Wried problem

[leiz]

Hi,

I am using COM to automate Word. In the main thread of my program, I
store all the Document objects from Application.Doc uments. In one event
handler (the event generated by Word), if i get all the current
documents using Application.Doc uments, the objects I got are not same
ones stored previously. The event handler is called by some threads
generated by C#. But, if I get all the current documents using my own
threads, the ones returned are the same ones previously stored.

I did synchronize and all threads are MTA.

Can anyone please tell me why this is?

Thanks a lot

[Willy Denoyette [MVP]]

"leiz" <le********@gma il.comwrote in message
news:11******** *************@i 42g2000cwa.goog legroups.com...
| Hi,
|
| I am using COM to automate Word. In the main thread of my program, I
| store all the Document objects from Application.Doc uments. In one event
| handler (the event generated by Word), if i get all the current
| documents using Application.Doc uments, the objects I got are not same
| ones stored previously. The event handler is called by some threads
| generated by C#. But, if I get all the current documents using my own
| threads, the ones returned are the same ones previously stored.
|
| I did synchronize and all threads are MTA.
|
| Can anyone please tell me why this is?
|
| Thanks a lot
|

This is not the first time you ask this, please post a complete sample that
illustrates the issue, it's really hard to help you without seeing any code.

Note that you might get better answers if you post to the
microsoft.publi c.dotnet.framew ork.interop NG.

Willy.

[leiz]

Here goes the simplified code:

using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;
using System.Runtime. InteropServices ;
using System.Threadin g;
using Word = Microsoft.Offic e.Interop.Word;

namespace btest
{
public partial class Form1 : Form
{
private Word.Applicatio n m_WordApp;

public Form1()
{
InitializeCompo nent();
m_WordApp =
(Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
m_WordApp.Windo wActivate += new
Microsoft.Offic e.Interop.Word. ApplicationEven ts4_WindowActiv ateEventHandler (Word_WindowAct ivate);

Thread t = new Thread(new ThreadStart(thr ead));
t.SetApartmentS tate(ApartmentS tate.MTA);
t.Start();
}

private void Word_WindowActi vate(Word.Docum ent doc, Word.Window
win)
{
Word.Applicatio n app =
(Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
MessageBox.Show ("In event handler " + (app == m_WordApp));
}

private void thread()
{
Word.Applicatio n app =
(Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
MessageBox.Show ("In our thread " + (app == m_WordApp));
}
}
}

=============== =============== ===============
the problem was -- in our thread the result is true, in the event
handler the result is false.

The main thread is MTA as well.

Willy Denoyette [MVP] wrote:

"leiz" <le********@gma il.comwrote in message
news:11******** *************@i 42g2000cwa.goog legroups.com...
| Hi,
|
| I am using COM to automate Word. In the main thread of my program, I
| store all the Document objects from Application.Doc uments. In one event
| handler (the event generated by Word), if i get all the current
| documents using Application.Doc uments, the objects I got are not same
| ones stored previously. The event handler is called by some threads
| generated by C#. But, if I get all the current documents using my own
| threads, the ones returned are the same ones previously stored.
|
| I did synchronize and all threads are MTA.
|
| Can anyone please tell me why this is?
|
| Thanks a lot
|

This is not the first time you ask this, please post a complete sample that
illustrates the issue, it's really hard to help you without seeing any code.

Note that you might get better answers if you post to the
microsoft.publi c.dotnet.framew ork.interop NG.

Willy.

[Willy Denoyette [MVP]]

app == m_WordApp can never be the same, both are different object
references, more they point to different RCW's instance, so even using
Object.Referenc eEquals won't help either.
Guess you want to make sure both refer to the same instance of word, well,
the only option you have is check whether there is only one single Word
instance running using the Diagnostics.Pro cess class. If there is more than
one instance, calling GetActiveObject will connect to the first instance in
the ROT, but this is not an hard guarantee.

