pairs in OrderedDictionary2 = " + dict2.Count);
Console.WriteLine("\nIs OrderedDictionary1 equal to OrderedDictionary2? = " + (dict1.Equals(dict2)));
OrderedDictionary orderedDict = dict2.AsReadOnly();
Console.WriteLine("Is OrderedDictionary read-only? = " + orderedDict.IsReadOnly);
}
}
ผลลัพธ์ตัวอย่าง 2
OrderedDictionary1 elements... A John B Andy C Jacob D Kevin E Gary F Nathan G Kevin H Ryan Count of key-value pairs in OrderedDictionary1 = 8 OrderedDictionary2 elements... 1 One 2 Two 3 Three 4 Four 5 Five 6 Six Count of key-value pairs in OrderedDictionary2 = 6 Is OrderedDictionary1 equal to OrderedDictionary2? = False Is OrderedDictionary read-only? = True
สรุป
Count– จำนวนคู่คีย์/ค่าAsReadOnly()– คืน wrapper แบบอ่านอย่างเดียว- รักษาลำดับการเพิ่ม (insertion order)
