Help With Nesting Classes In Library

[joey.powell@topscene.com]

I am writing a class that will do some binary file IO. The class will
need to read a header from the binary file, and it will also need to
read a varying number of records in the file. I currently have two main
methods: Open(string FilePath) and Close(). I would like to read all of
the data into variables whenever Open is called. I would like to have a
Header (sub?)class within the main class, and maybe a collection or
array for the records. The following is a snippet of what I have so
far...


=============== =========

using System;
using System.Collecti ons.Generic;
using System.IO;
using System.Text;

namespace MyNameSpace
{
public class MyClass
{
private FileStream fsMyFile;
private BinaryReader brMyFile;

public void Open(string FilePath)
{
fsMyFile = new FileStream(File Path, FileMode.Open,
FileAccess.Read Write);
brMyFile = new BinaryReader(fs MyFile);

Header.MyCode = 2;
}

public void Close()
{
brMyFile.Close( );
fsMyFile.Close( );
}

public static class Header
{
private static int _MyCode;
public static int MyCode
{
get { return _MyCode; }
set { _MyCode = value; }
}
}
}
}

=============== =========

I want to be able to reference this dll to other projects and then use
it like...

MyClass someclass = new MyClass();
someclass.Open( "[path to file]");
TextBox1.Text = (someclass.Head er.MyCode).ToSt ring();
someclass.Close ();

How can I get the someclass.Heade r.MyCode syntax to work? Will it not
work now because I am putting the header class inside the main class?
Are you confused as I am?

Any suggestions would be appreciated.

[Bruce Wood]

Re: Help With Nesting Classes In Library

joey.powell@top scene.com wrote:[color=blue]
> I am writing a class that will do some binary file IO. The class will
> need to read a header from the binary file, and it will also need to
> read a varying number of records in the file. I currently have two main
> methods: Open(string FilePath) and Close(). I would like to read all of
> the data into variables whenever Open is called. I would like to have a
> Header (sub?)class within the main class, and maybe a collection or
> array for the records. The following is a snippet of what I have so
> far...[/color]

You're right: there's some confusion here. I've made some notes
in-line.
[color=blue]
> using System;
> using System.Collecti ons.Generic;
> using System.IO;
> using System.Text;
>
> namespace MyNameSpace
> {
> public class MyClass
> {
> private FileStream fsMyFile;
> private BinaryReader brMyFile;
>
> public void Open(string FilePath)
> {
> fsMyFile = new FileStream(File Path, FileMode.Open,
> FileAccess.Read Write);
> brMyFile = new BinaryReader(fs MyFile);
>[/color]

The following line should compile fine. It doesn't matter that Header
is nested inside MyClass: you're just setting a static property of the
class Header to be 2.
[color=blue]
> Header.MyCode = 2;
> }
>
> public void Close()
> {
> brMyFile.Close( );
> fsMyFile.Close( );
> }
>
> public static class Header
> {
> private static int _MyCode;
> public static int MyCode
> {
> get { return _MyCode; }
> set { _MyCode = value; }
> }
> }
> }
> }
>
> =============== =========
>
> I want to be able to reference this dll to other projects and then use
> it like...
>
> MyClass someclass = new MyClass();
> someclass.Open( "[path to file]");[/color]

The difficulty with the following is that you're trying to use a static
class name as though it were a property name, and an instance property
at that. The first thing you have to decide is whether MyCode is an
instance-level thing (that is, there is one MyCode for each Header that
you create) or whether it's a static thing (that is, there is only one
MyCode in the entire program, no matter how many Headers or MyClasses
you instantiate). Once you have that sorted out, I can give you more
information on how to achieve what you want.

[joey.powell@topscene.com]

Re: Help With Nesting Classes In Library

There will be exactly one MyCode for the header. There is only one
header.

Bruce Wood wrote:[color=blue]
> joey.powell@top scene.com wrote:[color=green]
> > I am writing a class that will do some binary file IO. The class will
> > need to read a header from the binary file, and it will also need to
> > read a varying number of records in the file. I currently have two main
> > methods: Open(string FilePath) and Close(). I would like to read all of
> > the data into variables whenever Open is called. I would like to have a
> > Header (sub?)class within the main class, and maybe a collection or
> > array for the records. The following is a snippet of what I have so
> > far...[/color]
>
> You're right: there's some confusion here. I've made some notes
> in-line.
>[color=green]
> > using System;
> > using System.Collecti ons.Generic;
> > using System.IO;
> > using System.Text;
> >
> > namespace MyNameSpace
> > {
> > public class MyClass
> > {
> > private FileStream fsMyFile;
> > private BinaryReader brMyFile;
> >
> > public void Open(string FilePath)
> > {
> > fsMyFile = new FileStream(File Path, FileMode.Open,
> > FileAccess.Read Write);
> > brMyFile = new BinaryReader(fs MyFile);
> >[/color]
>
> The following line should compile fine. It doesn't matter that Header
> is nested inside MyClass: you're just setting a static property of the
> class Header to be 2.
>[color=green]
> > Header.MyCode = 2;
> > }
> >
> > public void Close()
> > {
> > brMyFile.Close( );
> > fsMyFile.Close( );
> > }
> >
> > public static class Header
> > {
> > private static int _MyCode;
> > public static int MyCode
> > {
> > get { return _MyCode; }
> > set { _MyCode = value; }
> > }
> > }
> > }
> > }
> >
> > =============== =========
> >
> > I want to be able to reference this dll to other projects and then use
> > it like...
> >
> > MyClass someclass = new MyClass();
> > someclass.Open( "[path to file]");[/color]
>
> The difficulty with the following is that you're trying to use a static
> class name as though it were a property name, and an instance property
> at that. The first thing you have to decide is whether MyCode is an
> instance-level thing (that is, there is one MyCode for each Header that
> you create) or whether it's a static thing (that is, there is only one
> MyCode in the entire program, no matter how many Headers or MyClasses
> you instantiate). Once you have that sorted out, I can give you more
> information on how to achieve what you want.[/color]

