LANCER LES OPTIONS D'IMPRESSION D'UNE IMPRIMANTE

private const int DM_IN_BUFFER = 8;
private const int DM_OUT_BUFFER = 2;
private const int DM_IN_PROMPT = 4;

/// <summary>
/// The DocumentProperties functions display pages for printer properties.
/// </summary>
/// <param name="hwnd">handle to parent window</param>
/// <param name="hPrinter">handle to printer object</param>
/// <param name="pDeviceName">device name</param>
/// <param name="pDevModeOutput">modified device mode</param>
/// <param name="pDevModeInput">original device mode</param>
/// <param name="fMode">mode options</param>
/// <returns></returns>
[DllImport("winspool.Drv", EntryPoint = "DocumentPropertiesW", SetLastError = true, ExactSpelling = true, CallingConvention = CallingConvention.StdCall)]
static extern int DocumentProperties(IntPtr hwnd, IntPtr hPrinter, [MarshalAs(UnmanagedType.LPWStr)] string pDeviceName, IntPtr pDevModeOutput, IntPtr pDevModeInput, int fMode);

/// <summary>
/// Locks a global memory object and returns a pointer to the first byte of the object's memory block
/// </summary>
/// <param name="hMem">A handle to the global memory object</param>
/// <returns>Value is the size of the buffer required to contain the printer driver initialization data</returns>
[DllImport("kernel32.dll")]
static extern IntPtr GlobalLock(IntPtr hMem);

/// <summary>
/// Decrements the lock count associated with a memory object
/// </summary>
/// <param name="hMem">A handle to the global memory object</param>
/// <returns></returns>
[DllImport("kernel32.dll")]
static extern bool GlobalUnlock(IntPtr hMem);

/// <summary>
/// Frees the specified global memory object and invalidates its handle
/// </summary>
/// <param name="hMem">A handle to the global memory object</param>
/// <returns></returns>
[DllImport("kernel32.dll")]
static extern IntPtr GlobalFree(IntPtr hMem);


/// <summary>
/// Open the Properties dialog of a pinter
/// </summary>
private void OpenPrinterPropertiesDialog()
{
    PrinterSettings s = new PrinterSettings(); //PrintSettings peut aussi être obtenue par la propriété du même nom de l'objet PrintDialog 
    s.PrinterName = @"\\******\****"; //Nom de l'imprimante
    OpenPrinterPropertiesDialog(s);
}

/// <summary>
/// Open the Properties dialog of the selected pinter
/// </summary>
/// <param name="printerSettings">Specifies information about how a document is printed, including the printer that prints it</param>
private void OpenPrinterPropertiesDialog(PrinterSettings printerSettings)
{
    //Creates a handle to a DEVMODE structure that corresponds to the printer settings
    IntPtr hDevMode = printerSettings.GetHdevmode(printerSettings.DefaultPageSettings);
    
    //Locks the DEVMODE Handle
    IntPtr pDevMode = GlobalLock(hDevMode);

    //Retrieve size of the buffer for the new DEVMODE
    int sizeNeeded = DocumentProperties(this.Handle, IntPtr.Zero, printerSettings.PrinterName, pDevMode, pDevMode, 0);
    IntPtr devModeData = Marshal.AllocHGlobal(sizeNeeded);
    
    //Lauching the printer property dialog
    DocumentProperties(this.Handle, IntPtr.Zero, printerSettings.PrinterName, devModeData, pDevMode, DM_IN_BUFFER | DM_IN_PROMPT | DM_OUT_BUFFER);
    
    //Unlock the DEVMODE
    GlobalUnlock(hDevMode);

    //Sets the new DEVMODE to the PrinterSettings object
    printerSettings.SetHdevmode(devModeData);
    printerSettings.DefaultPageSettings.SetHdevmode(devModeData);

    //Free the DEVMODEs
    GlobalFree(hDevMode);
    Marshal.FreeHGlobal(devModeData);
}