Re: can not return com from c# - C# Discussion Boards

3-Sep-04 2:11

OPC defines two main components(COM) registered in opcserver category : OpcServer & OpcGroup. I have written two coresponing classes as follows that implement the required Interfaces as defined by OPC.
[Guid( "926EFA52-C020-4259-B879-203512901EAF" )]
[ProgId("FAHM OPC Server 1")]
[ComVisible( true )]
public class OpcServer: IOPCServer, IOPCCommon, IOPCItemProperties, IOPCBrowseServerAddressSpace
{}
[Guid( "075A7104-076F-481f-8CCF-11BA9AE375EB" )]
[ProgId("FAHM OPC Group 1")]
[ClassInterface(ClassInterfaceType.None)]
public class OpcGroup: IOPCItemMgt, IOPCAsyncIO2, IOPCSyncIO, IOPCGroupStateMgt
{}

I can in a not managed programming language such as delphi or c++ create an instance of them and call all methods of both of them and QueryInterface them to all implemented Interfaces and see they are working by showing just a messagebox for test.
The problem is that the IOPCServer Interface defines a method AddGroup as follows that returns an instance of OPCGroup and has following signature in c++ and c#:
c++:
virtual HRESULT STDMETHODCALLTYPE AddGroup(
/* [string][in] */ LPCWSTR szName,
/* [in] */ BOOL bActive,
/* [in] */ DWORD dwRequestedUpdateRate,
/* [in] */ OPCHANDLE hClientGroup,
/* [in][unique] */ LONG __RPC_FAR *pTimeBias,
/* [in][unique] */ FLOAT __RPC_FAR *pPercentDeadband,
/* [in] */ DWORD dwLCID,
/* [out] */ OPCHANDLE __RPC_FAR *phServerGroup,
/* [out] */ DWORD __RPC_FAR *pRevisedUpdateRate,
/* [in] */ REFIID riid,
/* [iid_is][out] */ LPUNKNOWN __RPC_FAR *ppUnk) = 0;
c# :
void AddGroup(
[In, MarshalAs(UnmanagedType.LPWStr)] string szName,
[In, MarshalAs(UnmanagedType.Bool)] bool bActive,
[In] int dwRequestedUpdateRate,
[In] int hClientGroup,
[In] ref int pTimeBias,
[In] ref float pPercentDeadband,
[In] int dwLCID,
[Out] out int phServerGroup,
[Out] out int pRevisedUpdateRate,
[In] ref Guid riid,
[Out, MarshalAs(UnmanagedType.IUnknown)] out object ppUnk);
When in the unmanged code call this method of IOPCServer, it seems to be ok, but the returned object in ppUnk that supposed to be a IOPCItemMgt fails to execute any of its methods and raises an memory exception. I tried following implementation for OPCSerevr.AddGroup but all of them have the same wrong result:
impl. 1:
Type typeofGroup = Type.GetTypeFromProgID( "FAHM OPC Group 1" );
if( typeofGroup == null )
throw new Exception("OPC Server Not Found");
object grp = Activator.CreateInstance( typeofGroup );
IntPtr pRes = IntPtr.Zero;
IntPtr pUnk = Marshal.GetIUnknownForObject(obj);
Marshal.QueryInterface(pUnk, ref riid, out pRes);
Marshal.Release(pUnk);
Marshal.Release(pUnk);
if (!pRes.Equals(IntPtr.Zero))
ppUnk = pRes;
else
Marshal.ThrowExceptionForHR(HResult.E_NOINTERFACE);
impl. 2:
object grp = new OpcGroup();
ppUnk = IntPtr.Zero;
ppUnk = Marshal.GetComInterfaceForObject(grp, typeof(IOPCItemMgt));
impl. 3:
object grp = new OpcGroup();
ppUnk = grp;
impl. 4:
object grp = new OpcGroup();
ppUnk = (IOPCItemMgt)grp;
And for each of mentioned lines in above implementaions I surrounded it with a try-catch block and showed messageboxes after each successfull or failed block, and it seems that none of them fails, but I don't know why the returned IOPCItemMgt is incorrect. Can anyone help me?
Special Regards
Umed Kurdistan

Heath Stewart3-Sep-04 7:14

Heath Stewart

3-Sep-04 7:14

A few things: first, please learn to format your code for use on CodeProject. You can use <pre></pre> tags for blocks of code, and <code></code> for inline code. This also helps separate your code from your paragraphs making it much easier to read.