Willy.

"leiz" <le********@gma il.comwrote in message
news:11******** *************@e 3g2000cwe.googl egroups.com...
| Here goes the simplified code:
|
| using System;
| using System.Collecti ons.Generic;
| using System.Componen tModel;
| using System.Data;
| using System.Drawing;
| using System.Text;
| using System.Windows. Forms;
| using System.Runtime. InteropServices ;
| using System.Threadin g;
| using Word = Microsoft.Offic e.Interop.Word;
|
| namespace btest
| {
| public partial class Form1 : Form
| {
| private Word.Applicatio n m_WordApp;
|
| public Form1()
| {
| InitializeCompo nent();
|
|
| m_WordApp =
| (Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
| m_WordApp.Windo wActivate += new
|
Microsoft.Offic e.Interop.Word. ApplicationEven ts4_WindowActiv ateEventHandler (Word_WindowAct ivate);
|
| Thread t = new Thread(new ThreadStart(thr ead));
| t.SetApartmentS tate(ApartmentS tate.MTA);
| t.Start();
| }
|
| private void Word_WindowActi vate(Word.Docum ent doc, Word.Window
| win)
| {
| Word.Applicatio n app =
| (Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
| MessageBox.Show ("In event handler " + (app == m_WordApp));
| }
|
| private void thread()
| {
| Word.Applicatio n app =
| (Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
| MessageBox.Show ("In our thread " + (app == m_WordApp));
| }
| }
| }
|
| =============== =============== ===============
| the problem was -- in our thread the result is true, in the event
| handler the result is false.
|
| The main thread is MTA as well.
|
| Willy Denoyette [MVP] wrote:
| "leiz" <le********@gma il.comwrote in message
| news:11******** *************@i 42g2000cwa.goog legroups.com...
| | Hi,
| |
| | I am using COM to automate Word. In the main thread of my program, I
| | store all the Document objects from Application.Doc uments. In one
event
| | handler (the event generated by Word), if i get all the current
| | documents using Application.Doc uments, the objects I got are not same
| | ones stored previously. The event handler is called by some threads
| | generated by C#. But, if I get all the current documents using my own
| | threads, the ones returned are the same ones previously stored.
| |
| | I did synchronize and all threads are MTA.
| |
| | Can anyone please tell me why this is?
| |
| | Thanks a lot
| |
| >
| This is not the first time you ask this, please post a complete sample
that
| illustrates the issue, it's really hard to help you without seeing any
code.
| >
| Note that you might get better answers if you post to the
| microsoft.publi c.dotnet.framew ork.interop NG.
| >
| Willy.
|

[leiz]

In the thread() method, the result is true and I believe that the
problem is C# thread apartment problem. Because if i used STA in main
thread, the result in thread() method is false as well.

By the way, I make sure that there is only one copy of word is running.
So, the Application object should point to the same one.
Willy Denoyette [MVP] wrote:

app == m_WordApp can never be the same, both are different object

references, more they point to different RCW's instance, so even using
Object.Referenc eEquals won't help either.
Guess you want to make sure both refer to the same instance of word, well,
the only option you have is check whether there is only one single Word
instance running using the Diagnostics.Pro cess class. If there is more than
one instance, calling GetActiveObject will connect to the first instance in
the ROT, but this is not an hard guarantee.

Willy.

