=====Trouver la bonne déclaration pour appeler les DLL Windows=====
Télécharger la source du .NET depuis [[https://referencesource.microsoft.com/download.html|ReferenceSource]] et rechercher dans tous les fichiers ''UnsafeNativeMethods.cs'' ou dans le fichier ''win32native.cs''. Il y a presque tous les API Windows.

====Mauvaises pratiques====
===IntPtr===
Ne pas utiliser ''IntPtr'' mais ''HandleRef'' pour les paramètres de type ''HWND'' selon la ''MSDN''.
<code csharp>
IntPtr iptr = ...;
HandleRef href = new HandleRef(null, iptr);
</code>

[[https://stackoverflow.com/questions/526661/intptr-safehandle-and-handleref-explained|IntPtr, SafeHandle and HandleRef - Explained]] {{ :lang:csharp:windows:net_-_intptr_safehandle_and_handleref_-_explained_-_stack_overflow_2020-04-28_8_23_31_am_.html |Archive du 08/02/2009 le 28/04/2020}}

[[https://stackoverflow.com/questions/27348119/safehandle-and-handleref|SafeHandle and HandleRef]] {{ :lang:csharp:windows:c_-_safehandle_and_handleref_-_stack_overflow_2020-04-28_8_23_48_am_.html |Archive du 07/12/2014 le 28/04/2020}}

===LPCSTR et LPCWSTR===
Utiliser ''string'' à la place en spécifiant le ''Marshal'' pour chaque paramètre.

<code chsarp>
public static extern IntPtr FindWindowA([MarshalAs(UnmanagedType.LPStr)] string className, [MarshalAs(UnmanagedType.LPStr)] string windowName);
</code>

Il est aussi possible de mettre directement ''DllImport(CharSet = CharSet.Ansi)'' ou ''CharSet.Unicode'' mais l'analyseur statique de Visual Studio préfère l'utilisation de ''MarshalAs''.

Si ''CharSet.Ansi'' est utilisé, il est préférable de rajouter ''DllImport(BestFitMapping = false, ThrowOnUnmappableChar = true)''.

=====Récupérer le nom d'un disque dur qui est affiché depuis l'explorateur Windows et qui est différent de celui du label du disque dur=====
Ne marche qu'à partir de Windows Vista.

[[https://stackoverflow.com/questions/2843935/get-drive-label-in-c-sharp|Get drive label in C#]] {{ :lang:csharp:windows:get_drive_label_in_c_-_stack_overflow_2020-04-28_8_24_02_am_.html |Archive du 16/05/2010 le 28/04/2020}}

<code csharp>
    public const string SHELL = "shell32.dll";

    [DllImport(SHELL, CharSet = CharSet.Unicode)]
    public static extern uint SHParseDisplayName(string pszName, IntPtr zero, [Out] out IntPtr ppidl, uint sfgaoIn, [Out] out uint psfgaoOut);

    [DllImport(SHELL, CharSet = CharSet.Unicode)]
    public static extern uint SHGetNameFromIDList(IntPtr pidl, SIGDN sigdnName, [Out] out String ppszName);

    public enum SIGDN : uint
    {
        NORMALDISPLAY = 0x00000000,
        PARENTRELATIVEPARSING = 0x80018001,
        DESKTOPABSOLUTEPARSING = 0x80028000,
        PARENTRELATIVEEDITING = 0x80031001,
        DESKTOPABSOLUTEEDITING = 0x8004c000,
        FILESYSPATH = 0x80058000,
        URL = 0x80068000,
        PARENTRELATIVEFORADDRESSBAR = 0x8007c001,
        PARENTRELATIVE = 0x80080001
    }

    //var x = GetDriveLabel(@"C:\")
    public string GetDriveLabel(string driveNameAsLetterColonBackslash)
    {
        IntPtr pidl;
        uint dummy;
        string name;
        if (SHParseDisplayName(driveNameAsLetterColonBackslash, IntPtr.Zero, out pidl, 0, out dummy) == 0
            && SHGetNameFromIDList(pidl, SIGDN.PARENTRELATIVEEDITING, out name) == 0
            && name != null)
        {
            return name;
        }
        return null;
    }
</code>

=====Version de Windows=====
<code csharp>
OperatingSystem osVersionObj = Environment.OSVersion; 
 
OSVersionInfo osVersionInfo = new OSVersionInfo() 
{ 
    Name = GetOSName(osVersionObj), 
    Major = osVersionObj.Version.Major, 
    Minor = osVersionObj.Version.Minor, 
    Build = osVersionObj.Version.Build 
}; 
</code>

Correspondance :

[[https://docs.microsoft.com/en-us/windows/win32/sysinfo/operating-system-version|Operating System Version]] {{ :lang:csharp:windows:operating_system_version_-_win32_apps_microsoft_docs_2020-04-28_8_24_00_am_.html |Archive du 31/05/2018 le 28/04/2020}}

^Operating system^Version number^
|Windows 10|10.0*|
|Windows Server 2016|10.0*|
|Windows 8.1|6.3*|
|Windows Server 2012 R2|6.3*|
|Windows 8|6.2|
|Windows Server 2012|6.2|
|Windows 7|6.1|
|Windows Server 2008 R2|6.1|
|Windows Server 2008|6.0|
|Windows Vista|6.0|
|Windows Server 2003 R2|5.2|
|Windows Server 2003|5.2|
|Windows XP 64-Bit Edition|5.2|
|Windows XP|5.1|
|Windows 2000|5.0|

=====Accès bas niveau d'un disque dur=====
<del>[[https://code.msdn.microsoft.com/windowsapps/CCS-LABS-C-Low-Level-Disk-91676ca9|CCS LABS C#: Low Level Disk Access]]</del> {{ :lang:csharp:windows:ccs_labs_c_23_low_level_disk_access.zip |Archive}}

=====Ne lancer une application qu'une seule fois=====
[[https://www.codeproject.com/Articles/3014/Single-Process-Instance-Object|Single Process Instance Object]] {{ :lang:csharp:windows:single_process_instance_object_-_codeproject_2020-04-28_8_24_00_am_.html |Archive du 09/10/2002 le 28/04/2020}}
Dans ''Program.cs'' :
<code csharp>
[DllImport("user32.dll")]
private static extern bool SetForegroundWindow(IntPtr hWnd);
[DllImport("user32.dll")]
private static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")]
private static extern bool IsIconic(IntPtr hWnd);

private const int SW_RESTORE = 9;

public static void RaiseOtherProcess()
{
  Process proc = Process.GetCurrentProcess();
  // Using Process.ProcessName does not function properly when
  // the actual name exceeds 15 characters. Using the assembly 
  // name takes care of this quirk and is more accruate than 
  // other work arounds.
  string assemblyName = Assembly.GetExecutingAssembly().GetName().Name;
  foreach (Process otherProc in Process.GetProcessesByName(assemblyName))
  {
    //ignore "this" process
    if (proc.Id != otherProc.Id)
    {
      // Found a "same named process".
      // Assume it is the one we want brought to the foreground.
      // Use the Win32 API to bring it to the foreground.
      IntPtr hWnd = otherProc.MainWindowHandle;
      if (IsIconic(hWnd))
      {
        ShowWindowAsync(hWnd, SW_RESTORE);
      }
      SetForegroundWindow(hWnd);
      break;
    }
  }
}

static void Main()
{
  bool _owned;
  Mutex _processSync = new Mutex(true, Assembly.GetExecutingAssembly().GetName().Name + "RDVision", out _owned);

  if (!_owned)
  {
    RaiseOtherProcess();
    return;
  }

  // La suite.
</code>