Also, why two calls to Marshal.Release? Marshal.GetIUnknownForObject increments the ref count only once and I see no other code that AddRef's pUnk. This might be causing your COM server to unload if the ref count is zero and no more objects are running.

Also, I'm not sure I understand your code correctly (i.e., what you're trying to do; not COM interop which I understand very well) but you need to use Activator.CreatecomInstanceFrom if the group is actually a COM object that you've created an RCW (runtime callable wrapper) for. Just creating the Type for an RCW won't work; it needs to instantiate the COM object through its class factory.

Finally, PROGIDs should be in the forum of Library.Object.Version. It's not a hard and fast rule, but is consistent with just about every object COM object. If you want friendly names, you declare these in your IDL for native COM servers, or use the ComRegisterFunctionAttribute and ComUnregisterFunctionAttribute to additionally (class registration you still get for free from regasm.exe) register the title of the COM object using the Registry and RegistryKey classes in the Microsoft.Win32 namespace.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles]

umedkurd3-Sep-04 7:51

3-Sep-04 7:51

Thanks for your reply.

Both OPCServer & OPCGroups are defined in c# but they are regitered as COM because the OPC protocol defines so and others can be able to create instances of them.

I removed one/both Marshal.Release but it doesn't solve the problem. The problem in readable & formatted style is:

OPC (OLE for Process Control) is a protocol as an interface between
applications and industry hardware drivers. It defines two main components (COM)
registered in opcserver category : OpcServer & OpcGroup.

I have written two corresponding classes as follows that implement the required
Interfaces as defined by OPC.

-----------------------

[Guid( "926EFA52-C020-4259-B879-203512901EAF" )]

[ProgId("FAHM OPC Server 1")]

[ComVisible( true )]

public class OpcServer: IOPCServer, IOPCCommon, IOPCItemProperties,
IOPCBrowseServerAddressSpace

{

//Implementd inteface methods

}

[Guid( "075A7104-076F-481f-8CCF-11BA9AE375EB" )]

[ProgId("FAHM OPC Group 1")]

[ClassInterface(ClassInterfaceType.None)]

public class OpcGroup: IOPCItemMgt, IOPCAsyncIO2, IOPCSyncIO, IOPCGroupStateMgt

{

//Implementd inteface methods

}

I can in a not managed programming language such as delphi or c++ create an
instance of them and call all methods of both of them and QueryInterface them to
all implemented Interfaces and see they are working by showing just a messagebox
for test.

The problem is that the IOPCServer Interface defines a method AddGroup as
follows that returns an instance of OPCGroup and has following signature in c++
and c#:

c++:

virtual HRESULT STDMETHODCALLTYPE AddGroup(

        /* [string][in] */ LPCWSTR szName,

        /* [in] */ BOOL bActive,

        /* [in] */ DWORD
dwRequestedUpdateRate,

        /* [in] */ OPCHANDLE hClientGroup,

        /* [in][unique] */ LONG __RPC_FAR *pTimeBias,

        /* [in][unique] */ FLOAT __RPC_FAR *pPercentDeadband,

        /* [in] */ DWORD dwLCID,

        /* [out] */ OPCHANDLE __RPC_FAR *phServerGroup,

        /* [out] */ DWORD __RPC_FAR *pRevisedUpdateRate,

        /* [in] */ REFIID riid,

        /* [iid_is][out] */ LPUNKNOWN __RPC_FAR
*ppUnk) = 0;

c# :

void AddGroup(

        [In, MarshalAs(UnmanagedType.LPWStr)]
string szName,

        [In, MarshalAs(UnmanagedType.Bool)]
bool bActive,

        [In] int dwRequestedUpdateRate,

        [In] int hClientGroup,

        [In] ref int pTimeBias,

        [In] ref float pPercentDeadband,

        [In] int dwLCID,

        [Out] out int phServerGroup,

        [Out] out int pRevisedUpdateRate,

        [In] ref Guid riid,

        [Out,
MarshalAs(UnmanagedType.IUnknown)] out object ppUnk);

When in the unmanged code call this method of IOPCServer, it seems to be ok, but
the returned object in ppUnk that supposed to be a IOPCItemMgt fails to execute
any of its methods and raises an memory exception.

