Thread marshalling problem - C# Discussion Boards

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Re: Object reference not set to an instance of an object?

Member 428013630-Dec-08 2:09

Member 4280136

30-Dec-08 2:09

Also you might want to have a look at using a container rather than fixed arrays. For example a List:

http://msdn.microsoft.com/en-us/library/6sh2ey19.aspx[^]

how can i import another projects/language .exe file into my project to run in C#

D V kirankumar30-Dec-08 1:48

D V kirankumar

30-Dec-08 1:48

Hi all,
this is kiran I am new to C# development and I have a issue that
I have to import R-project into C# for statistical analysis but
I don't know how to do this if possible can any one suggest me how can I proceed farther.

Thanks & Regards;
kiran

Re: how can i import another projects/language .exe file into my project to run in C#

Christian Graus30-Dec-08 4:26

Christian Graus

30-Dec-08 4:26

What is R-project ? The answer is no. You can use Process.Start to run another exe, but your interaction with the exe will be limited.

Christian Graus

Driven to the arms of OSX by Vista.

Re: how can i import another projects/language .exe file into my project to run in C#

D V kirankumar30-Dec-08 23:00

D V kirankumar

30-Dec-08 23:00

Hi,
thanks for replay
R-Project is an statistical computing and graphing language and tool its available in .exe file if u give any some more details about this problem it will be help full to me.

Subclassing Help

JimWWhite30-Dec-08 1:22

JimWWhite

30-Dec-08 1:22

Can someone point me to a good article on how to subclass form and control objects? I want to take the base form and base form controls such as textboxes, listboxes, grids, etc. and create my own subclasses and store them in a library. Then I want to be able to easily refer to them on the toolbar instead of the base class objects when I design my applications.

Thanks!
Jim

Re: Subclassing Help

Brij30-Dec-08 2:14

Brij

30-Dec-08 2:14

Do you want some custom properties in the controls?Then you need to derived classes from textboxes, listboxes, grids, etc and add you properties and mathods.

Cheers!!
Brij

Re: Subclassing Help

JimWWhite31-Dec-08 1:24

JimWWhite

31-Dec-08 1:24

What I want to do is to first subclass the base form in .Net and add properties and methods to it that my app will use when I develop a module. Then I want to do the same thing with textboxes, comboboxes, and any other typed of control that I can place on a form. I want then to be able to (at design time) see and select my derived/subclassed objects, including the form on the toolbar and be able to select from that list.

I understand this is possible but I've not found an article on how this is done. Can someone point me to an article out there I can get to that will describe in detail how to do this?

Thanks!
Jim

Thread marshalling problem

Member 428013630-Dec-08 0:47

Member 4280136

30-Dec-08 0:47

Hi I have a problem that I cannot figure.

I have stripped the code down to a few lines that show the issue below.

Basically I have a worker thread that obtains an object and then makes a method call on that object that works fine. But when I return the object to the parent thread, from the parent thread the method call on that object fails. This is the problem. I have a guess about why it fails, but am not sure how to resolve it.

It may be that I need to do something extra to marshal the object back to the parent thread (as you can see I am not doing anything at all right now)

If the worker thread isn't marked as STAThread then the method call in the worker thread fails too, indicating that there is COM stuff going on in the background. I guess the problem is that the underlying object returned creates a COM object in the worker thread's apartment. When the object is invoked from the parent thread the method fails because the underlying COM object doesn't belong to the apartment of the parent thread. Does that sound at all correct?

Is there any way to resolve this?

class Program
{
    static AutomationElement searchResult;

        [STAThread]
        static void ThreadFunc()
        {
            searchResult = FindObject();
            searchResult.FindAllChildren(); //Method PASSES!
        }

        [STAThread]
        static void Main(string[] args)
        {
            Thread t = new Thread(new ThreadStart(ThreadFunc));
            t.SetApartmentState(ApartmentState.STA);
            t.Start();
            t.Join();
            MyObject obj = searchResult;
            obj.FindAllChildren(); //Method FAILS!
        }
    }
}

Re: Thread marshalling problem

Natza Mitzi30-Dec-08 4:33

Natza Mitzi

30-Dec-08 4:33

Please specify what is fail? An Exception ? Do you have any error messages?

Natza Mitzi

Re: Thread marshalling problem

Member 428013630-Dec-08 5:14

Member 4280136

30-Dec-08 5:14

Thanks for the reply. No exceptions occur, the fail is simply that it returns an empty array instead of an array of its children.

Since my post I have also discovered that some of the properties like Name, etc of the AutomationElement object also return empty values when called from the other thread. What appears to be happening is the AutomationElement in this case is only valid in the thread it was created in.

AutomationElement is a .Net class, I have no visibility of it's implementation, but perhaps in this case it's using COM objects internally which and these only work in the thread they were created in.

