How to Open file which length is 2^32 bytes - C# Discussion Boards

6-Jun-07 13:39

Convert ? No. Create an image and draw the path onto it.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Browsing a .dll file.

Ylno6-Jun-07 12:21

Ylno

6-Jun-07 12:21

Hello,

sorry, second post tonight, i feel like i'm flooding this board !

This is probably going to sound really stupid: Is a .dll file just a class?
Is it possible to browse the .dll file and see what Methods is provides?

BACKGROUND :

I just saw how to make my computer Beep via P/Inovke using the following code:

        <br />
[DllImport("kernel32.dll")]<br />
        public static extern bool Beep(int freq, int duration);<br />

From what i gather, we need to go via this route because the .NET doesn't provide
functionality for sound. What i'm thinking now is that there must be loads of other things
that the .NET can't do and how would i go about finding out what else is out there? (other than having been a programmer since before the .NET )

I tried adding a reference to the kernel32.dll, with the mind that then i might be able to 'view it's contents' using the object-browser but i got an error.

Thanks ..

Christian Graus6-Jun-07 12:36

6-Jun-07 12:36

Ylno wrote:
sorry, second post tonight, i feel like i'm flooding this board !

LOL - that's hardly flooding.

Ylno wrote:
From what i gather, we need to go via this route because the .NET doesn't provide
functionality for sound

Not entirely true, I thought .NET 2.0 had some sound functionality, to play wave files at least. And you can play most file formats with the media player control. It *is* true that p/invoke is the way to call APIs that give you things .NET does not.

Ylno wrote:
I tried adding a reference to the kernel32.dll, with the mind that then i might be able to 'view it's contents' using the object-browser but i got an error.

You can only do that with .NET dlls. p/invoke is for dlls that are not.

A dll is a bunch of code without an entry point, basically. www.pinvoke.net[^] provides signatures for calling lots of Win32 API methods and probably comes close to giving you a complete list of what's in those dlls, and what they are called.

Ylno6-Jun-07 12:44

Ylno

6-Jun-07 12:44

Cheers Christian,

That is exactly what i wanted. Thanks !

One thing :

Christian Graus wrote:
A dll is a bunch of code without an entry point,

I guess your referring to the Main() method. Does this mean basically that these files have usable code within but not are not in themselves excecutable?

Are the .dlls be written in C ? if so would that mean that their code could be viewed in a C compiler?

Christian Graus6-Jun-07 13:43

6-Jun-07 13:43

Ylno wrote:
Does this mean basically that these files have usable code within but not are not in themselves excecutable?

Some dlls just contain resources. Most contain code, but no way to execute that code, nothing that can run without being called. So, they contain typically libraries that you reference and call from your main program.

Ylno wrote:
Are the .dlls be written in C ?

Yes, in this case.

Ylno wrote:
if so would that mean that their code could be viewed in a C compiler?

No, C# and VB.NET are different to C, C compiles down to machine code and cannot be decompiled to readable code, at least not in the way that .NET code can.

How to Open file which length is 2^32 bytes

Ylno7-Jun-07 12:00

Ylno

7-Jun-07 12:00

Thank you again,

You've cleared somethings up in my mind.

Hesham Yassin6-Jun-07 11:10

Hesham Yassin

6-Jun-07 11:10

I tries to open file big than 2^32 bytes. it's not working because it pass the maximum addressing in the memory and it stucks the computer. is there a solution for that problem?????? Dead | X|

Guffa6-Jun-07 11:39

Guffa

6-Jun-07 11:39

There should be no problem opening the file. Are you saying that you are trying to read the entire file into memory?

If so, then the solution is simple: Don't. Just read the part of the file that you are currently working with.

---
single minded; short sighted; long gone;

Dave Kreskowiak6-Jun-07 11:47

Dave Kreskowiak

6-Jun-07 11:47

>4GB?? You're never going to read the entire file into memory. You have to process it piece by piece.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Judah Gabriel Himango6-Jun-07 12:47

Judah Gabriel Himango

6-Jun-07 12:47

As long as you're running NTFS, you should be able to open the file. You can't read it all into memory, of course; that's what FileStream [^]is for: read in small chunks at a time.

Tech, life, family, faith: Give me a visit.
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Is it true there is no text parsing in C#?

Hesham Yassin7-Jun-07 0:39

Hesham Yassin

7-Jun-07 0:39

computer cannot run this line if i try to open file bigger than 4GB

fs = File.OpenRead(path)

but the question, how can i open it in pieces? Confused | :confused:

jblouir6-Jun-07 11:00

6-Jun-07 11:00

I just read an article on parsing in c# and they said that unlike older languages, parsing in c# in simple terms, for a beginner, can be a nightmare.

All I want to do is store room descriptors in a text file with a dillimeter and a value.

- The first value is used to find the correct line to print. e.g 01
- The second part being the name of the room, or unless its the rooms look value, e.g 011
- The third part being the description of your initial impression before looking closer.

Data in the text file...

01,WestHall,The room is filled with old pottery and cobwebs.:
011,Searching the room you notice a hole where a key might fit.:

02,EastHall,Several torches line the walls, and a chest rests upon a stone slab in the back.:
021,Searching the room you notice the flames on the torches are not moving, almost as if...:

Is it possible to pull this data out in chunks using StreamReader?

Unless... I just thought of something as I write this very moment.

Can I say...

ReadToEnd, this entire text file and say drop it in to a string variable.

Then from their use some sort of character searching in the string?

Thanks for your help ahead of time. Smile | :)

Christian Graus6-Jun-07 11:39

6-Jun-07 11:39

jblouir wrote:
they said that unlike older languages, parsing in c# in simple terms, for a beginner, can be a nightmare.