I tried following implementation for OPCSerevr.AddGroup but all of them have the
same wrong result:

------------------------------------------

impl. 1:

    Type typeofGroup = Type.GetTypeFromProgID( "FAHM OPC Group 1"
);

    if( typeofGroup == null )

    throw new Exception("OPC Server Not Found");

    object grp = Activator.CreateInstance( typeofGroup );

    IntPtr pRes = IntPtr.Zero;

    IntPtr pUnk = Marshal.GetIUnknownForObject(obj);

    Marshal.QueryInterface(pUnk, ref riid, out pRes);

    Marshal.Release(pUnk);

    if (!pRes.Equals(IntPtr.Zero))

        ppUnk = pRes;

    else


Marshal.ThrowExceptionForHR(HResult.E_NOINTERFACE);

------------------------------------------

impl. 2:

    object grp = new OpcGroup();

    ppUnk = IntPtr.Zero;

    ppUnk = Marshal.GetComInterfaceForObject(grp,
typeof(IOPCItemMgt));

------------------------------------------

impl. 3:

    object grp = new OpcGroup();

    ppUnk = grp;

------------------------------------------

impl. 4:

object grp = new OpcGroup();

ppUnk = (IOPCItemMgt)grp;

And for each of mentioned lines in above implementaions I surrounded it with a
try-catch block and showed messageboxes after each successfull or failed block,
and it seems that none of them fails, but I don't know why the returned
IOPCItemMgt is incorrect.

Can anyone help me?

Special Regards

Umed Kurdistan

Heath Stewart3-Sep-04 8:15

Heath Stewart

3-Sep-04 8:15

That's not really any better (I said use the <pre></pre> tags for fixed-width, block-level code), but wasn't necessary, either. I did manage to read your first post after scanning it several times.

Most of my remarks were about problems I found elsewhere in your code (like bad PROGIDs). In order to help you, I need more information.

I know that you're defining COM objects in C# (known as CCWs), but not being familiar with OPC I need to know if the groups you're trying to call are native COM components. If you're trying to activate a CCW, then you need to use Activator.CreateComInstanceFrom so that the class factory is used. Just instantiating the CCW itself isn't enough. There's a lot that goes on in the CLR.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles]

umedkurd3-Sep-04 18:34

3-Sep-04 18:34

No, the groups aren't native COM components, they are COM compenents defined and implemented in c# and then regitered as COM.
The Problem:

unmanaged code :
   1- Create an instance from OPCSerevr --> Is OK & can call all methods when
       casted to any interface
   2- Create an instance from OPCGroup --> Is OK & can call all methods when
       casted to any interface
   3- Call AddGroup method of OPCServer casted to IOPCServer that returns an
       OPCGroup and casting it to any interface is OK, but when i call the
       methods raises a memory error.

Thanks

Umed Ebdullahi

Heath Stewart6-Sep-04 9:10

Heath Stewart

6-Sep-04 9:10

Without seeing all the source code, all I can do is make educates "stabs in the dark", but hopefully we can resolve this. Usually the questions are a little more simple. Smile | :)

Are these interfaces declared in unmanaged code (i.e., in an IDL file and registered in HKCR\Interfaces)? If so, don't forget to attribute the re-declaration in managed code with ComImport. This ensures that the CLR performs a QueryInterface for the requested interface instead of just a cast.

If these interfaces are declared in managed code, IIRC they will not be registered in HKCR\Interfaces by regasm.exe. The easiest way to find out is to run regasm.exe /regfile:temp.reg Assembly.dll (replacing "Assembly.dll" with your assembly, of course). You could also generate a typelib and use oleview.exe Assembly.tlb for an IDL-like output, if you like.

If not registered, you can add a couple static parameterless methods and attribute them with the ComRegisterFunctionAttribute and ComUnregisterFunctionAttribute. Keep in mind that these methods are called by regasm.exe in addition to registering your types normally. No need to do the same thing twice.

