windows系统桌面壁纸切换的三种csharp办法，兼容win10及旧版，还有一个现成桌面小程序

我自己用这些代码做的小app如下：

最新版本已经改成了服务的方式，也可以选择性添加系统的右键菜单，并且我自己使用的源码库已经开源到了nuget，大家可以直接拿来做二次开发，

新版的下载地址为：https://www.zhaimaojun.cn/P/桌面壁纸管理器/

开源库为（可以直接在vs的nuget包管理中搜索到）：https://www.nuget.org/packages/WindowsAPI/

第一种，user32.dll

/// <summary>
        /// 调用外部切换壁纸的方法
        /// </summary>
        /// <param name="uAction"></param>
        /// <param name="uParam"></param>
        /// <param name="lpvParam"></param>
        /// <param name="fuWinIni"></param>
        /// <returns></returns>
        [DllImport("user32.dll", EntryPoint = "SystemParametersInfo")]
        public static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);

就是一种很常用，好像兼容性最好的办法吧，但是，使用的局限性很大，多显示器情况下会导致所有显示器使用相同的壁纸！而且无法区分多个显示器

第二种，IActiveDesktop

public class ActiveDesktopCom
    {
        /// <summary>
        /// 壁纸的显示方式
        /// </summary>
        public enum WPSTYLE
        {
            /// <summary>
            /// 居中
            /// </summary>
            CENTER = 0,
            /// <summary>
            /// 平铺
            /// </summary>
            TILE = 1,
            /// <summary>
            /// 拉伸
            /// </summary>
            STRETCH = 2,
            /// <summary>
            /// 适应
            /// </summary>
            adapt = 3,
            /// <summary>
            /// 填充
            /// </summary>
            FILL = 4,
            /// <summary>
            /// 跨区
            /// </summary>
            Transregional = 5,
        }

        struct WALLPAPEROPT
        {
            public int dwSize;
            public WPSTYLE dwStyle;
        }

        struct COMPONENTSOPT
        {
            public int dwSize;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fEnableComponents;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fActiveDesktop;
        }

        struct COMPPOS
        {
            public const int COMPONENT_TOP = 0x3FFFFFFF;
            public const int COMPONENT_DEFAULT_LEFT = 0xFFFF;
            public const int COMPONENT_DEFAULT_TOP = 0xFFFF;

            public int dwSize;
            public int iLeft;
            public int iTop;
            public int dwWidth;
            public int dwHeight;
            public int izIndex;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fCanResize;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fCanResizeX;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fCanResizeY;
            public int iPreferredLeftPercent;
            public int iPreferredTopPercent;
        }

        [Flags]
        enum ITEMSTATE
        {
            NORMAL = 0x00000001,
            FULLSCREEN = 00000002,
            SPLIT = 0x00000004,
            VALIDSIZESTATEBITS = NORMAL | SPLIT | FULLSCREEN,
            VALIDSTATEBITS = NORMAL | SPLIT | FULLSCREEN | unchecked((int)0x80000000) | 0x40000000
        }

        struct COMPSTATEINFO
        {
            public int dwSize;
            public int iLeft;
            public int iTop;
            public int dwWidth;
            public int dwHeight;
            public int dwItemState;
        }

        enum COMP_TYPE
        {
            HTMLDOC = 0,
            PICTURE = 1,
            WEBSITE = 2,
            CONTROL = 3,
            CFHTML = 4,
            MAX = 4
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        struct COMPONENT
        {
            private const int INTERNET_MAX_URL_LENGTH = 2084;   //   =
                                                                // INTERNET_MAX_SCHEME_LENGTH   (32)   +   "://\0".Length   +
                                                                // INTERNET_MAX_PATH_LENGTH   (2048)  

            public int dwSize;
            public int dwID;
            public COMP_TYPE iComponentType;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fChecked;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fDirty;
            [MarshalAs(UnmanagedType.Bool)]
            public bool fNoScroll;
            public COMPPOS cpPos;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
            public string wszFriendlyName;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = INTERNET_MAX_URL_LENGTH)]
            public string wszSource;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = INTERNET_MAX_URL_LENGTH)]
            public string wszSubscribedURL;