"leiz" <le********@gma il.comwrote in message
news:11******** *************@e 3g2000cwe.googl egroups.com...
| Here goes the simplified code:
|
| using System;
| using System.Collecti ons.Generic;
| using System.Componen tModel;
| using System.Data;
| using System.Drawing;
| using System.Text;
| using System.Windows. Forms;
| using System.Runtime. InteropServices ;
| using System.Threadin g;
| using Word = Microsoft.Offic e.Interop.Word;
|
| namespace btest
| {
| public partial class Form1 : Form
| {
| private Word.Applicatio n m_WordApp;
|
| public Form1()
| {
| InitializeCompo nent();
|
|
| m_WordApp =
| (Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
| m_WordApp.Windo wActivate += new
|
Microsoft.Offic e.Interop.Word. ApplicationEven ts4_WindowActiv ateEventHandler (Word_WindowAct ivate);
|
| Thread t = new Thread(new ThreadStart(thr ead));
| t.SetApartmentS tate(ApartmentS tate.MTA);
| t.Start();
| }
|
| private void Word_WindowActi vate(Word.Docum ent doc, Word.Window
| win)
| {
| Word.Applicatio n app =
| (Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
| MessageBox.Show ("In event handler " + (app == m_WordApp));
| }
|
| private void thread()
| {
| Word.Applicatio n app =
| (Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
| MessageBox.Show ("In our thread " + (app == m_WordApp));
| }
| }
| }
|
| =============== =============== ===============
| the problem was -- in our thread the result is true, in the event
| handler the result is false.
|
| The main thread is MTA as well.
|
| Willy Denoyette [MVP] wrote:
| "leiz" <le********@gma il.comwrote in message
| news:11******** *************@i 42g2000cwa.goog legroups.com...
| | Hi,
| |
| | I am using COM to automate Word. In the main thread of my program, I
| | store all the Document objects from Application.Doc uments. In one
event
| | handler (the event generated by Word), if i get all the current
| | documents using Application.Doc uments, the objects I got are not same
| | ones stored previously. The event handler is called by some threads
| | generated by C#. But, if I get all the current documents using my own
| | threads, the ones returned are the same ones previously stored.
| |
| | I did synchronize and all threads are MTA.
| |
| | Can anyone please tell me why this is?
| |
| | Thanks a lot
| |
| >
| This is not the first time you ask this, please post a complete sample
that
| illustrates the issue, it's really hard to help you without seeing any
code.
| >
| Note that you might get better answers if you post to the
| microsoft.publi c.dotnet.framew ork.interop NG.
| >
| Willy.
|

[Willy Denoyette [MVP]]

"leiz" <le********@gma il.comwrote in message
news:11******** **************@ e3g2000cwe.goog legroups.com...
| In the thread() method, the result is true and I believe that the
| problem is C# thread apartment problem. Because if i used STA in main
| thread, the result in thread() method is false as well.
|
| By the way, I make sure that there is only one copy of word is running.
| So, the Application object should point to the same one.
|

Sorry I missed the point that your Main thread was MTA, well, the Main
thread MUST be STA in a Windows Forms application. Second even if you set
both to STA the result will be false, because both objects live in a
different apartment. When both are MTA they live in the same apartment and
the reference is the same, but as I said this is not a valid option.

Willy.

[leiz]

If I understand you correctly, as along as I dont use Form and set the
main thread to MTA, the result would be true, right?

I think that the problem is that the event handler is called by some
threads created by c# are in different apartment. However, when I print
out the ApartmentState in the event handler, it is a MTA, so they
should be in same apartment. Therefore, the objects should be same.

Below is the testing code. Before you run it, open a word document.
When running, swap word document and other windows. You will see that
the comparsion is true in our thread, but it is different in the event
hanlder thread.

using System;
using System.Collecti ons.Generic;
using System.Text;
using System.Threadin g;
using System.Runtime. InteropServices ;

using Word = Microsoft.Offic e.Interop.Word;

namespace btest
{
class Program
{

[MTAThread]
static void Main(string[] args)
{
new Program();
Thread.Sleep(20 000);
}

private Word.Applicatio n m_WordApp;
public Program()
{
m_WordApp =
(Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
m_WordApp.Windo wActivate += new
Microsoft.Offic e.Interop.Word. ApplicationEven ts4_WindowActiv ateEventHandler (Word_WindowAct ivate);

