Help With Nesting Classes In Library


J

joey.powell

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.Collections.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(FilePath, FileMode.Open,
FileAccess.ReadWrite);
brMyFile = new BinaryReader(fsMyFile);

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.Header.MyCode).ToString();
someclass.Close();

How can I get the someclass.Header.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.
 
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B

Bruce Wood

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...

You're right: there's some confusion here. I've made some notes
in-line.
using System;
using System.Collections.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(FilePath, FileMode.Open,
FileAccess.ReadWrite);
brMyFile = new BinaryReader(fsMyFile);

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.
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]");

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.
 
J

joey.powell

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

Bruce said:
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...

You're right: there's some confusion here. I've made some notes
in-line.
using System;
using System.Collections.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(FilePath, FileMode.Open,
FileAccess.ReadWrite);
brMyFile = new BinaryReader(fsMyFile);

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.
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]");

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.
 
J

joey.powell

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.Header.ReadMyCode;
someclass.Header.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.


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

Bruce said:
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...

You're right: there's some confusion here. I've made some notes
in-line.
using System;
using System.Collections.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(FilePath, FileMode.Open,
FileAccess.ReadWrite);
brMyFile = new BinaryReader(fsMyFile);

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.
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]");

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.
 
Ad

Advertisements

B

Bruce Wood

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.Header.ReadMyCode;
someclass.Header.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.

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.
 

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