Dynamic load of objects and its effects - C# Discussion Boards

Re: Beginner Q: How to create a splash screen

Daniel Turini7-Nov-02 8:43

7-Nov-02 8:43

Create a form, remove the border, put a timer on it, in the Elapsed event, Close the form.

lazy isn't my middle name.. its my first.. people just keep calling me Mel cause that's what they put on my drivers license. - Mel Feik

Re: Beginner Q: How to create a splash screen

matthias s.8-Nov-02 0:29

matthias s.

8-Nov-02 0:29

Thanks for your answer, but:

1. you don't have control over the loading progress. What I wanted to do is to display the splash screen only as long as my form needs to load. No longer no shorter.

2. Another issue with those splash screens ist that they should stay on top of all windows in your application. If you do it a modal dialog, processing (loading the main form) will not continue as long as the form is shown, if you do it with .TopMost=true and .Show, you have it hanging over each and every application. As well not quite what I would need.

After giving the whole thing a good thought, I came to the point that the only solution is to spawn a new thread when the main window starts loading, show a form in this thread and stop the thread when I'm through with my stuff and the main wnd is ready to be shown.

Agree?

Thanks a lot,

Matthias

In theory, there is no difference between theory and practice. In practice, however, there is.

(unknown author)

Re: Beginner Q: How to create a splash screen

Ray Cassick8-Nov-02 8:16

Ray Cassick

8-Nov-02 8:16

Instead of setting your main form as the start up object, try creating a moudle (what ever they are called now) and put the sub main there. In there , display your spalsh screen, the display your main dialog. When the main dialog is done loading, kill the splash screen.

Serializing an Exception object

solidstore7-Nov-02 7:12

solidstore

7-Nov-02 7:12

Is it possible to serialize an Exception derived class? When I try to add an exception to a System.Messaging.Message object (which internally serializes the object to XML) I receive the following error:

System.InvalidOperationException: There was an error reflecting 'Send.DALException'. ---> System.InvalidOperationException: The property 'Source' on type 'System.Exception' cannot be serialized because it is decorated with declarative security permission attributes. Consider using imperative asserts or demands in the property accessors.

What does this mean? Can I get around it?

Re: Serializing an Exception object

Franz Pikal7-Nov-02 22:00

Franz Pikal

7-Nov-02 22:00

hi,
i use this exception class in my remoted components. this execption class is serializable and should help you with your problem.

[Serializable]
public class ComponentException: ApplicationException, ISerializable
{
public ComponentException()
{
}
public ComponentException(string message)
: base(message)
{
}
public ComponentException(string message, Exception inner)
: base(message, inner)
{
}
//Deserialization constructor.
public ComponentException (SerializationInfo info, StreamingContext context)
: base( info, context)
{

}
}

hope it helps
franz

Re: Serializing an Exception object

solidstore7-Nov-02 22:47

solidstore

7-Nov-02 22:47

Thanks for the reply. Message queuing must try to serialize the object differently to your project because I still get an error. Its complaining it cant reflect the class because of security? I just have a wizard created Windows Forms project and have done nothing with security. Am I missing something? Heres a quick sample of code:

<br />
System.Messaging.Message msgRequest = new System.Messaging.Message();<br />
DALException apex = new DALException("Database Error", inner);<br />
msgRequest.Body = apex;<br />
msgRequest.Label = "Test";<br />
requestQ.Send(msgRequest); // throws an exception<br />

System.InvalidOperationException: There was an error reflecting 'Send.DALException'. ---> System.InvalidOperationException: The property 'Source' on type 'System.Exception' cannot be serialized because it is decorated with declarative security permission attributes. Consider using imperative asserts or demands in the property accessors.

Re: Serializing an Exception object

Franz Pikal7-Nov-02 23:05

Franz Pikal

7-Nov-02 23:05

hm, apperently your problem is not with the serializer but with code access security.
there is a tutorial available in the online help focusing on declarativ and imperativ code access security: "ms-help://MS.VSCC/MS.MSDNVS/csref/html/vcwlkSecurityTutorial.htm#vcwlksecuritytutorialsuppressingsecurity" or type "Security Tutorial" in the search screen of the online help.

i didn't have time to look into code access security up to now, so i wont be much help on this topic. if you find a solution to this problem it would be great if you drop me a mail.

the help also states that a default XMLMessageFormater is used if you do not provide your own. perhaps you could write your own XmlMessageFormatter class and let the message queue use this one instead of the default.

cheers
franz

Dynamic load of objects and its effects

LongRange.Shooter7-Nov-02 3:46

LongRange.Shooter

7-Nov-02 3:46

Okay, I searched the message board and it looks like this is a new topic.
From the point of view of having code that does not require changes and compiles, I have had a few designs that really would work best if I can dynamically load a DLL. So this has led to a few questions:

1. Just what are the steps I have to take to dynamically load a DLL

2. In all cases, each DLL is an implementation of a template DLL (or an inheretance of a base class...just with a different name in each case. So we were thinking of creating reference to the base class, establishing an object of that type, but dynamically setting it to whichever DLL I want to load.

