一个用C#开发的桌面背景切换APP

1、设计代码

        private void InitializeComponent()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1));
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.button3 = new System.Windows.Forms.Button();
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(270, 228);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 0;
            this.button1.Text = "确认";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(179, 228);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(75, 23);
            this.button2.TabIndex = 1;
            this.button2.Text = "下一张";
            this.button2.UseVisualStyleBackColor = true;
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // button3
            // 
            this.button3.Location = new System.Drawing.Point(80, 228);
            this.button3.Name = "button3";
            this.button3.Size = new System.Drawing.Size(75, 23);
            this.button3.TabIndex = 2;
            this.button3.Text = "上一张";
            this.button3.UseVisualStyleBackColor = true;
            this.button3.Click += new System.EventHandler(this.button3_Click);
            // 
            // pictureBox1
            // 
            this.pictureBox1.Location = new System.Drawing.Point(38, 12);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(393, 177);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
            this.pictureBox1.TabIndex = 3;
            this.pictureBox1.TabStop = false;
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(470, 276);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.button3);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
            this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
            this.MaximizeBox = false;
            this.Name = "Form1";
            this.Text = "壁纸切换";
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            this.ResumeLayout(false);

        }

2、事件函数

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using static System.Windows.Forms.VisualStyles.VisualStyleElement;
using Microsoft.Win32;



namespace WallpaperToggle
{
    public partial class Form1 : Form
    {

        List<string> imagePaths = GetImagePaths("C:\\Users\\Administrator\\Pictures\\Saved Pictures");
        int num = 0;

        static List<string> GetImagePaths(string folderPath)
        {
            List<string> imagePaths = new List<string>();
            string[] imageExtensions = { ".jpg", ".jpeg", ".png", ".gif", ".bmp" }; // 定义常见的图片文件扩展名
            try
            {
                foreach (string file in Directory.GetFiles(folderPath))
                {
                    string extension = Path.GetExtension(file).ToLower();
                    if (Array.IndexOf(imageExtensions, extension) >= 0)
                    {
                        imagePaths.Add(file);
                    }
                }
            }
            catch (Exception e)
            {
                Console.WriteLine($"Error occurred: {e.Message}");
            }
            return imagePaths;
        }



        public Form1()
        {
            InitializeComponent();
            pictureBox1.Image = Image.FromFile(imagePaths[num]);
        }

        [DllImport("user32.dll", EntryPoint = "SystemParametersInfo")]
        public static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);

        /// <summary>
        /// 更换壁纸
        /// </summary>
        /// <param name="fileName">壁纸文件的路径</param>
        /// <returns>操作结果：true为更换成功，false为更换失败</returns>
        public static bool ChangeWallPaper(string fileName)
        {
            if (string.IsNullOrEmpty(fileName))
            {
                return false;
            }
            if (File.Exists(fileName) == false)
            {
                return false;
            }

            fileName = Path.GetFullPath(fileName);
            var nResult = SystemParametersInfo(20, 1, fileName, 0x1 | 0x2); //更换壁纸
            if (nResult == 0)
            {
                return false;
            }
            else
            {
                RegistryKey hk = Registry.CurrentUser;
                RegistryKey run = hk.CreateSubKey(@"Control Panel\Desktop\");
                run.SetValue("Wallpaper", fileName);

                return true;
            }
        }



        private void button1_Click(object sender, EventArgs e)
        {
            ChangeWallPaper(imagePaths[num]);
        }



        private void button3_Click(object sender, EventArgs e)
        {
            if (num > 0)
            {
                num--;

            }
            else {
                num = imagePaths.Count - 1;
            }
            pictureBox1.Image = Image.FromFile(imagePaths[num]);

        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (num < imagePaths.Count - 1) {
                num++;
            }
            else
            {
                num = 0;
            }
            pictureBox1.Image = Image.FromFile(imagePaths[num]);
        }



    }
}

3、界面展示