I was expecting .Net would take care of that kind of thing and marshal whatever it needs over to the other thread. Guess I am mistaken. Although really that's part of my question. Perhaps someone can come along and say "no, .Net will marshal it all, it must be some other problem" or "yes that's right you can't expect this to work from another thread" and hopefully someone will say "but here's how you could do it"

Resource file issue

George_George30-Dec-08 0:24

George_George

30-Dec-08 0:24

Hello everyone,

Is it possible to define resources (like messages in different language translations, different title for the same person in different application scenarios) into a separate file (DLL or some other forms are both fine)? So that when we code, we just need to care about message ID and developer could separate from what the message ID actually maps to different messages in different languages or different scenarios (message ID will map to different message during runtime in different application scenarios)?

thanks in advance,
George

Re: Resource file issue

Natza Mitzi30-Dec-08 5:02

Natza Mitzi

30-Dec-08 5:02

I think that I understand your Q. I dealt with an issue similar to what you are describing.
You can use resource files for the actual messages one per language (do this in the UI layer or presentation layer) and use an enum for error codes in the logical layer. implement a method that picks the correct message field and the resource manager will pick the language for you.

Natza Mitzi

Re: Resource file issue

George_George30-Dec-08 18:09

George_George

30-Dec-08 18:09

Thanks for your advice, Natza!

I think using satellite assembly could solve my issue. Smile | :)

regards,
George

Print Reports

zeeShan anSari30-Dec-08 0:09

zeeShan anSari

30-Dec-08 0:09

Hi,
i am working on fees management system,where i have task to print the fee voucher of whole class student,i created feesVoucher.rdlc it is a template of fees voucher. it also show the data of single student.But how to i print the whole student fees voucher by using of single report.please suggest me.
thanks

Re: Print Reports

Paddy Boyd30-Dec-08 0:44

Paddy Boyd

30-Dec-08 0:44

Create a new report, put what you have in the single report in a repeating area and change the dataset to select all the students.

Re: Print Reports

zeeShan anSari30-Dec-08 0:54

zeeShan anSari

30-Dec-08 0:54

according to you..."subreport" is solution??

Re: Print Reports

Paddy Boyd30-Dec-08 1:00

Paddy Boyd

30-Dec-08 1:00

That is one way to do it, but not necessary - you can write the report any way that you need to. Unless i have misunderstood your requirements?

Making Control of Form

Xmen Real 29-Dec-08 23:25

Xmen Real

29-Dec-08 23:25

i want to make a control of form, something like master form. eg. I added some pictures, labels in a form, now i want to use that form in every form in my app. So to do that i add a project, add pictures and labels in that form and set its output type to 'Control Library', built it and its reference in project but its not appearing in that namespace. Any idea ?

P.S. For confusion, I clear that I do not want to add it 'Add New Item' Dialog

thanks

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Re: Making Control of Form

rah_sin29-Dec-08 23:31

rah_sin

29-Dec-08 23:31

have u added that in the refrence of ur project in which u want it to use

rahul

Re: Making Control of Form

Tom Deketelaere29-Dec-08 23:45

Tom Deketelaere

29-Dec-08 23:45

When adding a reference to a project you don't see the 'members' off that reference (so you don't see the classes, forms,controls,...) in the solution explorer.

The way to do what you want is either create the form dynamicly (in code) or add a form to your project that inherits from you form in the referenced dll (add new item --> inherited form --> chose your form)

Re: Making Control of Form [modified]

Xmen Real 30-Dec-08 1:43

Xmen Real

30-Dec-08 1:43

dude listen, i've tried every way to put that form inside my project. But damn thing is that other classes and components are appearing just form isnt even the modifier is public.

Edit :
Found it.

modified on Tuesday, December 30, 2008 7:56 AM

Re: Making Control of Form

Abdul Rahman Hamidy30-Dec-08 9:41

Abdul Rahman Hamidy

30-Dec-08 9:41

the easy way u can use that control like other .Net Controls is simply a few steps as follows.
>Right Click on the ToolBox pane and select Choose Items...
>from Choose ToolBox Items Dialog refer to .Net Framework Components
>Click on Browse button and find the .dll of the Control Library "the one u created as a control"
>Click OK button.
now that control is available in the toolbox pane as other controls.

Abdul Rahaman Hamidy
Senior Student Student in Computer Science
Kabul, Afghanistan
Software Developer

how do we daclare an array in a struct?

dec8229-Dec-08 23:21

dec82

29-Dec-08 23:21

how do we daclare an array in a struct?
thanks

Re: how do we daclare an array in a struct?

N a v a n e e t h29-Dec-08 23:27

N a v a n e e t h

29-Dec-08 23:27