3. Has anyone done any testing to determine if a dynamic load via Reflection has as bad of a throughput effect as late binding in VB6?? (early binding having a performance edge of 1000 fold over late binding) I was thinking that since we are doing what I explained in point 2, that I would have the flexibility of 'late binding' in that I am loading one of n-fold objects, but with the speed of early binding since I have the base object defined.

I would appreciate any input on this topic!

Thanks, Michael

_____________________________________________
_{I have a tendancy to where my mind on my sleeve
I have a habit of losing my shirt...}

Re: Dynamic load of objects and its effects

Stephane Rodriguez.7-Nov-02 4:43

Stephane Rodriguez.

7-Nov-02 4:43

How can this be a new topic when you see the "how to make a plugin" thread just below ?

Back to real work : D-23.

Re: Dynamic load of objects and its effects

LongRange.Shooter7-Nov-02 5:46

LongRange.Shooter

7-Nov-02 5:46

I searched for dynamic load, created the thread, then read the stuff on plug-in. ooops.

_____________________________________________
_{I have a tendancy to where my mind on my sleeve
I have a habit of losing my shirt...}

Can't change textbox.text from code after binding to dataset!!!

cternek6-Nov-02 21:59

cternek

6-Nov-02 21:59

Hello!

I made following steps:
1) Created a Winform with DataForm-Wizard.
2) Now I created a Button next of one textbox. In this button i
open a findfile-form which returns a string. This string i want
to write into my textbox with:
textbox1.text = returnvalue

If I start my project now I clicked my button and choose a File.
After that I see that in my textbox1 the filename comes up.
Then I jump to the 2nd textbox which is bound to the same dataset.
After I changed the 2nd textbox the value of the first textbox change
automatically to null.

I searched some newsgroups for this problems and found some useful but
nothing which can help me!

A tip was to add the command "bindingcontext[].EndCurrentEdit()" after
the command "textbox1.text = returnvalue" but then i get the error-msg
that some fields of my dataset are null. So it looks like the i can only
make a "EndCurrentEdit" at the end before updating.

What can i do to update my textbox and also get the changes to the dataset!

Thanks

Christian

Process.id ?

imran_rafique6-Nov-02 10:07

imran_rafique

6-Nov-02 10:07

can any body tell Process.id propertey is an int32 in vc++.net managed code? am i right ?
in vc++ process id is in DWORD data taype
if i want to get Process id in DWORD How to type caste it in DWORD?

r00d0034@yahoo.com

Re: Process.id ?

leppie6-Nov-02 10:25

leppie

6-Nov-02 10:25

DWORD strictly speaking is UInt32. But you can you any data type with the same width. IOW UInt32 or Int32 or IntPtr on 32-bit systems.

Hope this helps Smile | :)

"I dont have a life, I have a program."

how to make a plugin

Asim N.6-Nov-02 8:04

Asim N.

6-Nov-02 8:04

hello
i want to know can i make a plugin using c sharp
can someone help me out.
ASIM

Asim

Re: how to make a plugin

leppie6-Nov-02 10:31

leppie

6-Nov-02 10:31

Yes

1. Define a common interface.
2. Let all plugins implement the interface.
3. Load plugins via Assebly.Load.
4. Instantiate plugins with Activator class.

Stick to that, and it will work. NOTE: plugins cant be unloaded unless they in a different AppDomain, but that is another beast altogether that I havent been able to figure out (maybe its time to try again with renewed knowledge).

Cheers Smile | :)

"I dont have a life, I have a program."

Re: how to make a plugin

Eric Gunnerson (msft)6-Nov-02 13:46

Eric Gunnerson (msft)

6-Nov-02 13:46

The dynamic loading is a lot of extra work. If you want to try this, you might want to read this column:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dncscol/html/csharp05162002.asp

Re: how to make a plugin

Philip Fitzsimons7-Nov-02 1:42

Philip Fitzsimons

7-Nov-02 1:42

clickty police - eric, i'm shocked Big Grin | :-D

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dncscol/html/csharp05162002.asp [^]

"When the only tool you have is a hammer, a sore thumb you will have."

