We all know that in .NET, we don't need to worry about memory leak
becaseu GC does a nice job to collect it.

The only time we need to worry about memory leak is when we use
unmanaged resources, such as COM-based objects written in C++, for an
instance. Therefore, I've created the following sample code below to
illustrate the step necessary in disposing unmanaged resources.

I believe that to dispose unmanaged resources, we'll need to call the
Destructor of the COM object. However, I don't know what's the right
syntax. I'm looking for advice and input on the piece of code below.
Thanks!

using System;
using System.Runtime.InteropServices;

namespace iopmb
{


[DllImport("user32.dll", EntryPoint="MessageBoxW",
CharSet=CharSet.Auto, ExactSpelling=true)]
public static extern bool COMDbConnection (string connectionString,
bool useTrustedConnection, string, userName, string password);

COMDbConnection myConnection = new
COMDbConnection("Provider=sqloledb;Data Source=DataWarehouse;Initial
Catalog=Pace;", true, "sa", "password") ;

try
{
// do something with myConnection
}
catch
{
finally
{
myConnection.Dispose() ;
}

}


class COMDbConnection
{
protected override void Dispose(bool disposing)
{
if (disposing)
{
// Call distructor of the COM object. I know this is not right to
clean memory this way.
// But if anyone points out the right way, I'd appreciate it!
this.~COMDbConnection();
}
// This should be skipped
//base.Dispose(disposing);
}
}

On Mar 17, 5:11*pm, Curious <fir5tsi...@yahoo.com> wrote:
> We all know that in .NET, we don't need to worry about memory leak
> becaseu GC does a nice job to collect it.
>
> The only time we need to worry about memory leak is when we use
> unmanaged resources, such as COM-based objects written in C++, for an
> instance. Therefore, I've created the following sample code below to
> illustrate the step necessary in disposing unmanaged resources.
>
> I believe that to dispose unmanaged resources, we'll need to call the
> Destructor of the COM object. However, I don't know what's the right
> syntax. I'm looking for advice and input on the piece of code below.
> Thanks!
>
> using System;
> using System.Runtime.InteropServices;
>
> * * * namespace iopmb
> * * * {
>
> * * * * * [DllImport("user32.dll", EntryPoint="MessageBoxW",
> CharSet=CharSet.Auto, ExactSpelling=true)]
> * * * * * public static extern bool COMDbConnection (string connectionString,
> bool useTrustedConnection, string, userName, string password);
>
> * * * * * COMDbConnection myConnection = new
> COMDbConnection("Provider=sqloledb;Data Source=DataWarehouse;Initial
> Catalog=Pace;", true, "sa", *"password") ;
>
> * * * * * try
> * * * * * {
> * * * * * * * * // do something with myConnection
> * * * * * }
> * * * * * catch
> * * * * * {
> * * * * * finally
> * * * * * {
> * * * * * * * * myConnection.Dispose() ;
> * * * * * }
>
> * * * }
>
> * * * class COMDbConnection
> * * * {
> * * * * protected override void Dispose(bool disposing)
> * * * * {
> * * * * * * if (disposing)
> * * * * * * {
> * * * * * * * * // Call distructor of the COM object. I know this is not right to
> clean memory this way.
> * * * * * * * * // But if anyone points out the right way,I'd appreciate it!
> * * * * * * * * this.~COMDbConnection();
> * * * * * * }
> * * * * * * // This should be skipped
> * * * * * * //base.Dispose(disposing);
> * * * * }
> * * * }

Hi,

I think you should use Marshal.ReleaseComObject method

HTH,
Sergey

Curious wrote:
> We all know that in .NET, we don't need to worry about memory leak
> becaseu GC does a nice job to collect it.
>
> The only time we need to worry about memory leak is when we use
> unmanaged resources, such as COM-based objects written in C++, for an
> instance. Therefore, I've created the following sample code below to
> illustrate the step necessary in disposing unmanaged resources.
>
> I believe that to dispose unmanaged resources, we'll need to call the
> Destructor of the COM object. However, I don't know what's the right
> syntax. I'm looking for advice and input on the piece of code below.
> Thanks!
>
> using System;
> using System.Runtime.InteropServices;
>
> namespace iopmb
> {
>
>
> [DllImport("user32.dll", EntryPoint="MessageBoxW",
> CharSet=CharSet.Auto, ExactSpelling=true)]
> public static extern bool COMDbConnection (string connectionString,
> bool useTrustedConnection, string, userName, string password);
>
> COMDbConnection myConnection = new
> COMDbConnection("Provider=sqloledb;Data Source=DataWarehouse;Initial
> Catalog=Pace;", true, "sa", "password") ;
>
> try
> {
> // do something with myConnection
> }
> catch
> {
> finally
> {
> myConnection.Dispose() ;
> }
>
> }
>
>
> class COMDbConnection
> {
> protected override void Dispose(bool disposing)
> {
> if (disposing)
> {
> // Call distructor of the COM object. I know this is not right to
> clean memory this way.
> // But if anyone points out the right way, I'd appreciate it!
> this.~COMDbConnection();
> }
> // This should be skipped
> //base.Dispose(disposing);
> }
> }
>


According to Dispose pattern, you must call overload Dispose() method in
destructor but you called destructor in Dispose() method.



--
Thanks,
Duy Lam Phuong