Re: MS-SQL connection (ADO) in C#? - C# Discussion Boards

imran_rafique29-Sep-02 15:55

29-Sep-02 15:55

thanks.
one more question.this line of code
formatter.Serialize(stream, obj);
alwas write data at the end of file or not ?
i mean there are alot of Objects .
where it write in the file?

this line of code
object obj = formatter.Deserialize(stream);
alwas read data from the begining of file or not ?
i mean there are alot of Objects.
where it read from the file?

r00d0034@yahoo.com

Re: HOW to creat FileStream?

Stephane Rodriguez.29-Sep-02 19:43

Stephane Rodriguez.

29-Sep-02 19:43

Most probably yes, each call to Serialize appends data at the end.
But in fact you need not care about it, that's internal implementation. You must only make sure that your own serialization/deserialization are dual, ie do exactly the same thing. For instance :

// serialize
formatter.Serialize(s, obj1);
formatter.Serialize(s, obj2);
formatter.Serialize(s, obj3);

// deserialize
formatter.Deserialize(s, obj1);
formatter.Deserialize(s, obj2);
formatter.Deserialize(s, obj3);

if you start putting in too manay features, it no longer remains useful for beginners
quote in a CP article comment, shiraz baig

matching types for COM server???

CherezZaboro28-Sep-02 10:41

CherezZaboro

28-Sep-02 10:41

I have MFC COM server with interface that has a method declared as
[id(1)] void TRYOUT(VARIANT* pv); in ODL and
void CI::TRYOUT(VARIANT FAR* pv) {...} in the implementation.
C# sees it as
void CI.TRYOUT (ref object pv);
So here what I do:

Object oRes= new Object();
oI.TRYOUT(ref oRes); // oI is referenced instance of CI

And I get exception - type mismatched.
What's wrong? Confused | :confused:

Please help!

Re: matching types for COM server???

Stephane Rodriguez.28-Sep-02 21:07

Stephane Rodriguez.

28-Sep-02 21:07

It seems from what you say that the compilation went fine, and it failed at run-time, right?

From my personal experiments, I would avoid to use VARIANT* because the marshaler does not know how to marshall all variant subtypes.

You may need to add a [MarshalAs...] attribute to bind to a specific subtype, especially if you know that VARIANT* references a BSTR for instance.

if you start putting in too manay features, it no longer remains useful for beginners
quote in a CP article comment, shiraz baig

Re: matching types for COM server???

CherezZaboro30-Sep-02 6:07

CherezZaboro

30-Sep-02 6:07

How do I use MarshalAs in Cleint app? Confused | :confused:

I looks like it's an attribute in interface declaration.

Also. How do you pass an array of longs backfrom MFC server to C# client without using VARIANT*?
And! How do you pass an array of strings from C# cleint to MFC server?

Re: matching types for COM server???

Stephane Rodriguez.30-Sep-02 6:13

Stephane Rodriguez.

30-Sep-02 6:13

you need not an interface declaration to put a MarshalAs attribute. Get used to it. You can put attributes ANYWHERE in your code.

you usually pass an array of long as a SafeArray.

You've got doc and sample code here [^]and here[^].

sometimes it helps to look at the IL generated code
a MS guy on develop.com "answering" .NET issues

MS-SQL connection (ADO) in C#?

Derek Smigelski28-Sep-02 10:09

Derek Smigelski

28-Sep-02 10:09

Can anyone tell me how to go about setting up and using an MS-SQL connection (ADO) in C#?

Thanks,
Derek

Re: MS-SQL connection (ADO) in C#?

Mazdak28-Sep-02 10:18

Mazdak

28-Sep-02 10:18

Maybe this help you:

http://www.codeproject.com/aspnet/adodotnet.asp[^]

Mazy

"If I go crazy then will you still
Call me Superman
If I’m alive and well, will you be
There holding my hand
I’ll keep you by my side with
My superhuman might
Kryptonite"Kryptonite-3 Doors Down

Need some newbie C# help. Need dock a form to another form.

Derek Smigelski28-Sep-02 9:58

Derek Smigelski

28-Sep-02 9:58

I create an app in C# and put my controls on right side. I intend to dock an Outlook type toolbar on the left. So inside the development I have two forms My original form NHN.cs and my outlook bar called OLBar.cs I want to doc the OLBar.cs to the left side of NHN.cs.

1) How is this accomplished.
2) The Outlook Bar code that I download from http://www.codeproject.com/cs/miscctrl/outlookbar.asp seems to be a nice
toolbar but for the life of me I can't get that docked to the left onto my NHN.cs form.

