CoInitializeEx initializes the COM library for use by the calling thread, sets the thread's concurrency model, and creates a new apartment for the thread if one is required. Values for the dwCoInit parameter are taken from the COINIT enumeration. However, since pinvoke is a dotNET construct you should be aware that dotNET already does a COM initialization and therefore calling a CoInitializeEx function most likely will not do what you expect. This problem occurs when trying to instantiate a COM object from within dotNET where the COM objects threading model is different from dotNETs. Search on Common Language Runtime or CLR and COINIT_APARTMENTTHREADED to find posts on this issue.

C# Signature:

public enum CoInit
{
    MultiThreaded = 0x0,
    ApartmentThreaded = 0x2,
    DisableOLE1DDE = 0x4,
    SpeedOverMemory = 0x8
}

[DllImport("ole32.dll")]
public static extern int CoInitializeEx(IntPtr pvReserved, CoInit coInit);

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

// Note: PreserveSig=false allows .NET interop to handle processing the returned HRESULT and throw an exception on failure

          public enum CoInit
          {
             MultiThreaded = 0x0,
             ApartmentThreaded = 0x2,
             DisableOLE1DDE = 0x4,
             SpeedOverMemory = 0x8
          }

        [DllImport( "Ole32.dll", ExactSpelling=true, EntryPoint="CoInitializeEx", CallingConvention=CallingConvention.StdCall, SetLastError=false, PreserveSig=false ) ]
        public static extern void CoInitializeEx(IntPtr pvReserved, CoInit coInit);

Alternative Managed API:

Do you know one? Please contribute it!

Documentation

CoInitializeEx on MSDN

Please edit this page!

Do you have...

helpful tips or sample code to share for using this API in managed code?
corrections to the existing content?
variations of the signature you want to share?
additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).

Access PInvoke.net directly from VS:

Find References

Show Printable Version

Revisions

Show changes