#if AD_IE5
    public   int   dwCurItemState;
    public   COMPSTATEINFO   csiOriginal;
    public   COMPSTATEINFO   csiRestored;
#endif
        }

        enum DTI_ADTIWUI
        {
            DTI_ADDUI_DEFAULT = 0x00000000,
            DTI_ADDUI_DISPSUBWIZARD = 0x00000001,
            DTI_ADDUI_POSITIONITEM = 0x00000002,
        }

        [Flags]
        enum AD_APPLY
        {
            SAVE = 0x00000001,
            HTMLGEN = 0x00000002,
            REFRESH = 0x00000004,
            ALL = SAVE | HTMLGEN | REFRESH,
            FORCE = 0x00000008,
            BUFFERED_REFRESH = 0x00000010,
            DYNAMICREFRESH = 0x00000020
        }

        [Flags]
        enum COMP_ELEM
        {
            TYPE = 0x00000001,
            CHECKED = 0x00000002,
            DIRTY = 0x00000004,
            NOSCROLL = 0x00000008,
            POS_LEFT = 0x00000010,
            POS_TOP = 0x00000020,
            SIZE_WIDTH = 0x00000040,
            SIZE_HEIGHT = 0x00000080,
            POS_ZINDEX = 0x00000100,
            SOURCE = 0x00000200,
            FRIENDLYNAME = 0x00000400,
            SUBSCRIBEDURL = 0x00000800,
            ORIGINAL_CSI = 0x00001000,
            RESTORED_CSI = 0x00002000,
            CURITEMSTATE = 0x00004000,
            ALL = TYPE | CHECKED | DIRTY | NOSCROLL | POS_LEFT | SIZE_WIDTH |
                SIZE_HEIGHT | POS_ZINDEX | SOURCE |
                FRIENDLYNAME | POS_TOP | SUBSCRIBEDURL | ORIGINAL_CSI |
                RESTORED_CSI | CURITEMSTATE
        }

        [Flags]
        enum ADDURL
        {
            SILENT = 0x0001
        }

        [
            ComImport(),
            Guid("F490EB00-1240-11D1-9888-006097DEACF9"),
            InterfaceType(ComInterfaceType.InterfaceIsIUnknown)
        ]
        interface IActiveDesktop
        {
            void ApplyChanges(AD_APPLY dwFlags);
            void GetWallpaper([MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder pwszWallpaper, int cchWallpaper, int dwReserved);
            void SetWallpaper([MarshalAs(UnmanagedType.LPWStr)] string pwszWallpaper, int dwReserved);
            void GetWallpaperOptions(ref WALLPAPEROPT pwpo, int dwReserved);
            void SetWallpaperOptions([In] ref WALLPAPEROPT pwpo, int dwReserved);
            void GetPattern([MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder pwszPattern, int cchPattern, int dwReserved);
            void SetPattern([MarshalAs(UnmanagedType.LPWStr)] string pwszPattern, int dwReserved);
            void GetDesktopItemOptions(ref COMPONENTSOPT pco, int dwReserved);
            void SetDesktopItemOptions([In] ref COMPONENTSOPT pco, int dwReserved);
            void AddDesktopItem([In] ref COMPONENT pcomp, int dwReserved);
            void AddDesktopItemWithUI(IntPtr hwnd, [In] ref COMPONENT pcomp, DTI_ADTIWUI dwFlags);
            void ModifyDesktopItem([In] ref COMPONENT pcomp, COMP_ELEM dwFlags);
            void RemoveDesktopItem([In] ref COMPONENT pcomp, int dwReserved);
            void GetDesktopItemCount(out int lpiCount, int dwReserved);
            void GetDesktopItem(int nComponent, ref COMPONENT pcomp, int dwReserved);
            void GetDesktopItemByID(IntPtr dwID, ref COMPONENT pcomp, int dwReserved);
            void GenerateDesktopItemHtml([MarshalAs(UnmanagedType.LPWStr)] string pwszFileName, [In] ref COMPONENT pcomp, int dwReserved);
            void AddUrl(IntPtr hwnd, [MarshalAs(UnmanagedType.LPWStr)] string pszSource, [In] ref COMPONENT pcomp, ADDURL dwFlags);
            void GetDesktopItemBySource([MarshalAs(UnmanagedType.LPWStr)] string pwszSource, ref COMPONENT pcomp, int dwReserved);
        }

