C# |将有序字典元素复制到指定索引处的数组实例中

原文:https://www . geeksforgeeks . org/c-sharp-copy-ordereddictionary-elements-to-array-instance-at-the-specific-index/

OrderedDictionary。CopyTo(Array，Int32)方法用于将 OrderedDictionary 元素复制到指定索引处的一维 Array 对象。

语法:

public void CopyTo (Array array, int index);

参数:

数组:是一维数组，是从 OrderedDictionary 复制的 DictionaryEntry 对象的目的地。数组必须具有从零开始的索引。

索引:是数组中开始复制的从零开始的索引。

注: 序字典。CopyTo(Array，Int32)方法不提供任何保证来维护 OrderedDictionary 集合中元素的顺序。

以下程序说明了上述方法的使用:

例 1:

// C# code to copy OrderedDictionary to
// Array instance at the specified index
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver code
    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");

        DictionaryEntry[] myArr = new DictionaryEntry[myDict.Count];

        // Copying OrderedDictionary to Array
        // instance at the specified index
        myDict.CopyTo(myArr, 0);

        // Displaying elements in myArr
        for (int i = 0; i < myArr.Length; i++) {
            Console.WriteLine(myArr[i].Key + "-->" 
                                + myArr[i].Value);
        }
    }
}

输出:

key3-->value3
key4-->value4
key5-->value5
key2-->value2
key1-->value1

例 2:

// C# code to copy OrderedDictionary to
// Array instance at the specified index
// that give ArgumentOutOfRangeException
// due to the negative index
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver code
    public static void Main()
    {

        // Creating a orderedDictionary named myDict
        OrderedDictionary myDict = new OrderedDictionary();

        // Adding key and value in myDict
        myDict.Add("C", "1");
        myDict.Add("C++", "2");
        myDict.Add("Java", "3");
        myDict.Add("C#", "4");

        DictionaryEntry[] myArr = new DictionaryEntry[myDict.Count];

        // Copying OrderedDictionary to Array
        // instance at the specified index
        // This will raise "ArgumentOutOfRangeException"
        // as index is less than 0
        myDict.CopyTo(myArr, -2);

        // Displaying elements in myArr
        for (int i = 0; i < myArr.Length; i++) {
            Console.WriteLine(myArr[i].Key + "-->" 
                                + myArr[i].Value);
        }
    }
}

运行时错误:

未处理异常: 系统。ArgumentOutOfRangeException:要求非负数。 参数名称:arrayIndex

参考:

版权属于：月萌API www.moonapi.com，转载请注明出处

本文链接：https://moonapi.com/news/28004.html