C# Discussion Boards - CodeProject

E6AD12-Sep-05 4:16

12-Sep-05 4:16

Dear All,

I am trying to call a function from an Intel dll that's originally written in C/C++.

It's original prototype is :
HIGHGUI_API IplImage* cvvLoadImage( const char* filename );

I have marshalled it as :
[DllImport("highgui.dll")]
[return : MarshalAs(UnmanagedType.Struct)]
unsafe public static extern IplImage * cvvLoadImage(string filename);

when I try to run it ,I get the following error.Does anyone know how can I fix that?

Error: Cannot take the address or size of a variable of a managed type ('IplImage')

I have marshaled the originally struct IplImage into :
[StructLayout(LayoutKind.Sequential)]
unsafe public struct IplImage
{
....
};

Best Regards,
E.A.

popup window

malak nour12-Sep-05 4:10

malak nour

12-Sep-05 4:10

i'm working in aproject doing something loke massenger of msn and i wanna form popup to the user when another message to the user
i do the code put the form show in normal way i wanna it
appear sequencly

Get index of the Column in dataset

zaboboa12-Sep-05 3:42

zaboboa

12-Sep-05 3:42

Hello,

I have a dataset, and I want to sum up the values from certain column to a certain column (for example, rom comumn 3 to column 7).

So, is there a way of getting the index of the column?
Sort of row[0][column].Index, or something like that?

Thank you

Re: Get index of the Column in dataset

KaptinKrunch12-Sep-05 8:41

KaptinKrunch

12-Sep-05 8:41

You could do something of the following....

int[] cols = {2,3,5};
int total = 0;
for(int x=0;x<=cols.length -1;x++)
total += row[0][cols[x]];

above code is untested!

Re: Get index of the Column in dataset

miah alom12-Sep-05 9:04

miah alom

12-Sep-05 9:04

//this is for each row
foreach ( DataRow row in this.dataTable1.Rows )
{
int sum = Convert.ToInt32(row[3]) + Convert.ToInt32(row[7]);
}

//if you know the row index then use this
int sum = this.dataTable1.Rows[1][3] + this.dataTable1.Rows[1][7];

Re: Get index of the Column in dataset

Tigerkatze13-Sep-05 22:43

Tigerkatze

13-Sep-05 22:43

Try it with this function:
dataset.Tables["TableName"].Columns.IndexOf("ColumnName");

PreviewWord

Anonymous12-Sep-05 3:15

Anonymous

12-Sep-05 3:15

Hi Please let me know how to open uneditable word document in windows form C#.net.

It just like preview of document in windows form.

Thanks

Re: PreviewWord

Mohamad Al Husseiny12-Sep-05 10:18

Mohamad Al Husseiny

12-Sep-05 10:18

If the file extensio is rtf open it in richtextbox if doc i don not know
but you can use Word object in your.net application

MCAD

IActiveDesktop

Anonymous12-Sep-05 2:48

Anonymous

12-Sep-05 2:48

Dear all
i do programming in a desktop application that puts html file on the desktop as a background and rearrange desktop icons and adjust the list view of the desktop and others...
after searching the internet , i found that the only way is to use the IActiveDesktop interface.
so my question is how to implement IActiveDesktop interface in C#?
thx all

Re: IActiveDesktop

Mohamad Al Husseiny12-Sep-05 10:14

Mohamad Al Husseiny

12-Sep-05 10:14

May this help IActiveDesktop[^]
and http://dynamic-sysop.co.nr/[^] then click code example

MCAD

-- modified at 16:16 Monday 12th September, 2005

Access create table from the app ...

Sharpoverride12-Sep-05 2:45

Sharpoverride

12-Sep-05 2:45

I need a way of creating a table insinde an Access database if that's possible using a command or some equal structure ?? Does anybody know how to achieve this ? Or into an MySQL database ?

Lazar Mihai

Re: Access create table from the app ...

Guffa12-Sep-05 3:09

Guffa

12-Sep-05 3:09

Check out the "create table" command in SQL.

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OpenFile and SaveFile dialogs change the current directory.

Sharpoverride12-Sep-05 2:41

Sharpoverride

12-Sep-05 2:41

I wish to know why OpenFile and SaveFile dialogs change the current directory.

And if there si a way to prevent this, or shoud I use the following methond : Directory.SetCurrentDirectory( path );

This is what I curently use, and wanted to know if there is some other way.

Lazar Mihai

Re: OpenFile and SaveFile dialogs change the current directory.