        [
            ComImport(),
            Guid("75048700-EF1F-11D0-9888-006097DEACF9")
        ]
        class ActiveDesktop   /*   :   IActiveDesktop   */   { }
        public class OLE32DLL
        {
            [DllImport("ole32.dll", SetLastError = true)]
            public static extern int CoUninitialize();

            [DllImport("ole32.dll", SetLastError = true)]
            public static extern int CoInitialize(int pvReserved);

            [DllImport("ole32.dll", CharSet = CharSet.Unicode)]
            public static extern int CLSIDFromString(string lpsz, out Guid pclsid);

            [DllImport("ole32.dll", ExactSpelling = true, PreserveSig = false)]
            [return: MarshalAs(UnmanagedType.Interface)]
            public static extern object CoCreateInstance(
                [In, MarshalAs(UnmanagedType.LPStruct)] Guid rclsid,
                int pUnkOuter,
                int dwClsContext,
                [In, MarshalAs(UnmanagedType.LPStruct)] Guid riid
            );
        }
        /// <summary>
        /// 兼容win7版本以前版本系统的修改壁纸
        /// </summary>
        /// <param name="filename"></param>
        /// <returns></returns>
        public static bool SetActiveDesktop(string filename, WPSTYLE dwstyle = WPSTYLE.FILL)
        {
            try
            {
                const int NULL = 0;
                const int S_OK = 0;
                const int CLSCTX_ALL = 23;

                Guid IID_IActiveDesktop = new Guid("F490EB00-1240-11D1-9888-006097DEACF9");
                Guid CLSID_ActiveDesktop = new Guid("75048700-EF1F-11D0-9888-006097DEACF9");

                if (System.Threading.Thread.CurrentThread.GetApartmentState() != System.Threading.ApartmentState.STA && OLE32DLL.CoInitialize(NULL) < S_OK)
                    throw new Exception("Failed to initialize COM library.");
                //object ppvObject = CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_ALL, IID_IActiveDesktop);
                //ActiveDesktop ad = new ActiveDesktop();
                object ad = OLE32DLL.CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_ALL, IID_IActiveDesktop);
                IActiveDesktop iad = (IActiveDesktop)ad;
                if (iad != null)
                {
                    //WPSTYLE_CENTER 居中 0
                    //WPSTYLE_TILE 平铺 1
                    //WPSTYLE_STRETCH 拉伸 2
                    //WPSTYLE dwstyle = WPSTYLE.FILL;//这里调整显示背景图片样式
                    WALLPAPEROPT wp = new WALLPAPEROPT();
                    wp.dwSize = System.Runtime.InteropServices.Marshal.SizeOf(wp);
                    wp.dwStyle = dwstyle;
                    iad.SetWallpaperOptions(ref wp, 0);
                    iad.SetWallpaper(filename, 0);
                    iad.ApplyChanges(AD_APPLY.ALL);//AD_APPLY.ALL);
                    //System.Runtime.InteropServices.Marshal.ReleaseComObject(ad);
                    //ad = null;
                }
                OLE32DLL.CoUninitialize();
                return true;
            }
            catch
            {
                return false;
            }
        }
    }

以上代码也是我从网上流传的代码中复制到的，但是网上流传的代码中其中有一部分代码是有问题的：

ActiveDesktop ad = new ActiveDesktop();

就是这里，这个代码不可运行，因为这种接口中IActiveDesktop对象不能通过类型强转得到，因为ActiveDesktop实例本身就不是通过new方式得到的，而我的代码中已经将这个错误进行了修改，并且win10系统中已经确认运行无误。

第三种，IDesktopWallpaper也是一种Com接口(只支持win8以上系统，且支持多显示器独立设置壁纸)

/// <summary>
    /// 使用IDesktopWallpaper方式切换壁纸的方法
    /// </summary>
    public class DesktopWallpaperCom
    {
        [ComImport]
        [Guid("B92B56A9-8B55-4E14-9A89-0199BBB6F93B")]
        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        public interface IDesktopWallpaper
        {
            void SetWallpaper([MarshalAs(UnmanagedType.LPWStr)] string monitorID, [MarshalAs(UnmanagedType.LPWStr)] string wallpaper);

            [return: MarshalAs(UnmanagedType.LPWStr)]
            string GetWallpaper([MarshalAs(UnmanagedType.LPWStr)] string monitorID);