Written by a moron then. The string class in C# has similar methods to CString in C++, it's at least as good as that class. It can be difficult to learn regex, but that's a moot point. You don't have to use regex, and if you do need it, it's wonderful that it's there.

jblouir wrote:
All I want to do is store room descriptors in a text file with a dillimeter and a value.

The string's split method will let you take a line and turn it into an array of strings, with each string being one of your values.

string [] lines = File.ReadAllLines(@"c:\file.txt");

foreach (string line in lines)
{
string [] elements = line.split(new char [] { ',' } );

if (elements.Count > 0)
{
int n;

if (int.TryParse(elements[0], out n))
{
// the first element was a number, now stored in n
}
}

if (elements.Count > 1)
{
// process elements[1], which is WestHall in the first instance.
}

// etc.
}

Dave Kreskowiak6-Jun-07 11:46

Dave Kreskowiak

6-Jun-07 11:46

Damn, you beat me to it! Frickin' router problems!

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Christian Graus6-Jun-07 12:15

6-Jun-07 12:15

ROTFL - you're usually the one who beats me :P

Dave Kreskowiak6-Jun-07 11:44

Dave Kreskowiak

6-Jun-07 11:44

jblouir wrote:
I just read an article on parsing in c# and they said that unlike older languages, parsing in c# in simple terms, for a beginner, can be a nightmare.

Anything for a beginner is a nightmare, until they learn it's really very easy! I have no idea where you read that, but stop.

jblouir wrote:
Is it possible to pull this data out in chunks using StreamReader?

Sure. But, you don't have to use ReadToEnd. Just read a line of the file (StreamReader.ReadLine), split the line on your delimitter (String.Split) to get the string values in an array, then process the first item in the array. That will tell you how many more items there should b in the array and what to do with them. Read the next line in the file. Rinse and Repeat.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

PIEBALDconsult6-Jun-07 13:07

PIEBALDconsult

6-Jun-07 13:07

The other responses are correct, but have you considered using XML?

jblouir6-Jun-07 14:47

6-Jun-07 14:47

I am trying to start with basic stuff, instead of jumping into 2d/3d graphics and using databases, so im just making a text adventure (In console) with simple data files for storing data, I might use serialisation for saving the game state(save games).

After that then ill move up to the fancier code. Blush | :O

)

Update, so far so good, just 1 error when running.

Ravi Bhavnani6-Jun-07 17:54

Ravi Bhavnani

6-Jun-07 17:54

jblouir wrote:
so im just making a text adventure (In console)

Splendid! Splendid! Check out Collosal Cave Adventure[^] Cool | :cool:

if you haven't already played it.

/ravi

This is your brain on Celcius
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com

jblouir6-Jun-07 14:34

Re: Update, so far so good, just 1 error when running.

6-Jun-07 14:34

Thanks for your help previously, been implementing it into my code.

Its changed a bit because I had problems with getting the .Count to work, doesnt appear to be in my namespaces.

but anyway heres what I have, the program doesnt get any syntax errors, but during the program running I get an error that...(scroll down)

#region dataload()
// Extracting the data from databin and dumping it in to an array.
static void dataload()
{
int intIndex = 0;
string strRoom = "anything";
string strDesc = "anything";
string strLook = "anything";
int intElement = 0;
int i = 0;

string[] lines = File.ReadAllLines("databin.txt");

foreach (string line in lines)
{
string[] elements = line.Split(new char[] { ',' });

intElement = elements.Length;

if (intElement > 0)
{
int n;

if (int.TryParse(elements[0], out n))
{
// the first element was a number, now stored in n
intIndex = n;
}
}

if (intElement > 1)
{
strRoom = elements[1];
}

if (intElement > 2)
{
strDesc = elements[2];
}

if (intElement > 3)
{
strLook = elements[3];
}

RoomData descriptor = new RoomData(intIndex, strRoom, strDesc, strLook);
GlobalVars.ArrRoomData.SetValue(descriptor,i);

i = i++;

// etc.
}
}
#endregion

the error points to GlobalVars.ArrRoomData.SetValue(descriptor,i); saying that the object reference not set to an instance of an object

ArrRoomData is declared in a class called GlobalVars (Global Variables), where...

private static object[] arrRoomData;

public object[] ArrRoomData
{
get { return arrRoomData; }
set { arrRoomData = value; }
}

I have a feeling that once it gets past this error im going to get another one on the fact that its going to try and declare another object named descriptor, which im guessing I can I can do an if check on a boolean to see if its already been declared once.

Christian Graus6-Jun-07 15:12

Re: Update, so far so good, just 1 error when running.

6-Jun-07 15:12

It's perhaps intElement.Length

jblouir wrote:
string strRoom = "anything";
string strDesc = "anything";
string strLook = "anything";

This is outside your loop, so if a row fails, instead of a default, it will continue to contain the last value found.

jblouir wrote:
saying that the object reference not set to an instance of an object

Odds are that a line doesn't have enough elements, and removing Count is making a check that is just invalid.

jblouir6-Jun-07 21:38

How to custom TrackBar in WinForm c# ?

6-Jun-07 21:38

At the bottom of the code where the particular code of line is highlighted.

descriptor is holding the correct values for index, room name, room desc, and room look.

The .Count I got around by using .Length which returns the number of elements in that line which logically to me does the same thing.

Epsilone36-Jun-07 10:23

Epsilone3

6-Jun-07 10:23

I Want to make the background and the tracker with images I've got.
There any dll that I can add my WinForm Controls ?

Thank alot.

Re: How to custom TrackBar in WinForm c# ?

Christian Graus6-Jun-07 10:41