目录
[2.使用List.Add(T) 方法](#2.使用List.Add(T) 方法)
[1.示例1：List.Add(T) 方法](#1.示例1：List.Add(T) 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
cs
// 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 index
for (int i = 0; i < indexToInsert; i++)
{
dynamicArray.Add(originalArray[i]);
}
// Insert the element at the specified index
dynamicArray.Add(elementToInsert);
// Copy remaining elements from original array to dynamic array
for (int i = indexToInsert; i < originalArray.Length; i++)
{
dynamicArray.Add(originalArray[i]);
}
// Convert dynamic array to a new array and return
return [.. dynamicArray];
}
}
}
//运行结果：
/*
1, 2, 10, 3, 4, 5
*/2.示例：自定义插入方法
cs
//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 + 1)) //判断遍历到的索引是否小于添加索引加1
TemArray[i] = ArrayBorn[i];
else if (i == (Index + 1))//判断遍历到的索引是否等于添加索引加1
TemArray[i] = Value;
else
TemArray[i] = ArrayBorn[i - 1];
}
else
{
if (i == 0)//数组首位置
TemArray[i] = Value;
else
TemArray[i] = ArrayBorn[i - 1];
}
}
return TemArray;
}
}
}
