C#中检查ListDictionary是否包含特定的键

要检查ListDictionary是否包含特定键，代码如下-

示例

using System; using System.Collections; using System.Collections.Specialized; public class Demo { public static void Main() { ListDictionary dict1 = new ListDictionary(); dict1.Add("A", "Books"); dict1.Add("B", "Electronics"); dict1.Add("C", "Smart Wearables"); dict1.Add("D", "Pet Supplies"); dict1.Add("E", "Clothing"); dict1.Add("F", "Footwear"); Console.WriteLine("ListDictionary1 elements..."); foreach(DictionaryEntry d in dict1) { Console.WriteLine(d.Key + " " + d.Value); } ListDictionary dict2 = new ListDictionary(); 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("\nListDictionary2 key-value pairs..."); IDictionaryEnumerator demoEnum = dict2.GetEnumerator(); while (demoEnum.MoveNext()) Console.WriteLine("Key = " + demoEnum.Key + ", Value = "+ demoEnum.Value); Console.WriteLine("Is the ListDictionary having fixed size? = "+dict2.IsFixedSize); Console.WriteLine("If ListDictionary read-only? = "+dict2.IsReadOnly); Console.WriteLine("Is ListDictionary synchronized = "+dict2.IsSynchronized); Console.WriteLine("The ListDictionary has the key 5? = "+dict2.Contains("5")); } }

输出结果

这将产生以下输出-

ListDictionary1 elements... A Books B Electronics C Smart Wearables D Pet Supplies E Clothing F Footwear ListDictionary2 key-value pairs... Key = 1, Value = One Key = 2, Value = Two Key = 3, Value = Three Key = 4, Value = Four Key = 5, Value = Five Key = 6, Value = Six Is the ListDictionary having fixed size? = False If ListDictionary read-only? = False Is ListDictionary synchronized = False The ListDictionary has the key 5? = True

示例

让我们看另一个例子-

using System; using System.Collections; using System.Collections.Specialized; public class Demo { public static void Main() { ListDictionary dict = new ListDictionary(); dict.Add("1", "SUV"); dict.Add("2", "Sedan"); dict.Add("3", "Utility Vehicle"); dict.Add("4", "Compact Car"); dict.Add("5", "SUV"); dict.Add("6", "Sedan"); dict.Add("7", "Utility Vehicle"); dict.Add("8", "Compact Car"); dict.Add("9", "Crossover"); dict.Add("10", "Electric Car"); Console.WriteLine("ListDictionary elements..."); foreach(DictionaryEntry d in dict) { Console.WriteLine(d.Key + " " + d.Value); } Console.WriteLine("\nIs the ListDictionary having fixed size? = "+dict.IsFixedSize); Console.WriteLine("If ListDictionary read-only? = "+dict.IsReadOnly); Console.WriteLine("Is ListDictionary synchronized = "+dict.IsSynchronized); Console.WriteLine("The ListDictionary has the key M? = "+dict.Contains("M")); } }

输出结果

这将产生以下输出-

ListDictionary elements... 1 SUV 2 Sedan 3 Utility Vehicle 4 Compact Car 5 SUV 6 Sedan 7 Utility Vehicle 8 Compact Car 9 Crossover 10 Electric Car Is the ListDictionary having fixed size? = False If ListDictionary read-only? = False Is ListDictionary synchronized = False The ListDictionary has the key M? = False