C# |从指定索引处开始将整个数组列表复制到一维数组中
原文:https://www . geesforgeks . org/c-sharp-将整个数组列表复制到 1-d-array-从指定索引处开始/
数组列表。CopyTo(Array，Int32)方法用于将整个数组列表复制到兼容的一维数组中，从目标数组的指定索引处开始。
语法:
public virtual void CopyTo (Array array, int arrayIndex);
参数:
数组:一维数组是从数组列表中复制的元素的目的地。数组必须具有从零开始的索引。
数组索引:是数组中开始复制的从零开始的索引。
异常:
- 参数空异常:如果数组为空。
- argumentout of range exception:如果数组索引小于零。
- ArgumentException: 如果数组是多维的 或 源数组列表中的元素数量大于目标数组可以包含的元素数量。
- InvalidCastException: 如果源数组列表的类型不能自动转换为目标数组的类型。
以下程序说明了上述方法的使用:
例 1:
// C# code to illustrate the
// ArrayList.CopyTo(Array, Int32)
// Method
using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating an ArrayList
ArrayList myList = new ArrayList();
// Adding elements to ArrayList
myList.Add("A");
myList.Add("B");
myList.Add("C");
myList.Add("D");
// Creates and initializes the
// one-dimensional target Array.
String[] arr = new String[6];
// adding elements to Array
arr[0] = "HTML";
arr[1] = "PHP";
arr[2] = "Java";
arr[3] = "Python";
arr[4] = "C#";
arr[5] = "OS";
Console.WriteLine("Before Method: ");
Console.WriteLine("\nArrayList Contains: ");
// Displaying the elements in myList
for (int i = 0; i < myList.Count; i++) {
Console.WriteLine("myList[{0}] : {1}", i, myList[i]);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
Console.WriteLine("After Method: ");
// Copying the entire source ArrayList
// to the target Array starting at
// index 2.
myList.CopyTo(arr, 2);
Console.WriteLine("\nArrayList Contains: ");
// Displaying the elements in myList
for (int i = 0; i < myList.Count; i++) {
Console.WriteLine("myList[{0}] : {1}", i, myList[i]);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
}
}
输出:
Before Method:
ArrayList Contains:
myList[0] : A
myList[1] : B
myList[2] : C
myList[3] : D
Array Contains:
arr[0] : HTML
arr[1] : PHP
arr[2] : Java
arr[3] : Python
arr[4] : C#
arr[5] : OS
After Method:
ArrayList Contains:
myList[0] : A
myList[1] : B
myList[2] : C
myList[3] : D
Array Contains:
arr[0] : HTML
arr[1] : PHP
arr[2] : A
arr[3] : B
arr[4] : C
arr[5] : D
例 2:
// C# code to illustrate the
// ArrayList.CopyTo(Array, Int32)
// Method
using System;
using System.Collections;
class GFG {
// Driver code
public static void Main()
{
// Creating an ArrayList
ArrayList myList = new ArrayList();
// Adding elements to ArrayList
myList.Add("A");
myList.Add("B");
myList.Add("C");
myList.Add("D");
// Creates and initializes the
// one-dimensional target Array.
// Here array size is only 2 i.e
// it can hold only 3 elements.
String[] arr = new String[2];
Console.WriteLine("Before Method: ");
Console.WriteLine("\nArrayList Contains: ");
// Displaying the elements in myList
for (int i = 0; i < myList.Count; i++) {
Console.WriteLine("myList[{0}] : {1}", i, myList[i]);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
Console.WriteLine("After Method: ");
// using Method but It will give
// Runtime Error as number of elements
// in the source ArrayList is greater
// than the number of elements that
// the destination array can contain
myList.CopyTo(arr, 2);
Console.WriteLine("\nArrayList Contains: ");
// Displaying the elements in myList
for (int i = 0; i < myList.Count; i++) {
Console.WriteLine("myList[{0}] : {1}", i, myList[i]);
}
Console.WriteLine("\nArray Contains: ");
// Displaying the elements in arr
for (int i = 0; i < arr.Length; i++) {
Console.WriteLine("arr[{0}] : {1}", i, arr[i]);
}
}
}
运行时错误:
未处理异常: 系统。参数异常:目标数组不够长。检查目标索引和长度，以及数组的下限 参数名称:目标数组
参考:
版权属于：月萌API www.moonapi.com，转载请注明出处
