使用.NET代码更改桌面壁纸

Question

我怎样使用C#代码更改桌面壁纸？

- Sauron

Answer 1

这是我从我一两年前写的一个应用程序中提取出来的一个类:

public sealed class Wallpaper
{
    Wallpaper() { }

    const int SPI_SETDESKWALLPAPER = 20;
    const int SPIF_UPDATEINIFILE = 0x01;
    const int SPIF_SENDWININICHANGE = 0x02;

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

    public enum Style : int
    {
        Tiled,
        Centered,
        Stretched
    }

    public static void Set(Uri uri, Style style)
    {
        System.IO.Stream s = new System.Net.WebClient().OpenRead(uri.ToString());

        System.Drawing.Image img = System.Drawing.Image.FromStream(s);
        string tempPath = Path.Combine(Path.GetTempPath(), "wallpaper.bmp");
        img.Save(tempPath, System.Drawing.Imaging.ImageFormat.Bmp);

        RegistryKey key = Registry.CurrentUser.OpenSubKey(@"Control Panel\Desktop", true);
        if (style == Style.Stretched)
        {
            key.SetValue(@"WallpaperStyle", 2.ToString());
            key.SetValue(@"TileWallpaper", 0.ToString());
        }

        if (style == Style.Centered)
        {
            key.SetValue(@"WallpaperStyle", 1.ToString());
            key.SetValue(@"TileWallpaper", 0.ToString());
        }

        if (style == Style.Tiled)
        {
            key.SetValue(@"WallpaperStyle", 1.ToString());
            key.SetValue(@"TileWallpaper", 1.ToString());
        }

        SystemParametersInfo(SPI_SETDESKWALLPAPER,
            0,
            tempPath,
            SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE);
    }
}

我没有进行过全面测试，所以使用时需要自己承担风险。

- Neil N

---

不确定Windows是否支持JPEG作为壁纸...在设置为壁纸之前，它会将其他图像转换为BMP格式（如果我错了，请纠正我）。如果是这种情况，您必须在代码中进行转换。 - Umair Ahmed

我已经很好地使用它来处理JPEG文件了。代码中称其为BMP并不限制其使用。它可能也适用于PNG和GIF等其他格式，但我还没有验证过。 - Neil N

@NeilN 这很棒，但如果想要添加一个复选框“空白壁纸”来将壁纸设置为黑色呢！ - Murhaf Sousli

FYI：这段代码无法处理PNG格式的图片。我不得不先手动转换成BMP格式。 - Program.X

哇！它完全可以工作，并且支持JPG...做得非常好。恭喜。 - Umut D.

Answer 2

根据这个有用的答案，我也制作了自己的应用程序以设置与屏幕分辨率匹配的壁纸。

但是注册表设置是错误的。以下是正确的值（在Win 7、Win 8.1、Win 10上测试）。

if (style == Style.Fill)
{
    key.SetValue(@"WallpaperStyle", 10.ToString());
    key.SetValue(@"TileWallpaper", 0.ToString());
}
if (style == Style.Fit)
{
    key.SetValue(@"WallpaperStyle", 6.ToString());
    key.SetValue(@"TileWallpaper", 0.ToString());
}
if (style == Style.Span) // Windows 8 or newer only!
{
    key.SetValue(@"WallpaperStyle", 22.ToString());
    key.SetValue(@"TileWallpaper", 0.ToString());
}
if (style == Style.Stretch)
{
    key.SetValue(@"WallpaperStyle", 2.ToString());
    key.SetValue(@"TileWallpaper", 0.ToString());
}
if (style == Style.Tile)
{
    key.SetValue(@"WallpaperStyle", 0.ToString());
    key.SetValue(@"TileWallpaper", 1.ToString());
}
if (style == Style.Center)
{
    key.SetValue(@"WallpaperStyle", 0.ToString());
    key.SetValue(@"TileWallpaper", 0.ToString());
}