Has anyone used this Outlook toolbar that might be able to offer some help OR does anyone know another way to add an outlook toolbar on a form?

Many Thanks,
Derek
Derek@NeedHelpNow.com

Re: Need some newbie C# help. Need dock a form to another form.

Gaul28-Sep-02 13:08

Gaul

28-Sep-02 13:08

You basically need to use the DockStyle to position elements on a container type object.

You could create a panel to host your forms. Assuming Form1 is the one you want on the right side, you could do something like this:

panelRight = new Panel();
panelRight.Dock = DockStyle.Fill;
form1 = new Form1();
form1.Parent = panelRight;

panelLeft = new Panel();
panelLeft.Dock = DockStyle.Left;

splitter1 = new Splitter();
this.Controls.AddRange(new System.Windows.Forms.Control[]
{panelRight, splitter1, panelLeft});

The order of adding things to this.Controls above is important.

panelLeft could be the parent of your Outlookbar control.

Gaulles
http://www.gaulles.com

Re: Need some newbie C# help. Need dock a form to another form.

Luis Alonso Ramos30-Sep-02 4:16

Luis Alonso Ramos

30-Sep-02 4:16

Derek Smigelski wrote:
Has anyone used this Outlook toolbar that might be able to offer some

I have used it.

I use a panel (which I can change) that fills all the client area of my main window (panel.Dock = DockStyle.Fill).

Then I create a Splitter, assignig its parent as the main form, and set its Dock property to DockStyle.Left.

Finally I create the outlook bar, I assign its parent as the main form, and set its Dock property again to DockSytle.Left.

And there, you have a resizable Outlook bar on the left.

-- LuisR

──────────────
  Luis Alonso Ramos
  Chihuahua, Mexico
  www.luisalonsoramos.com

"Do not worry about your difficulties in mathematics, I assure you that mine are greater." -- Albert Einstein

Control.Invalidate()

Nnamdi Onyeyiri27-Sep-02 22:52

Nnamdi Onyeyiri

27-Sep-02 22:52

When the control calles this method on itself, and its scrollbars are showing, does this only paint the visible bit, or the non-visible bit as well?

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

Re: Control.Invalidate()

James T. Johnson28-Sep-02 5:02

James T. Johnson

28-Sep-02 5:02

You're going to hate this answer, but it paints whatever the control wants to paint.

Part of the Paint event tells it what part needs to be redrawn, but if the control ignores that it will attempt to redraw everything. The paint event is smart enough to set the clipping area so only the part that was supposed to be redrawn actually gets refreshed in the control.

James
Sig code stolen from David Wulff

can any body tell the syntex of reading and writing an object into file?

imran_rafique27-Sep-02 16:09

imran_rafique

27-Sep-02 16:09

if i have a class like
class{
String *str;
int a ;
}
i want to right its object into file.after that i want to send it to different computer through network and again want to read it again if i have the same class there may i read it into that class object.
is it possible ?
can any body tell the syntex of reading and writing an object into file?

r00d0034@yahoo.com

Re: can any body tell the syntex of reading and writing an object into file?

Nnamdi Onyeyiri27-Sep-02 22:49

Nnamdi Onyeyiri

27-Sep-02 22:49

if you want to serialize the object to file, you can use the BinaryFormatter class, in the System.Runtime.Formatters.Binary namespace. Which has two very handy functions to serialize and deserialize objects. Smile | :)

using System.Runtime.Formatters.Binary;
 
.....
 
// Write data to stream.
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(theStream, theObject);
theStream.Close();
 
// read data
BinaryFormatter bf = new BinaryFormatter();
theObject = bf.Deserialize(theStream);
theStream.Close();

Of course, theStream could be a NetworkStream to send datathrough networks, or a FileStream to read/write data to file, etc.

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

Re: can any body tell the syntex of reading and writing an object into file?

imran_rafique28-Sep-02 15:22

imran_rafique

28-Sep-02 15:22

A bundle of thanks.

i need a little more help how to write data using FileStream into a file or read theobject from a file to the FileStream object only then it is possible to serialize or Deserialize it?

HOW to creat FileStream object that coud write into a file ?
can you explain any of its constructor?

i want to write a hastable object into a file that contain class objects,and class objects further contain hashtable and other class objects.
may i write that hashtable into a file and retrive again?

i study the api but could not understand what methods to use.

r00d0034@yahoo.com

Re: can any body tell the syntex of reading and writing an object into file?