Also be sure that if you don't install your assembly into the GAC, you use the /codebase option with regasm.exe to register the fully-qualified path to your assembly so that mscoree.dll knows where to find it. Since you can create instances of your COM servers, this doesn't sound like a problem.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles]

umedkurd7-Sep-04 18:42

Multiple Document Intrface problem-Ineed help

7-Sep-04 18:42

Yes these interfaces are declared in unmanged code, and I used ComImport with all interfaces and have installed my assembly into GAC.
I have emailed a copy of application source to your email, and any help will be appreciated greatly.

Special Regards.

gijoebijoe3-Sep-04 2:05

gijoebijoe

3-Sep-04 2:05

Hello,
i am facing a problem,the main window of the program has picture boxes and tab control.
A certain menu item opens the main form's child form.
However picture boxes of the parent form remains on the top of the child form.I tried using for the child form the "bringtofront" method ,but still it wont work.The child form would be totally visible if it came in an area of the parent form with no controls.Otherwise part of the child form would be covered by the controls of the parent form.
I really need the help

Thanks a million

Re: Multiple Document Intrface problem-Ineed help

sreejith ss nair3-Sep-04 2:52

It allways prints to my default printer but i want to choose the printer in code?

3-Sep-04 2:52

hi,

How you want to show the second from which is choosen by the user. If you don't mind. Is it possible to explaine a little bit more and clear.

**************************
S r e e j i t h N a i r
**************************

Exocortex.DSP question

Shiro19813-Sep-04 1:56

Shiro1981

3-Sep-04 1:56

I am currently trying out some things with Ben Houston's Exocortex.DSP Fourier functions to use with sound curves and I have a question: The FFT-function asks for a length, but I don't know what I should use as the length..... I tries the length of the float-array I use, but it keeps telling me that 'Index was outside the bounds of the array'..... can someone tell me what kind of variable I should use for it? Any help will be hugely appreciated.

greetings.

robmays3-Sep-04 1:55

robmays

3-Sep-04 1:55

whare am i going wrong.

string strDefaultPrinter = @"\\hfd-sales07\zebra tlp2742";
prtSettings.PrinterName = strDefaultPrinter;
pgSettings.Landscape = true;
printDoc.DefaultPageSettings = pgSettings;
printDoc.PrinterSettings = prtSettings;

Rectangle rect = new Rectangle(0,50,165,310);
e.Graphics.DrawRectangle(pen,rect);
e.Graphics.DrawString("From:",mFont,Brushes.Black,rect); Cry | :((

Creating a XSLT File

teo_x3-Sep-04 1:53

teo_x

3-Sep-04 1:53

I want to create a XSLT file in C#.NET manually.I mean that according to the user choice ,XSLT file will be created in background.But I know that there is not any class like XmlDocument,XmlTextWriter,XmlTextTeader for XSLT Document.How can I create this document?Should I use to File I/O class and how?I am waiting for your help...Thanks a lot...

Re: Creating a XSLT File

sreejith ss nair3-Sep-04 2:55

How to invert pixel color of a bitmap ?

3-Sep-04 2:55

hi,

Check this. It may help you out
XSLT in C#

**************************
S r e e j i t h N a i r
**************************

sachinkalse3-Sep-04 0:24

sachinkalse

3-Sep-04 0:24

hello,
I am trying to change Black color in the given bitmap to White,
and vise versa, keeping rest of the colors as it is.
The idea is some what explained in the code below.
Off course the code is not correct, it just explains what i want to do.
Please guide me.

private void Form1_Load(object sender, System.EventArgs e)
{
OpenFileDialog dlg = new OpenFileDialog();
dlg.Filter="Image files (*.BMP, *.JPG, *.GIF)|*.bmp;*.jpg;*.gif";
if(dlg.ShowDialog()==DialogResult.OK)
{
Image img = Image.FromFile(dlg.FileName);
Bitmap bm = new Bitmap(img, img.Size);
for(int y=0;y

Re: How to invert pixel color of a bitmap ?

sreejith ss nair3-Sep-04 2:44

Re: How to invert pixel color of a bitmap ?