- badsamaritan

---

为什么要使用(number).ToString()，而不是"(number)"？ - HighTechProgramming15

当然可以。这只是一个概念问题 - 我之所以这样写，是因为别人也这样写过。 - badsamaritan

Answer 3

如果您想临时设置桌面壁纸而不会污染 Windows 设置历史记录，那么这是我制作的一个要点。它备份了 壁纸历史记录（存储在注册表中）在设置临时壁纸之前，您可以在之后恢复它。

https://gist.github.com/Drarig29/4aa001074826f7da69b5bb73a83ccd39

- Drarig29

Answer 4

如果你正在使用C#中的UWP，这里是我找到的代码here。

using Windows.System.UserProfile; 

// Pass in a relative path to a file inside the local appdata folder 
async Task<bool> SetWallpaperAsync(string localAppDataFileName) 
{ 
   bool success = false; 
   if (UserProfilePersonalizationSettings.IsSupported())       
   {
       var uri = new Uri("ms-appx:///Local/" + localAppDataFileName);
       StorageFile file = await StorageFile.GetFileFromApplicationUriAsync(uri);
       UserProfilePersonalizationSettings profileSettings = UserProfilePersonalizationSettings.Current;
       success = await profileSettings.TrySetWallpaperImageAsync(file);
   }
}

其实我认为可以更简单一些。file.png是你的照片，它可以是.jpg或其他格式。

StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync("file.png", CreationCollisionOption.ReplaceExisting);
bool success = false;
UserProfilePersonalizationSettings profileSettings = UserProfilePersonalizationSettings.Current;
success = await profileSettings.TrySetWallpaperImageAsync(file);

- Poyi Hong

Answer 5

调整Neal N的Gifs答案：

private const int SPI_SETDESKWALLPAPER = 20;
private const int SPIF_UPDATEINIFILE = 0x01;
private const int SPIF_SENDWININICHANGE = 0x02;

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

public enum Style : int
{
    Tiled,
    Centered,
    Stretched
}

/// <summary>
/// Loops numFrames times, animating the desktop background as the given gif.
/// Remember this will sorta bog down your computer, and probably isn't best to be running 24/7.
/// If numFrames is negative this will loop forever
/// </summary>
/// <param name="gifPath">The gif to be animated</param>
/// <param name="transparencyReplace">If the gif has transparency, it will be "replaced" with this color.</param>
/// <param name="framesPerSecond">How many frames to play per second. This is a max: most likely it will be a little slower than this especially at first.</param>
/// <param name="style">Whether to tile, center, or stretch each gif frame as it's played.</param>
/// <param name="numFrames">The number of frames to play. If negative, this method will loop forever.</param>
public static void SetDesktopBackgroundAsGifAsync(string gifPath, System.Drawing.Color transparencyReplace, int framesPerSecond, Style style, int numFrames)
{
    Thread workerThread = new Thread(() => SetDesktopBackgroundAsGif(gifPath, transparencyReplace, framesPerSecond, style, numFrames));
    workerThread.Start();
}

/// <summary>
/// Loops numFrames times, animating the desktop background as the given gif.
/// Remember this will sorta bog down your computer, and probably isn't best to be running 24/7.
/// If num frames is negative this will loop forever. 
//// <summary>
/// <param name="gifPath">The gif to be animated</param>
/// <param name="backgroundImage">Image to render the gif on top of (because of transparency)</param>
/// <param name="framesPerSecond">How many frames to play per second. This is a max: most likely it will be a little slower than this.</param>
/// <param name="style">Whether to tile, center, or stretch each gif frame as it's played.</param>
/// <param name="numFrames">The number of frames to play. If negative, this method will loop forever.</param>
public static void SetDesktopBackgroundAsGifAsync(string gifPath, System.Drawing.Image backgroundImage, int framesPerSecond, Style style, int numFrames)
{
    Thread workerThread = new Thread(() => SetDesktopBackgroundAsGif(gifPath, backgroundImage, framesPerSecond, style, numFrames));
    workerThread.Start();
}