Re: how to make a plugin

Philip Fitzsimons7-Nov-02 1:45

Philip Fitzsimons

7-Nov-02 1:45

eric, just a quick question...
when reading your article on using win32 api I remembered that vb use to have a file which had all the api declarations and constants defined so that vb programmers did not have to type them in.

is there going to be such a thing for c# - its too easy to translate and api call incorrectly....

thanks in advance Big Grin | :-D

"When the only tool you have is a hammer, a sore thumb you will have."

Re: how to make a plugin

James T. Johnson7-Nov-02 2:41

James T. Johnson

7-Nov-02 2:41

Somewhere on GotDotNet there is a VB program submitted which will take that file and produce the equivalent C#/VB.NET code for the DllImport.

Unfortunately that api file is so old that the few functions I wanted to use it for weren't in there Blush | :O

James
Sig code stolen from David Wulff

Re: how to make a plugin

Nnamdi Onyeyiri6-Nov-02 20:53

Nnamdi Onyeyiri

6-Nov-02 20:53

http://msdn.microsoft.com/msdnmag/issues/02/07/CuttingEdge/default.aspx[^]

1001111111011101111100111100101011110011110100101110010011010010
Sonork | 100.21142 | TheEclypse

Using Typed Datasets

afronaut6-Nov-02 5:17

afronaut

6-Nov-02 5:17

What is the main advantage of using a typed dataset? I am trying to model a bunch of data being inserted from several aspx pages and wondering if I should just have a basic class or if I should use a typed dataset and allow the data adapter to do the update for me.

My leaning at this point is not to use the typed dataset; there won't be any manipulation of data on the client side, I am rather building a row to do an insert into a table. There would be overhead associated with the dataset that I'm not convinced would be beneficial. Hm....

Any criteria anyone can think of?

Thanks much,

*->>Always working on my game, teach me
*->>something new.
cout << "dav1d\n";

Re: Using Typed Datasets

leppie6-Nov-02 10:36

leppie

6-Nov-02 10:36

afronaut wrote:
wondering if I should just have a basic class or if I should use a typed dataset and allow the data adapter to do the update for me.

Yes yes yes Smile | :)

SO much easier!

afronaut wrote:
My leaning at this point is not to use the typed dataset; there won't be any manipulation of data on the client side, I am rather building a row to do an insert into a table. There would be overhead associated with the dataset that I'm not convinced would be beneficial. Hm....

I use datasets generally for SELECT queries only. I ussually create my own SQL commands for INSERT UPDATE DELETE. The big plus point of a dataset is the ability to have very easy databinding, although using the DBReader is faster.

SO to conclude. Dataset ease of use, auto mapping. Reader speed, manual mapping and "casting".

Its up to you really. Smile | :)

Cheers

"I dont have a life, I have a program."

Re: Using Typed Datasets

Eric Gunnerson (msft)6-Nov-02 13:41

Eric Gunnerson (msft)

6-Nov-02 13:41

I've played around with both approaches, and I just wrote an app that had to do a bunch of different queries. It turned out that it was simpler for me to write a method that used a SQLCommand and a data adapter with textual SQL to fetch the data and process it instead of a strongly-typed dataset and a data adapter created in the data designer. The first one took a little while, but then I could easily generalize to the other queries.

The thing you lose is the strongly-typed feature, and the graphical query designer. The first is a bit of an annoyance, but I tend to use enterprise manager for queries anyway.

YMMV

uploading stream to webserver

Anonymous6-Nov-02 5:08

Anonymous

6-Nov-02 5:08

I try uploading a stream to a
textfile on a webserver. This is the code:

WebClient webClient = new WebClient();
Stream stream = webClient.OpenWrite
("http://localhost/accept/newfile.txt","PUT");
StreamWriter streamWriter = new StreamWriter(stream);
streamWriter.WriteLine("Hello world");
streamWriter.Close();

the example I am trying says the directory "accept" has to be writeable. I have tried various
permission settings but the webserver keeps saying it's unauthorized when
I run the example. Any ideas on what the proper settings should be ?

Re: uploading stream to webserver

Philip Fitzsimons7-Nov-02 1:39

Philip Fitzsimons

7-Nov-02 1:39

remember the webserver runs as a particular user - you need to give that user write permission to the directory you are trying to put the file in.

"When the only tool you have is a hammer, a sore thumb you will have."

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.