Thread t = new Thread(new ThreadStart(thr ead));
t.SetApartmentS tate(ApartmentS tate.MTA);
t.Start();
}

private void Word_WindowActi vate(Word.Docum ent doc, Word.Window
win)
{
Word.Applicatio n app =
(Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );

Console.WriteLi ne(Thread.Curre ntThread.GetApa rtmentState().T oString());
Console.WriteLi ne("In event handler " + (app ==
m_WordApp));
}

private void thread()
{
Word.Applicatio n app =
(Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
Console.WriteLi ne("In our thread " + (app == m_WordApp));
Thread.Sleep(20 00);
app =
(Word.Applicati on)Marshal.GetA ctiveObject("Wo rd.Application" );
Console.WriteLi ne("In our thread " + (app == m_WordApp));

}

}
}

Willy Denoyette [MVP] wrote:

"leiz" <le********@gma il.comwrote in message
news:11******** **************@ e3g2000cwe.goog legroups.com...
| In the thread() method, the result is true and I believe that the
| problem is C# thread apartment problem. Because if i used STA in main
| thread, the result in thread() method is false as well.
|
| By the way, I make sure that there is only one copy of word is running.
| So, the Application object should point to the same one.
|

Sorry I missed the point that your Main thread was MTA, well, the Main
thread MUST be STA in a Windows Forms application. Second even if you set
both to STA the result will be false, because both objects live in a
different apartment. When both are MTA they live in the same apartment and
the reference is the same, but as I said this is not a valid option.

Willy.

[Willy Denoyette [MVP]]

"leiz" <le********@gma il.comwrote in message
news:11******** **************@ b28g2000cwb.goo glegroups.com.. .
| If I understand you correctly, as along as I dont use Form and set the
| main thread to MTA, the result would be true, right?
|

Right.

| I think that the problem is that the event handler is called by some
| threads created by c# are in different apartment. However, when I print
| out the ApartmentState in the event handler, it is a MTA, so they
| should be in same apartment. Therefore, the objects should be same.
|

No they don't. The callback (the Sink interface) is running on a ThreadPool
thread which is created by the COM interop layer (through a CCW). The CCW
aggregates the free threaded marshaler and initializes the thread as NTA
(Neutral Threaded Apartment) which is always the case when you expose .NET
classes to COM clients.
That means that the callback can run on any thread, it has no apartment
requirements at all. The GetApartmentSta te returns MTA because it treats
both as compatible, but I would prefer the more correct NTA instead of MTA.
Anyway the context differs from the MTA context.
But, I guess you have a wrong idea about the references you are comparing
and what they point at.
app and m_WordApp are references to an object of type Word.Applicatio n,
however, this is not a reference to a COM object. It's a reference to a
context object (one per apartment type in the process) that holds a
hashtable holding RCW's which represents the real IUnknow/IDispatch COM
object interface.
So, when you compare app with m_WordApp, you compare whether they use the
same context, however, when they are equal, that doesn't mean that the COM
interfaces (the RCW) are the same, they are NOT. And because the RCW's
aren't the same doesn't mean that the object they refer to are different,
you see?
Honestly, I don't see what you are after by comparing these reference
really.
Willy.

[Willy Denoyette [MVP]]