/// <summary>
/// Loops numFrames times, animating the desktop background as the given gif.
/// Remember this will sorta bog down your computer, and probably isn't best to be running 24/7. 
/// if numFrames is negative this will loop forever
/// </summary>
/// <param name="gifPath">The gif to be animated</param>
/// <param name="transparencyReplace">If the gif has transparency, it will be "replaced" with this color.</param>
/// <param name="framesPerSecond">How many frames to play per second. This is a max: most likely it will be a little slower than this.</param>
/// <param name="style">Whether to tile, center, or stretch each gif frame as it's played.</param>
/// <param name="numFrames">The number of frames to play. If negative, this method will loop forever.</param>
public static void SetDesktopBackgroundAsGif(string gifPath, System.Drawing.Color transparencyReplace, int framesPerSecond, Style style, int numFrames)
{
    if (!File.Exists(gifPath))
        throw new Exception("Given gif: '" + gifPath + "' not found");

    FileStream gifFile = new FileStream(gifPath, FileMode.Open);

    GifBitmapDecoder gifDecoder = new GifBitmapDecoder(gifFile, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);

    if (gifDecoder.Frames.Count == 0)
        throw new Exception("No frames in given gif");

    Bitmap backgroundImage = new Bitmap(gifDecoder.Frames[0].PixelWidth, gifDecoder.Frames[0].PixelHeight, System.Drawing.Imaging.PixelFormat.Format32bppArgb);

    using(Graphics g = Graphics.FromImage(backgroundImage))
    {
        g.FillRectangle(new System.Drawing.SolidBrush(transparencyReplace), 0, 0, gifDecoder.Frames[0].PixelWidth, gifDecoder.Frames[0].PixelHeight);
    }

    gifFile.Close();

    SetDesktopBackgroundAsGif(gifPath, backgroundImage, framesPerSecond, style, numFrames);
}

/// <summary>
/// Loops infinitely, animating the desktop background as the given gif.
/// Remember this will sorta bog down your computer, and probably isn't best to be running 24/7. 
/// </summary>
/// <param name="gifPath">The gif to be animated</param>
/// <param name="backgroundImage">Image to render the gif on top of (because of transparency)</param>
/// <param name="framesPerSecond">How many frames to play per second. This is a max: most likely it will be a little slower than this.</param>
/// <param name="style">Whether to tile, center, or stretch each gif frame as it's played.</param>
/// <param name="numFrames">The number of frames to play. If negative, this method will loop forever.</param>
private static void SetDesktopBackgroundAsGif(string gifPath, System.Drawing.Image backgroundImage, int framesPerSecond, Style style, int numFrames)
{
    if (!File.Exists(gifPath))
        throw new Exception("Given gif: '" + gifPath + "' not found");

    FileStream gifFile = new FileStream(gifPath, FileMode.Open);

    GifBitmapDecoder gifDecoder = new GifBitmapDecoder(gifFile, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);

    if (gifDecoder.Frames.Count == 0)
        throw new Exception("No frames in given gif");

    Console.WriteLine("Saving frames to temporary files:");

    int numFramesSoFar = 0;

    for (int i = 0; i < gifDecoder.Frames.Count; i++)
    {
        BitmapFrame gifFrame = gifDecoder.Frames[i];
        PngBitmapEncoder pngEncoder = new PngBitmapEncoder();
        pngEncoder.Frames.Add(gifFrame);
        MemoryStream pngStream = new MemoryStream();
        pngEncoder.Save(pngStream);
        Image frameImage = Image.FromStream(pngStream);
        Bitmap bmp = new Bitmap(frameImage.Width, frameImage.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
        using (Graphics g = Graphics.FromImage(bmp))
        {
            g.DrawImage(backgroundImage, 0, 0);
            g.DrawImageUnscaled(frameImage, 0, 0);
        }
        string tempPath = Path.Combine(Path.GetTempPath(), gifPath + i + ".bmp");
        bmp.Save(tempPath, System.Drawing.Imaging.ImageFormat.Bmp);

