C＃| SortedDictionary.Keys属性

此属性用于获取包含SortedDictionary中的键的集合。

句法：

public System.Collections.Generic.SortedDictionary.KeyCollection Keys { get; }

返回值：它返回一个包含SortedDictionary中的键的集合。

下面是说明上述属性的用法的程序：

范例1：

// C# code to get the keys
// in the SortedDictionary
using System;
using System.Collections.Generic;
  
class GFG {
  
    // Driver code
    public static void Main()
    {
  
        // Create a new SortedDictionary
        // of strings, with string keys.
        SortedDictionary myDict = 
          new SortedDictionary();
  
        // Adding key/value pairs in myDict
        myDict.Add("Australia", "Canberra");
        myDict.Add("Belgium", "Brussels");
        myDict.Add("Netherlands", "Amsterdam");
        myDict.Add("China", "Beijing");
        myDict.Add("Russia", "Moscow");
        myDict.Add("India", "New Delhi");
  
        // To get count of key/value pairs in myDict
        Console.WriteLine("Total key/value pairs"
            + " in myDict are : " + myDict.Count);
  
        // To get the keys alone,
        // use the Keys property.
        SortedDictionary.KeyCollection keyColl = 
                                                    myDict.Keys;
  
        // The elements of the KeyCollection
        // are strongly typed with the type
        // that was specified for dictionary
        // keys
        foreach(string s in keyColl)
        {
            Console.WriteLine("Key = {0}", s);
        }
    }
}

输出：

Total key/value pairs in myDict are : 6
Key = Australia
Key = Belgium
Key = China
Key = India
Key = Netherlands
Key = Russia

范例2：

// C# code to get the keys
// in the SortedDictionary
using System;
using System.Collections.Generic;
  
class GFG {
  
    // Driver code
    public static void Main()
    {
  
        // Create a new SortedDictionary
        // of ints, with int keys.
        SortedDictionary myDict = 
          new SortedDictionary();
  
        // Adding key/value pairs in myDict
        myDict.Add(9, 8);
        myDict.Add(3, 4);
        myDict.Add(4, 7);
        myDict.Add(1, 7);
  
        // To get count of key/value pairs in myDict
        Console.WriteLine("Total key/value pairs"
            + " in myDict are : " + myDict.Count);
  
        // To get the keys alone,
        // use the Keys property.
        SortedDictionary.KeyCollection keyColl = 
                                              myDict.Keys;
  
        // The elements of the KeyCollection
        // are strongly typed with the type
        // that was specified for dictionary
        // keys
        foreach(int s in keyColl)
        {
            Console.WriteLine("Key = {0}", s);
        }
    }
}

输出：

Total key/value pairs in myDict are : 4
Key = 1
Key = 3
Key = 4
Key = 9

参考：

• https://docs.microsoft.com/zh-cn/dotnet/api/system.collections.generic.sorteddictionary-2.keys?view=netframework-4.7.2