Ändern Sie das Desktop-Hintergrundbild mithilfe von Code in .NET

Wie kann ich das Desktop-Hintergrundbild mit C # -Code ändern?

Hier ist eine Klasse, die aus einer App gezogen wurde, die ich vor ein oder zwei Jahren geschrieben habe:

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);
    }
}

Ich habe es nicht ausgiebig getestet. Verwenden Sie es daher auf eigenes Risiko.

Basierend auf dieser nützlichen Antwort habe ich auch meine eigene App erstellt , um die Bildschirmauflösung für das Hintergrundbild anzupassen.

Die Registrierungseinstellungen waren jedoch falsch. Hier sind die richtigen Werte (getestet unter Win 7, Win 8.1, Win 10).

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());
}

Wenn Sie UWP in c # verwenden, finden Sie hier den Code, den ich hier gefunden habe

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);
   }
}

Eigentlich denke ich, es kann einfacher sein file.png ist dein Foto, es kann .jpg sein oder etwas anderes

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

Wenn Sie vorübergehend ein Desktop-Hintergrundbild festlegen möchten, ohne den Windows-Einstellungsverlauf zu verschmutzen, habe ich Folgendes zusammengestellt.

Es sichert den Hintergrundbildverlauf (in der Registrierung gespeichert), bevor das temporäre Hintergrundbild festgelegt wird, und Sie können es anschließend wieder herstellen.

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

Neal Ns Antwort für Gifs optimieren:

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 http://stackoverflow.com/a/1061682/2924421

            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();
}

Beachten Sie auch, dass Sie Folgendes verwenden müssen:

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;

Klicken Sie abschließend mit der rechten Maustaste auf Ihr Projekt, fügen Sie eine Referenz hinzu und fügen Sie (in Assemblies und Framework) Presentation Core, System.Xaml und WindowsBase hinzu.

Klicken Sie dann mit der rechten Maustaste auf Ihr Projekt, gehen Sie zu Eigenschaften und stellen Sie sicher, dass Target Framework .Net Framework 4.5 ist. Wenn Sie dies ändern, müssen Sie Visual Studio möglicherweise neu starten.