C#修改电脑桌面图

public class Win32Helper
{
    [DllImport("user32.dll", EntryPoint = "SystemParametersInfoA")]
    internal static extern Int32 SystemParametersInfo(Int32 uAction, Int32 uParam, string lpvparam, Int32 fuwinIni);
}

void SetWallpaper(string imgPath)
{
    int nResult;
    nResult = Win32Helper.SystemParametersInfo(20, 1, imgPath, 0x1 | 0x2);
}