        Console.WriteLine("Saved frame " + i);

        numFramesSoFar++;

        if (numFrames >= 0 && numFramesSoFar >= numFrames) break;
    }

    Console.WriteLine("Setting frames to desktop background at about " + framesPerSecond + " FPS");

    // 1.0/... to convert to seconds per frame (instead of frames per second)
    // * 1000 to convert to milliseconds per frame
    // * 1000 to convert to microseconds per frame
    // * 10 to convert to 0.1s of microseconds per frame = 100s of nanoseconds per frame
    long ticksBetweenFrames = (long)Math.Round(1.0 / framesPerSecond) * 1000*1000*10;

    Stopwatch timer = new Stopwatch();
    timer.Start();

    numFramesSoFar = 0;

    while(numFrames < 0 || numFramesSoFar < numFrames)
    {
        for (int i = 0; i < gifDecoder.Frames.Count; i++)
        {
            // Sleep until we're at the desired frame rate, if needed.
            if(ticksBetweenFrames > timer.ElapsedTicks)
                Thread.Sleep(new TimeSpan(Math.Max(0, ticksBetweenFrames - timer.ElapsedTicks)));

            timer.Restart();

            // From https://dev59.com/zHNA5IYBdhLWcg3wL6oc#1061682

            string filePath = Path.Combine(Path.GetTempPath(), "wallpaper" + i + ".bmp");

            RegistryKey key = Registry.CurrentUser.OpenSubKey(@"Control Panel\Desktop", true);

            if (style == Style.Stretched)
            {
                key.SetValue(@"WallpaperStyle", 2.ToString());
                key.SetValue(@"TileWallpaper", 0.ToString());
            }

            if (style == Style.Centered)
            {
                key.SetValue(@"WallpaperStyle", 1.ToString());
                key.SetValue(@"TileWallpaper", 0.ToString());
            }

            if (style == Style.Tiled)
            {
                key.SetValue(@"WallpaperStyle", 1.ToString());
                key.SetValue(@"TileWallpaper", 1.ToString());
            }

            SystemParametersInfo(SPI_SETDESKWALLPAPER,
                0,
                filePath,
                SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE);

            numFramesSoFar++;

            if (numFrames >= 0 && numFramesSoFar >= numFrames) break;
        }
    }

    gifFile.Close();
}

还要注意你需要使用：

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Media;
using System.Windows.Media.Imaging;

最后，在项目上右键单击，选择“添加引用”，在“程序集和框架”中添加Presentation Core、System.Xaml和WindowsBase。

然后，在项目上右键单击并进入“属性”，确保目标框架为.Net Framework 4.5。如果更改了此设置，则可能需要重新启动Visual Studio。

- Phylliida

---

当然会使机器变慢。有一个带有随意抛入 Thread.Sleep 调用的阻塞无限循环。有更好的方法来等待时间过去。 - Cody Gray

不，我认为这更多与对SystemParametersInfo的调用有关（比如每秒钟10次）。桌面不应该像那样刷新。这可以通过运行调用此方法的程序，将“explorer”的CPU使用率从0％增加到6-12％来证明。我修改了我的答案，添加了异步方法，并使对Thread.Sleep的调用不那么频繁（仅在需要时发生）。还有其他值得关注的问题吗？ - Phylliida

我考虑过通过另一种方法来停止线程，但这似乎对于一个可能本来就不是很好的做法而言有些过度了。 - Phylliida

转念一想，我添加了一个numFrames参数，它指定在此方法停止之前要动画的帧数。如果为负数，它将永远执行下去。 - Phylliida

等待并听取什么？ - Phylliida