3-Sep-04 2:44

hi
I found one article which deals these all things. this may serve your purpose.

Click Me

**************************
S r e e j i t h N a i r
**************************

sachinkalse5-Sep-04 22:17

sachinkalse

5-Sep-04 22:17

Solved it !!!
pasting the same for the community
-----------------------------------------------------

Bitmap _bitmap = new Bitmap(_originalmage, _originalmage.Size);

BitmapData data = _bitmap.LockBits(
new Rectangle(0, 0, _bitmap.Width, _bitmap.Height), ImageLockMode.ReadWrite,
PixelFormat.Format24bppRgb);
if (data != null)
{
unsafe
{
//
// Refering all eliments
//
byte * p = (byte *)data.Scan0.ToPointer();

for (int y = 0; y < data.Height; y++)
{
for (int c = 0; c < data.Stride; c += 3)
{
// GET RGB
byte b = p[c];
byte g = p[c+1];
byte r = p[c+2];

// ToDo :: Reverse
if (b == 0 && g == 0 && r == 0)
{
// SetPixcel to WHITE
p[c] = 255;
p[c+1] = 255;
p[c+2] = 255;
}
else if (b == 255 && g == 255 && r == 255)
{
// SetPixcel to BLACK
p[c] = 0;
p[c+1] = 0;
p[c+2] = 0;
}
}
p += data.Stride;
}
}
}

_bitmap.UnlockBits(data);

-------------------------------------------------

regards Big Grin | :-D

Pluggin' in the Plug-In - HMOG

Sebastian Schneider3-Sep-04 0:20

Sebastian Schneider

3-Sep-04 0:20

Hello again, "ich sag einfach Hello again"...

I have some question about a problem which seems to elude me. I did some research on plug-in frameworks (still working on my service here) and it seems to be a very useful feature to have a "pluggable" service.

Since the CodeGenerator SAP calls the ".NET Connector" will generate only code which becomes invalid after a single change to the corresponding structure in SAP, we should be able to simply replace that function with the proper one (hence, plug-in).

This would also enable us to have a service which could be extended with "Function Modules" as requirements change.

Well, I wrote an interface, implemented it in my Plugin and referenced it from both "host application" and "plugin library".

Now, I have a little trouble passing information along.

I have found one article here on CodeProject, but that referred to C++. Maybe I am just too stupid.

How can I pass my important data (as an object) between host-app and plug-in ?

Cheers
Sebastian

Cant change the Expandable property from property grid

pradeep_pc3-Sep-04 0:15

pradeep_pc

3-Sep-04 0:15

Hi All,

In my C++.NET application, the 'ndStud' object is displayed in a Property Browser. 'ndStud' object has nested properties. While changing the 'StudSize' property from the property grid, the application hangs.

If i remove the NotifyParentProperty attribute from the sub properties of StudSize (Feet & Inches), the application works, but still cant modify it's values from the property grid.

What should i do in order to make it editable from the property grid (it works at run-time)?

Plz see the code bellow:

[Serializable]
TypeConverter(__typeof(System::ComponentModel::ExpandableObjectConverter))]
__gc public class ndLength
{
private:
int feet;
int inches;
public:
ndLength()
{
feet = 0;
inches = 0;
}
ndLength(int feet,int inches)
{
this->feet = feet;
this->inches = inches;
}

[NotifyParentProperty(true), RefreshProperties(RefreshProperties::Repaint)]

__property int get_Feet()
{
return feet;
}

__property void set_Feet(int value)
{
feet = value;
}

[NotifyParentProperty(true), RefreshProperties (RefreshProperties::Repaint)]
__property int get_Inches()
{
return inches;
}
__property void set_Inches(int value)
{
inches = value;
}

};
[Serializable]
[TypeConverter(__typeof(System::ComponentModel::ExpandableObjectConverter))]
__gc public class ndStud
{
:
:
:
:
:
:
:

[DesignerSerializationVisibility (DesignerSerializationVisibility::Content)]
__property ndLength* get_StudSize()
{

}

__property void set_StudSize(ndLength* value)
{

}

};

}

thanks,
Pradeep

Re: Cant change the Expandable property from property grid

sreejith ss nair3-Sep-04 2:40