Nnamdi Onyeyiri28-Sep-02 22:46

Nnamdi Onyeyiri

28-Sep-02 22:46

im not quite sure what a hash table is, but im sure its held within one object. If you require to store more than one object in the file, simple create a structure that holds all the various types of information, and serialize that.

this is how you use FileStream

using System.IO;
using System.Runtime.Formatters.Binary;
...
public object LoadFile(string filename)
{
   Stream stream = new FileStream(filename, FileMode.Open);
   BinaryFormatter bf = new BinaryFormatter();
   object obj = bf.Deserialize(stream);
   stream.Close();
   return obj;
}

public void SaveFile(string filename, object data)
{
   Stream stream = new FileStream(filename, FileMode.Create);
   BinaryFormatter bf = new BinaryFormatter();
   bf.Serialize(stream, data);
   stream.Close();
}

Simple.

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

Re: can any body tell the syntex of reading and writing an object into file?

imran_rafique29-Sep-02 15:49

imran_rafique

29-Sep-02 15:49

thanks again.
one more question.this line of code
bf.Serialize(stream, data);
alwas write data at the end of file or not ?
i mean where it write in the file.

this line of code
object obj = bf.Deserialize(stream);
alwas read data from the begining of file or not ?
i mean where it read from the file.

r00d0034@yahoo.com

Re: can any body tell the syntex of reading and writing an object into file?

Nnamdi Onyeyiri29-Sep-02 20:59

Nnamdi Onyeyiri

29-Sep-02 20:59

im not sure, i presume it reads from where ever the current position, set in stream.Seek to the end of the file, but i cant swear to it.

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

VFW in C#

Jarrett Vance27-Sep-02 10:43

Jarrett Vance

27-Sep-02 10:43

Is it possible to call upon video for windows VFW in C#? Is there any existing code for compressing an AVI in C#? Thanks for any help or links you can provide.

Re: VFW in C#

Stephane Rodriguez.27-Sep-02 22:29

Stephane Rodriguez.

27-Sep-02 22:29

Anything you do with WIN32 and C/C++ is possible in C# thanks to interop.

When you know the method signature, you just need to declare it in your code with a [DllImport("dllname")] attribute like in ::SendMessage :

[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern IntPtr SendMessage(IntPtr hWnd, int msg, int wParam, IntPtr lParam);

Even more interesting is that in your case there are COM components. And the VS.NET IDE automatically imports their type-library, wrap interfaces and makes them look like any namespace to you. That's what you get for instance when you need integration with Internet Explorer, MS Office, ...

Now about DirectShow itself, this SDK has both COM Components and simple low-level APIs. Just help yourself. Below is 2 CP articles about it :
DirectShow media player[^]
DirectShow.NET[^]

You've got an introductory article about DirectShow in MSDN Mag - july 2002[^].

if you start putting in too manay features, it no longer remains useful for beginners
quote in a CP article comment, shiraz baig

Re: VFW in C#

Daniel Strigl29-Sep-02 20:15

Daniel Strigl

29-Sep-02 20:15

Take a look on DirectShow.NET.

--
Nice greets, Daniel.

Windows Form Designer

Nnamdi Onyeyiri27-Sep-02 8:38

Nnamdi Onyeyiri

27-Sep-02 8:38

Does anyone know how to make my control such that when it is displayed in the windows form designer, the grid does not appear over it???

[edit]
oh, and im not gonna ask if there is something specific i have to do to my collectionbase derived class, to make the windows forms designer use the collection properly Mad | :mad:

[/edit]

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

Re: Windows Form Designer

leppie27-Sep-02 9:15

leppie

27-Sep-02 9:15

Nnamdi Onyeyiri wrote:
oh, and im not gonna ask if there is something specific i have to do to my collectionbase derived class, to make the windows forms designer use the collection properly

You just need to implemenet an indexer Smile | :)

We had plenty disscussions about that during the last week. Have a look at the CollectionEditor class for more details, I'm still trying to figure out how to add multiple types, it sure did look easy Smile | :)

Cheers

PS: Where have u been?

Give them a chance! Do it for the kittens, dear God, the kittens!
As seen on MS File Transfer: Please enter an integer between 1 and 2.

Re: Windows Form Designer

Nnamdi Onyeyiri27-Sep-02 9:26

Nnamdi Onyeyiri

27-Sep-02 9:26

public class EBGroupCollection : CollectionBase
public EBGroup this[int index]
   {
    get
    {
     return (EBGroup)this.List[index];
    }

    set
    {
     this.List[index] = value;
    }
   }

   public EBGroupCollection()
   {
   }

   public void Add(EBGroup value)
   {
    this.List.Add(value);
   }

 }

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

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