C＃|获取包含OrderedDictionary中的键的ICollection

OrderedDictionary.Keys属性用于获取一个ICollection对象，该对象包含OrderedDictionary集合中的键。

句法：

public System.Collections.ICollection Keys { get; }

返回值：返回一个ICollection对象，该对象包含OrderedDictionary集合中的键。

下面给出了一些示例，以更好地理解实现：

范例1：

// C# code to get an ICollection
// containing the keys in OrderedDictionary
using System;
using System.Collections;
using System.Collections.Specialized;
  
class GFG {
  
    // Driver method
    public static void Main()
    {
  
        // Creating a orderedDictionary named myDict
        OrderedDictionary myDict = new OrderedDictionary();
  
        // Adding key and value in myDict
        myDict.Add("key1", "value1");
        myDict.Add("key2", "value2");
        myDict.Add("key3", "value3");
        myDict.Add("key4", "value4");
        myDict.Add("key5", "value5");
  
        // Getting an ICollection containing
        // the keys in OrderedDictionary
        ICollection keyCollection = myDict.Keys;
  
        // Creating a String array
        String[] myKeys = new String[myDict.Count];
  
        // Copying the OrderedDictionary elements to
        // a one-dimensional Array object at the
        // specified index.
        keyCollection.CopyTo(myKeys, 0);
  
        for (int i = 0; i < myDict.Count; i++) {
            Console.WriteLine(myKeys[i]);
        }
    }
}

输出：

key1
key2
key3
key4
key5

范例2：

// C# code to get an ICollection
// containing the keys in OrderedDictionary
using System;
using System.Collections;
using System.Collections.Specialized;
  
class GFG {
  
    // Driver method
    public static void Main()
    {
  
        // Creating a orderedDictionary named myDict
        OrderedDictionary myDict = new OrderedDictionary();
  
        // Adding key and value in myDict
        myDict.Add("A", "Apple");
        myDict.Add("B", "Banana");
        myDict.Add("C", "Cat");
        myDict.Add("D", "Dog");
  
        // Getting an ICollection containing
        // the keys in OrderedDictionary
        ICollection keyCollection = myDict.Keys;
  
        // Creating a String array
        String[] myKeys = new String[myDict.Count];
  
        // Copying the OrderedDictionary elements to
        // a one-dimensional Array object at the
        // specified index.
        keyCollection.CopyTo(myKeys, 0);
  
        for (int i = 0; i < myDict.Count; i++) {
            Console.WriteLine(myKeys[i]);
        }
    }
}

输出：

A
B
C
D

参考：

• https://docs.microsoft.com/zh-cn/dotnet/api/system.collections.specialized.ordereddictionary.keys?view=netframework-4.7.2