Re: HOW to creat FileStream? - C# Discussion Boards

Re: Scrolling with the mouse wheel

29-Sep-02 5:34

my userControl derived control responds to the mouse wheel when the app starts, but as soon as the focus passes over to something else, the mouse wheel doesnt work, even after manually scrolling the bar, and clicking in the area of the control, to make sure it has focus, or is there something special needed to actually give it focus?

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

James T. Johnson29-Sep-02 6:04

James T. Johnson

29-Sep-02 6:04

Do you mean with or without the cursor positioned over the control?

If you mean with the cursor not over the control, thats just the way scrolling with a wheel works.

Take this browser window for instance; resize it so it only takes up half the screen, then place the cursor over the non-browser portion of the screen. If you move the mouse wheel the window will no longer scroll.

James
Sig code stolen from David Wulff

Re: Scrolling with the mouse wheel

Nnamdi Onyeyiri29-Sep-02 6:11

29-Sep-02 6:11

ok, im not stupid, i mean with the mouse over the control Poke tongue | ;-P

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

HOW to creat FileStream?

imran_rafique28-Sep-02 15:34

Re: HOW to creat FileStream?

28-Sep-02 15:34

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

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

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

Stephane Rodriguez.28-Sep-02 21:01

Re: HOW to creat FileStream?

28-Sep-02 21:01

[Serializable]
public class MyObject {
  public int n1 = 0;
  public int n2 = 0;
  public String str = null;
}

MyObject obj = new MyObject();
obj.n1 = 1;
obj.n2 = 24;
obj.str = "Some String";
IFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream("MyFile.bin", FileMode.Create, FileAccess.Write, FileShare.None);
formatter.Serialize(stream, obj);
stream.Close();

And of course, you've got a System.Collections.HashTable object to play with.

See here[^]

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

imran_rafique29-Sep-02 15:55

Re: HOW to creat FileStream?

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

Stephane Rodriguez.29-Sep-02 19:43

matching types for COM server???

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

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

Re: matching types for COM server???

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

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

MS-SQL connection (ADO) in C#?

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

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

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

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

imran_rafique27-Sep-02 16:09

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

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

Nnamdi Onyeyiri27-Sep-02 22:49

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

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."

imran_rafique28-Sep-02 15:22

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

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

Nnamdi Onyeyiri28-Sep-02 22:46

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

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."

imran_rafique29-Sep-02 15:49