[joey.powell@topscene.com]

Re: Help With Nesting Classes In Library

I just want a logical way to oranize the information and to make it
accessible from function calls to the DLL.

I have one main file that contains a header and several, varying length
records.

I want to set it up so that I can create an instance of the class...

MyClass someclass = new MyClass();

and then call the open method...

someclass.Open( );

Once the open method is called I would like to be able to do things
like...

someclass.Heade r.ReadMyCode;
someclass.Heade r.WriteMyCode;

I can handle all of the code to do the reading and writing...I just
need to organize the classes, properties, etc... better.

Any suggestions appreaciated.


joey.powell@top scene.com wrote:[color=blue]
> There will be exactly one MyCode for the header. There is only one
> header.
>
> Bruce Wood wrote:[color=green]
> > joey.powell@top scene.com wrote:[color=darkred]
> > > I am writing a class that will do some binary file IO. The class will
> > > need to read a header from the binary file, and it will also need to
> > > read a varying number of records in the file. I currently have two main
> > > methods: Open(string FilePath) and Close(). I would like to read all of
> > > the data into variables whenever Open is called. I would like to have a
> > > Header (sub?)class within the main class, and maybe a collection or
> > > array for the records. The following is a snippet of what I have so
> > > far...[/color]
> >
> > You're right: there's some confusion here. I've made some notes
> > in-line.
> >[color=darkred]
> > > using System;
> > > using System.Collecti ons.Generic;
> > > using System.IO;
> > > using System.Text;
> > >
> > > namespace MyNameSpace
> > > {
> > > public class MyClass
> > > {
> > > private FileStream fsMyFile;
> > > private BinaryReader brMyFile;
> > >
> > > public void Open(string FilePath)
> > > {
> > > fsMyFile = new FileStream(File Path, FileMode.Open,
> > > FileAccess.Read Write);
> > > brMyFile = new BinaryReader(fs MyFile);
> > >[/color]
> >
> > The following line should compile fine. It doesn't matter that Header
> > is nested inside MyClass: you're just setting a static property of the
> > class Header to be 2.
> >[color=darkred]
> > > Header.MyCode = 2;
> > > }
> > >
> > > public void Close()
> > > {
> > > brMyFile.Close( );
> > > fsMyFile.Close( );
> > > }
> > >
> > > public static class Header
> > > {
> > > private static int _MyCode;
> > > public static int MyCode
> > > {
> > > get { return _MyCode; }
> > > set { _MyCode = value; }
> > > }
> > > }
> > > }
> > > }
> > >
> > > =============== =========
> > >
> > > I want to be able to reference this dll to other projects and then use
> > > it like...
> > >
> > > MyClass someclass = new MyClass();
> > > someclass.Open( "[path to file]");[/color]
> >
> > The difficulty with the following is that you're trying to use a static
> > class name as though it were a property name, and an instance property
> > at that. The first thing you have to decide is whether MyCode is an
> > instance-level thing (that is, there is one MyCode for each Header that
> > you create) or whether it's a static thing (that is, there is only one
> > MyCode in the entire program, no matter how many Headers or MyClasses
> > you instantiate). Once you have that sorted out, I can give you more
> > information on how to achieve what you want.[/color][/color]

[Bruce Wood]

Re: Help With Nesting Classes In Library


joey.powell@top scene.com wrote:[color=blue]
> I just want a logical way to oranize the information and to make it
> accessible from function calls to the DLL.
>
> I have one main file that contains a header and several, varying length
> records.
>
> I want to set it up so that I can create an instance of the class...
>
> MyClass someclass = new MyClass();
>
> and then call the open method...
>
> someclass.Open( );
>
> Once the open method is called I would like to be able to do things
> like...
>
> someclass.Heade r.ReadMyCode;
> someclass.Heade r.WriteMyCode;
>
> I can handle all of the code to do the reading and writing...I just
> need to organize the classes, properties, etc... better.
>
> Any suggestions appreaciated.[/color]

OK... so it looks to me as thought there is one Header _for each
MyClass_. That is, each instance of MyClass represents a file, and each
file has one header.

In that case you don't want Header to be a static member... you want it
to be an instance property of MyClass:

public class MyClass
{
private Header _header;
...
public class Header
{
private int _code;
...
public int MyCode { get { return this._code; } }
}
...
public Header Header
{
get { return this._header; }
}
}

Now you can say:

MyClass c = new MyClass();
int code = c.Header.MyCode ;

The problem is that you're using "static" where you shouldn't. If I
understand your problem correctly, there isn't just one header in you
whole program: there is one header per file. The fact that your program
may be reading only one file is incidental.