C#向数组指定索引位置插入新的元素值：自定义插入方法 vs List＜T＞.Add(T) 方法

目录

一、使用的方法

1.自定义插入方法 

2.使用List.Add(T) 方法

二、实例

1.示例1：List.Add(T) 方法

2.示例：自定义插入方法

---

一、使用的方法

1.自定义插入方法 

        首先需要定义一个一维数组，然后修改数组的长度(这里使用Length属性获取数组的长度，然后加1，作为新数组的长度)，从而在其中增加一个元素。只有增加了数组的长度以后才能在这个数组中增加新的元素。

2.使用List<T>.Add(T) 方法

        关于 List<T>.Add(T) 定义，详见本文作者写的其他文章，C#用Array类的FindAll方法和List＜T＞类的Add方法按关键词在数组中检索元素并输出-CSDN博客  https://wenchm.blog.csdn.net/article/details/136032895

        首先，创建一个与原始数组大小相同的动态数组（例如，List<T>）。然后，将原始数组的元素复制到动态数组中，直到到达要插入元素的索引位置。在动态数组中插入新元素。将原始数组中剩余的元素复制到动态数组中。最后，将动态数组转换回数组并返回。

二、实例

1.示例1：List<T>.Add(T) 方法

// 将一个元素插入到现有数组的指定索引位置，
// 并将原来位于该位置的元素向后移动namespace _095_1
{class Program{static void Main(string[] args){ArgumentNullException.ThrowIfNull(args);int[] originalArray = [1, 2, 3, 4, 5];int elementToInsert = 10;int indexToInsert = 2;int[] newArray = InsertElement(originalArray, elementToInsert, indexToInsert);Console.WriteLine(string.Join(", ", newArray));}static int[] InsertElement(int[] originalArray, int elementToInsert, int indexToInsert){List<int> dynamicArray = new(originalArray.Length);// Copy elements from original array to dynamic array until the insertion indexfor (int i = 0; i < indexToInsert; i++){dynamicArray.Add(originalArray[i]);}// Insert the element at the specified indexdynamicArray.Add(elementToInsert);// Copy remaining elements from original array to dynamic arrayfor (int i = indexToInsert; i < originalArray.Length; i++){dynamicArray.Add(originalArray[i]);}// Convert dynamic array to a new array and returnreturn [.. dynamicArray];}}
}
//运行结果：
/*
1, 2, 10, 3, 4, 5*/

2.示例：自定义插入方法

//在既有数组中的指定位置插入一个新的元素，
//并遍历输出新数组
namespace _095
{public partial class Form1 : Form{private Button? button1;private Button? button2;private Label? label1;private Label? label2;private TextBox? textBox1;private TextBox? textBox2;private RichTextBox? richTextBox1;private Label? label3;private TextBox? textBox3;private int[] int_array = new int[8];public Form1(){InitializeComponent();StartPosition = FormStartPosition.CenterScreen;Load += Form1_Load;}private void Form1_Load(object? sender, EventArgs e){// // button1// button1 = new Button{Location = new Point(12, 9),Name = "button1",Size = new Size(75, 23),TabIndex = 0,Text = "生成数组",UseVisualStyleBackColor = true};button1.Click += Button1_Click;// // button2// button2 = new Button{Location = new Point(224, 36),Name = "button2",Size = new Size(43, 23),TabIndex = 1,Text = "确定",UseVisualStyleBackColor = true};            button2.Click += Button2_Click;// // label1// label1 = new Label{AutoSize = true,Location = new Point(12, 42),Name = "label1",Size = new Size(56, 17),TabIndex = 2,Text = "插入索引"};// // label2// label2 = new Label{AutoSize = true,Location = new Point(12, 69),Name = "label2",Size = new Size(56, 17),TabIndex = 3,Text = "新数组："};// // textBox1// textBox1 = new TextBox{Location = new Point(93, 9),Name = "textBox1",Size = new Size(174, 23),TabIndex = 4};// // textBox2// textBox2 = new TextBox{Location = new Point(73, 36),Name = "textBox2",Size = new Size(40, 23),TabIndex = 5};          // // richTextBox1// richTextBox1 = new RichTextBox{Location = new Point(12, 90),Name = "richTextBox1",Size = new Size(254, 44),TabIndex = 6,Text = ""};// // label3// label3 = new Label{AutoSize = true,Location = new Point(118, 42),Name = "label3",Size = new Size(56, 17),TabIndex = 7,Text = "插入元素"};// // textBox3// textBox3 = new TextBox{Location = new Point(179, 36),Name = "textBox3",Size = new Size(40, 23),TabIndex = 8};// // Form1// AutoScaleDimensions = new SizeF(7F, 17F);AutoScaleMode = AutoScaleMode.Font;ClientSize = new Size(279, 146);Controls.Add(textBox3);Controls.Add(label3);Controls.Add(richTextBox1);Controls.Add(textBox2);Controls.Add(textBox1);Controls.Add(label2);Controls.Add(label1);Controls.Add(button2);Controls.Add(button1);Name = "Form1";Text = "在数组中添加一个元素";}/// <summary>/// 生成数组事件/// 遍历生成整形数组，并遍历输出/// </summary>private void Button1_Click(object? sender, EventArgs e){textBox1!.Clear();for (int i = 0; i < int_array.GetUpperBound(0) + 1; i++){int_array[i] = i;}for (int i = 0; i < int_array.GetUpperBound(0) + 1; i++){textBox1.Text += int_array[i] + " ";}}/// <summary>/// 确定插入事件/// 在生成的数组索引=4的位置插入一个元素，并遍历输出/// 这个事件不仅调用AddArray方法，更是在调用该方法之后改变了数组的大小/// </summary>private void Button2_Click(object? sender, EventArgs e){richTextBox1!.Clear();if ((textBox2!.Text != "")&& (textBox3!.Text !="")&& (textBox3!.Text.Length == 1)){int_array = AddArray(int_array, Convert.ToInt32(textBox2!.Text), Convert.ToInt32(textBox3!.Text));for (int i = 0; i < int_array.GetUpperBound(0) + 1; i++){richTextBox1.Text += int_array[i] + " ";}}else{MessageBox.Show("输入信息不能为空且元素长度恒为1", "提示");}}/// <summary>/// 向数组中插入单个元素的方法/// </summary>/// <param name="ArrayBorn">要向其中添加元素的一维数组</param>/// <param name="Index">添加索引</param>/// <param name="Value">添加值</param>/// <returns></returns>static int[] AddArray(int[] ArrayBorn, int Index, int Value){if (Index >= ArrayBorn.Length)Index = ArrayBorn.Length - 1;int[] TemArray = new int[ArrayBorn.Length + 1];//声明一个新的数组for (int i = 0; i < TemArray.Length; i++){if (Index >= 0){if (i < (Index))        //判断遍历到的索引是否小于添加索引加1TemArray[i] = ArrayBorn[i];else if (i == (Index))//判断遍历到的索引是否等于添加索引加1TemArray[i] = Value;elseTemArray[i] = ArrayBorn[i - 1];}else{if (i == 0)//数组首位置TemArray[i] = Value;elseTemArray[i] = ArrayBorn[i - 1];}}return TemArray;}}
}