在C# 中的 KeyNotFoundException
当你尝试查找的键不存在于 Dictionary 集合中时,会引发 KeyNotFoundException。
让我们看一个示例 −
示例
using System;
using System.Collections.Generic;
public class Demo {
public static void Main() {
try {
var dict = new Dictionary<string, string>() {
{"TV", "Electronics"},
{"Laptop", "Computers"},
};
Console.WriteLine(dict["Pen Drive"]);
}
catch (Exception e) {
Console.WriteLine(e);
}
}
}以下是输出。由于键不在字典中,因此可见错误 KeyNotFoundException −
输出
System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary. at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <902ab9e386384bec9c07fa19aa938869>:0
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