ActiveDir Sample
This sample demonstrates how to adjust the default apartment setting of a managed object passing data to an unmanaged method that calls the CoInitialize method. The CoInitialize method initializes a COM library in a single-threaded apartment (STA). By default, C# clients are initialized in multithreaded apartments (MTA). Visual Basic 2005 clients are initialized as STA objects and do not need to be adjusted.
The ActiveDir sample uses the following unmanaged method, shown with its original function declaration:
DsBrowseForContainer exported from Dsuiext.dll.
int DsBrowseForContainer(PDSBROWSEINFO pInfo);
In C#, the STAThreadAttribute attribute creates an STA apartment. Because STA is the default apartment setting for Visual Basic 2005 clients, no attribute is required. The Marshal.SizeOf method dynamically calculates the size of the unmanaged structure.
Declaring Prototypes
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
Public Structure DsBrowseInfo
Public Const MAX_PATH As Integer = 256
Public Size As Integer
Public OwnerHandle As IntPtr
Public Caption As String
Public Title As String
Public Root As String
Public Path As String
Public PathSize As Integer
Public Flags As Integer
Public Callback As IntPtr
Public Param As Integer
Public ReturnFormat As Integer
Public UserName As String
Public Password As String
Public ObjectClass As String
Public ObjectClassSize As Integer
End Structure
Public Class LibWrap
' Declares a managed prototype for the unmanaged function.
Declare Unicode Function DsBrowseForContainerW Lib "dsuiext.dll" ( _
ByRef info As DSBrowseInfo ) As Integer
Public Const DSBI_ENTIREDIRECTORY As Integer = &H90000
Public Const ADS_FORMAT_WINDOWS As Integer = 1
Public Enum BrowseStatus
BrowseError = -1
BrowseOk = 1
BrowseCancel = 2
End Enum
End Class
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Unicode)]
public struct DsBrowseInfo
{
public const int MAX_PATH = 256;
public int Size;
public IntPtr OwnerHandle;
public string Caption;
public string Title;
public string Root;
public string Path;
public int PathSize;
public int Flags;
public IntPtr Callback;
public int Param;
public int ReturnFormat;
public string UserName;
public string Password;
public string ObjectClass;
public int ObjectClassSize;
}
public class LibWrap
{
// Declares a managed prototype for the unmanaged function.
[DllImport("dsuiext.dll", CharSet=CharSet.Unicode)]
public static extern int DsBrowseForContainerW(ref DsBrowseInfo info);
public const int DSBI_ENTIREDIRECTORY = 0x00090000;
public const int ADS_FORMAT_WINDOWS = 1;
public enum BrowseStatus
{
BrowseError = -1,
BrowseOk = 1,
BrowseCancel = 2
}
}
[StructLayout(LayoutKind::Sequential, CharSet=CharSet::Unicode)]
public value struct DsBrowseInfo
{
public:
static int MAX_PATH = 256;
int Size;
IntPtr OwnerHandle;
String^ Caption;
String^ Title;
String^ Root;
String^ Path;
int PathSize;
int Flags;
IntPtr Callback;
int Param;
int ReturnFormat;
String^ UserName;
String^ Password;
String^ ObjectClass;
int ObjectClassSize;
};
public ref class LibWrap
{
public:
// Declares a managed prototype for the unmanaged function.
[DllImport("dsuiext.dll", CharSet=CharSet::Unicode)]
static int DsBrowseForContainerW(DsBrowseInfo^ info);
static int DSBI_ENTIREDIRECTORY = 0x00090000;
static int ADS_FORMAT_WINDOWS = 1;
enum class BrowseStatus
{
BrowseError = -1,
BrowseOk = 1,
BrowseCancel = 2
};
};
Calling Functions
Public Class App
' Must be marked as STA because the default is MTA.
' DsBrowseForContainerW calls CoInitialize, which initializes the
' COM library as STA.
<STAThread> _
Public Shared Sub Main()
Dim dsbi As New DsBrowseInfo()
dsbi.Size = Marshal.SizeOf(GetType(DsBrowseInfo))
dsbi.PathSize = DsBrowseInfo.MAX_PATH
dsbi.Caption = "Container Selection Example"
dsbi.Title = "Select a container from the list."
dsbi.ReturnFormat = LibWrap.ADS_FORMAT_WINDOWS
dsbi.Flags = LibWrap.DSBI_ENTIREDIRECTORY
dsbi.Root = "LDAP:"
dsbi.Path = New String(New Char(DsBrowseInfo.MAX_PATH){})
' Initialize remaining members...
Dim status As Integer = LibWrap.DsBrowseForContainerW(dsbi)
if CType(status, LibWrap.BrowseStatus) = LibWrap.BrowseStatus.BrowseOk Then
Console.WriteLine(dsbi.Path)
Else
Console.WriteLine("No path returned.")
End If
End Sub
End Class
class App
{
// Must be marked as STA because the default is MTA.
// DsBrowseForContainerW calls CoInitialize, which initializes the
// COM library as STA.
[STAThread]
public static void Main()
{
DsBrowseInfo dsbi = new DsBrowseInfo();
dsbi.Size = Marshal.SizeOf(typeof(DsBrowseInfo));
dsbi.PathSize = DsBrowseInfo.MAX_PATH;
dsbi.Caption = "Container Selection Example";
dsbi.Title = "Select a container from the list.";
dsbi.ReturnFormat = LibWrap.ADS_FORMAT_WINDOWS;
dsbi.Flags = LibWrap.DSBI_ENTIREDIRECTORY;
dsbi.Root = "LDAP:";
dsbi.Path = new string(new char[DsBrowseInfo.MAX_PATH]);
// Initialize remaining members...
int status = LibWrap.DsBrowseForContainerW(ref dsbi);
if ((LibWrap.BrowseStatus)status == LibWrap.BrowseStatus.BrowseOk)
{
Console.WriteLine(dsbi.Path);
}
else
{
Console.WriteLine("No path returned.");
}
}
}
public ref class App
{
public:
// Must be marked as STA because the default is MTA.
// DsBrowseForContainerW calls CoInitialize, which initializes the
// COM library as STA.
[STAThread]
static void Main()
{
DsBrowseInfo dsbi;
// Initialize the fields.
dsbi.Size = Marshal::SizeOf(DsBrowseInfo::typeid);
dsbi.PathSize = DsBrowseInfo::MAX_PATH;
dsbi.Caption = "Container Selection Example";
dsbi.Title = "Select a container from the list.";
dsbi.ReturnFormat = LibWrap::ADS_FORMAT_WINDOWS;
dsbi.Flags = LibWrap::DSBI_ENTIREDIRECTORY;
dsbi.Root = "LDAP:";
dsbi.Path = gcnew String(gcnew array<Char>(DsBrowseInfo::MAX_PATH));
// Initialize remaining members...
int status = LibWrap::DsBrowseForContainerW(dsbi);
if ((LibWrap::BrowseStatus)status == LibWrap::BrowseStatus::BrowseOk)
{
Console::WriteLine(dsbi.Path);
}
else
{
Console::WriteLine("No path returned.");
}
}
};