"Willy Denoyette [MVP]" <wi************ *@telenet.bewro te in message
news:%2******** ********@TK2MSF TNGP04.phx.gbl. ..
|
| "leiz" <le********@gma il.comwrote in message
| news:11******** **************@ b28g2000cwb.goo glegroups.com.. .
|| If I understand you correctly, as along as I dont use Form and set the
|| main thread to MTA, the result would be true, right?
||
|
| Right.
|
|| I think that the problem is that the event handler is called by some
|| threads created by c# are in different apartment. However, when I print
|| out the ApartmentState in the event handler, it is a MTA, so they
|| should be in same apartment. Therefore, the objects should be same.
||
|
| No they don't. The callback (the Sink interface) is running on a
ThreadPool
| thread which is created by the COM interop layer (through a CCW). The CCW
| aggregates the free threaded marshaler and initializes the thread as NTA
| (Neutral Threaded Apartment) which is always the case when you expose .NET
| classes to COM clients.
| That means that the callback can run on any thread, it has no apartment
| requirements at all. The GetApartmentSta te returns MTA because it treats
| both as compatible, but I would prefer the more correct NTA instead of
MTA.
| Anyway the context differs from the MTA context.
| But, I guess you have a wrong idea about the references you are comparing
| and what they point at.
| app and m_WordApp are references to an object of type Word.Applicatio n,
| however, this is not a reference to a COM object. It's a reference to a
| context object (one per apartment type in the process) that holds a
| hashtable holding RCW's which represents the real IUnknow/IDispatch COM
| object interface.
| So, when you compare app with m_WordApp, you compare whether they use the
| same context, however, when they are equal, that doesn't mean that the COM
| interfaces (the RCW) are the same, they are NOT. And because the RCW's
| aren't the same doesn't mean that the object they refer to are different,
| you see?
| Honestly, I don't see what you are after by comparing these reference
| really.
|
|
| Willy.
Correction, after re-reading I noticed following error in above.
The callback (the Sink interface) is running on a ThreadPool
thread which is created by the COM interop layer (through a CCW).
This should read...

The callback (the Sink interface) is running on a native
thread which is created by the COM interop layer (through a CCW).

Willy.

[leiz]

Thank you very much. Now I understand what is going on there. I thought
NTA was windows2k only because of the statement in the dialog when you
create ATL objects. :p

I am kinda new to C#. Are there any methods to comparing two objects
across apartments.

Willy Denoyette [MVP] wrote:

"Willy Denoyette [MVP]" <wi************ *@telenet.bewro te in message
news:%2******** ********@TK2MSF TNGP04.phx.gbl. ..
|
| "leiz" <le********@gma il.comwrote in message
| news:11******** **************@ b28g2000cwb.goo glegroups.com.. .
|| If I understand you correctly, as along as I dont use Form and set the
|| main thread to MTA, the result would be true, right?
||
|
| Right.
|
|| I think that the problem is that the event handler is called by some
|| threads created by c# are in different apartment. However, when I print
|| out the ApartmentState in the event handler, it is a MTA, so they
|| should be in same apartment. Therefore, the objects should be same.
||
|
| No they don't. The callback (the Sink interface) is running on a
ThreadPool
| thread which is created by the COM interop layer (through a CCW). The CCW
| aggregates the free threaded marshaler and initializes the thread as NTA
| (Neutral Threaded Apartment) which is always the case when you expose .NET
| classes to COM clients.
| That means that the callback can run on any thread, it has no apartment
| requirements at all. The GetApartmentSta te returns MTA because it treats
| both as compatible, but I would prefer the more correct NTA instead of
MTA.
| Anyway the context differs from the MTA context.
| But, I guess you have a wrong idea about the references you are comparing
| and what they point at.
| app and m_WordApp are references to an object of type Word.Applicatio n,
| however, this is not a reference to a COM object. It's a reference to a
| context object (one per apartment type in the process) that holds a
| hashtable holding RCW's which represents the real IUnknow/IDispatch COM
| object interface.
| So, when you compare app with m_WordApp, you compare whether they use the
| same context, however, when they are equal, that doesn't mean that the COM
| interfaces (the RCW) are the same, they are NOT. And because the RCW's
| aren't the same doesn't mean that the object they refer to are different,
| you see?
| Honestly, I don't see what you are after by comparing these reference
| really.
|
|
| Willy.
Correction, after re-reading I noticed following error in above.
The callback (the Sink interface) is running on a ThreadPool
thread which is created by the COM interop layer (through a CCW).
This should read...

The callback (the Sink interface) is running on a native
thread which is created by the COM interop layer (through a CCW).

Willy.