            [return: MarshalAs(UnmanagedType.LPWStr)]
            string GetMonitorDevicePathAt(uint monitorIndex);

            [return: MarshalAs(UnmanagedType.U4)]
            uint GetMonitorDevicePathCount();

            [return: MarshalAs(UnmanagedType.Struct)]
            Rect GetMonitorRECT([MarshalAs(UnmanagedType.LPWStr)] string monitorID);

            void SetBackgroundColor([MarshalAs(UnmanagedType.U4)] uint color);

            [return: MarshalAs(UnmanagedType.U4)]
            uint GetBackgroundColor();

            void SetPosition([MarshalAs(UnmanagedType.I4)] DesktopWallpaperPosition position);

            [return: MarshalAs(UnmanagedType.I4)]
            DesktopWallpaperPosition GetPosition();

            void SetSlideshow(IntPtr items);

            IntPtr GetSlideshow();

            void SetSlideshowOptions(DesktopSlideshowDirection options, uint slideshowTick);

            void GetSlideshowOptions(out DesktopSlideshowDirection options, out uint slideshowTick);

            void AdvanceSlideshow([MarshalAs(UnmanagedType.LPWStr)] string monitorID, [MarshalAs(UnmanagedType.I4)] DesktopSlideshowDirection direction);

            DesktopSlideshowDirection GetStatus();

            bool Enable();
        }

        [ComImport]
        [Guid("C2CF3110-460E-4fc1-B9D0-8A1C0C9CC4BD")]
        public class DesktopWallpaper
        {
        }

        [Flags]
        public enum DesktopSlideshowOptions
        {
            None = 0,
            ShuffleImages = 0x01
        }

        [Flags]
        public enum DesktopSlideshowState
        {
            None = 0,
            Enabled = 0x01,
            Slideshow = 0x02,
            DisabledByRemoteSession = 0x04
        }

        public enum DesktopSlideshowDirection
        {
            Forward = 0,
            Backward = 1
        }

        public enum DesktopWallpaperPosition
        {
            Center = 0,
            Tile = 1,
            Stretch = 2,
            Fit = 3,
            Fill = 4,
            Span = 5,
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct Rect
        {
            public int Left;
            public int Top;
            public int Right;
            public int Bottom;
        }
        /// <summary>
        /// 获取所有的显示器的ID，用于在设置壁纸中用到的显示器的id
        /// </summary>
        /// <returns></returns>
        public static string[] GetDeskMonitorIds()
        {
            try
            {
                DesktopWallpaper ad = new DesktopWallpaper();
                IDesktopWallpaper iad = (IDesktopWallpaper)ad;
                List<string> mids = new List<string>();
                if (iad != null)
                {
                    for (uint i = 0; i < iad.GetMonitorDevicePathCount(); i++)
                    {
                        mids.Add(iad.GetMonitorDevicePathAt(i));
                    }
                }
                System.Runtime.InteropServices.Marshal.ReleaseComObject(ad);
                ad = null;
                return mids.ToArray();
            }
            catch
            {
                return null;
            }
        }
        /// <summary>
        /// 新版的win8以上版本调用修改桌面的方法
        /// </summary>
        /// <param name="filename"></param>
        /// <returns></returns>
        public static bool SetDesktopWallpaper(string filename, string mid = null)
        {
            try
            {
                DesktopWallpaper ad = new DesktopWallpaper();
                IDesktopWallpaper iad = (IDesktopWallpaper)ad;
                if (iad != null)
                {
                    iad.SetWallpaper(mid ?? string.Empty, filename);
                }
                System.Runtime.InteropServices.Marshal.ReleaseComObject(ad);
                ad = null;
                return true;
            }
            catch
            {
                return false;
            }
        }
    }

这是win8系统以上才支持的一种桌面壁纸切换方法，可以支持多显示器独立进行壁纸的设置

最后放上我自己做的壁纸切换工具，可以自适应切换壁纸的方式，且支持多显示器壁纸切换管理和收藏，还有可以添加自动切换壁纸的系统任务，其中的有个vbs脚本是用于壁纸切换的，杀软一般都会报毒，但是要是文件没了就无法切换壁纸了。

下载地址是：https://www.zhaimaojun.cn/P/%e6%a1%8c%e9%9d%a2%e5%a3%81%e7%ba%b8%e7%ae%a1%e7%90%86%e5%99%a8/

以上。