Changer le papier peint du bureau à l'aide de code .NET

Question

Comment puis-je changer le papier peint de bureau à l'aide de Code C#?

Answer 1

Ici, une classe a tiré à partir d'une application, j'ai écrit un ou deux ans:

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);
    }
}

Je n'ai pas testé beaucoup, donc à utiliser à vos propres risques.

Answer 2

Peaufinage Neal N réponse pour Gifs:

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 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>
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 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>
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 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="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="transparencyReplace">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, 0 if we're already too slow 
            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();
}

Notez également que vous devez utiliser:

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;

Enfin, un clic droit sur votre Projet, Ajouter une Référence, et (dans les Assemblées et Cadre) ajouter Présentation de Base, Système.Xaml, et WindowsBase.

Puis cliquez droit sur votre Projet et aller dans les Propriétés, et assurez-vous que la Cible est le Cadre .Net Framework 4.5. Si vous changez ce que vous pouvez avoir besoin de redémarrer Visual Studio.