S. Senthil Kumar12-Sep-05 4:01

S. Senthil Kumar

12-Sep-05 4:01

That's how they are expected to behave. Instead of using CurrentDirectory, you can try using System.AppDomain.CurrentDomain.ApplicationDirectory or something similar.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: OpenFile and SaveFile dialogs change the current directory.

Dave Kreskowiak12-Sep-05 5:52

Dave Kreskowiak

12-Sep-05 5:52

Your code really shouldn't be depending on the current directory anyway. The general rule-of-thumb in programming is assume nothing!. What this means is you never assume that the file you want to access is in the current directory. Always use fully qualified path names and not just a filename when doing any kind of file access.

This also has other benefits. Say you put up a OpenFileDialog that changed the current directory. After the user picks a file, you try and put the current directory back to what it was. But, your code crashes, for whatever reason, before that can happen! The function ends up returning as failed, but not having restored the current directory. Now what? Your next file access is assuming (there's that word again Wink | ;)

) the current directory is correct when it's not, and your app ends up crashing a second time, then a third, forth, fifth, ...

Write your code so it defends itself against itself. Never assume anything is what you expect it to be.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

-- modified at 16:07 Monday 12th September, 2005

Re: OpenFile and SaveFile dialogs change the current directory.

Large Data File13-Sep-05 22:14

Large Data File

13-Sep-05 22:14

Use this:

<br />
System.Windows.Forms.OpenFileDialog dlgOpenFile = new System.Windows.Forms.OpenFileDialog();<br />
...<br />
dlgOpenFile.RestoreDirectory = true;<br />
DialogResult res = dlgOpenFile.ShowDialog();<br />

But listen to dave's answer, he is totaly right about assuming paths.

pinvoke a C++ struct to C#

Thomas van Veen12-Sep-05 2:27

Thomas van Veen

12-Sep-05 2:27

Hey,

Can anyone help me migrating the following struct to C# ? The problem is, that I don`t know how to migrate the union section inside of the struct.

<br />
typedef struct _IMAGE_SECTION_HEADER {  BYTE Name[IMAGE_SIZEOF_SHORT_NAME];  union {    DWORD PhysicalAddress;    DWORD VirtualSize;  } Misc;  DWORD VirtualAddress;  DWORD SizeOfRawData;  DWORD PointerToRawData;  DWORD PointerToRelocations;  DWORD PointerToLinenumbers;  WORD NumberOfRelocations;  WORD NumberOfLinenumbers;  DWORD Characteristics;<br />
} IMAGE_SECTION_HEADER, *PIMAGE_SECTION_HEADER;<br />

Thanks,
Tom
Confused | :confused:

Re: pinvoke a C++ struct to C#

Andy Moore12-Sep-05 13:00

Andy Moore

12-Sep-05 13:00

Tom,

You would do this

[StructLayout(LayoutKind.Explicit)]<br />
public struct _IMAGE_SECTION_HEADER<br />
{<br />
    [FieldOffset(0)]<br />
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = IMAGE_SIZEOF_SHORT_NAME)]<br />
    public byte[] Name;<br />
<br />
    [FieldOffset(IMAGE_SIZEOF_SHORT_NAME)]<br />
    public int PhysicalAddress;<br />
<br />
    [FieldOffset(IMAGE_SIZEOF_SHORT_NAME)]<br />
    public int VirtualSize;<br />
<br />
    ...<br />
<br />
}

You basically put the members of the union at the same offset in the structure.

I hope this helps.

Human beings were not meant to sit in little cubicles staring at computer screens all day, filling out useless forms and listening to eight different bosses drone on about about mission statements. -- Peter Gibbons

[Message Deleted]

sahithya harsha12-Sep-05 2:24

sahithya harsha

12-Sep-05 2:24

[Message Deleted]

Re: help me plz....

Dave Kreskowiak12-Sep-05 6:02

Dave Kreskowiak

12-Sep-05 6:02

sahithya harsha wrote:
STEGANOGRAPHY USING AUDIO FORMAT

sahithya harsha wrote:
i don hav enough idea in c# and am doing self study now.

sahithya harsha wrote:
having my review in two days i gotto show somethng

TWO DAYS?! If you have very little experience in C#, you're going to find this project impossible in the time frame you have. You have to be comfortable with the language before you start a project of this complexity.

You have such a limited time to learn the language, the data formats for any audio file format, what is acceptable to do in that format and what is not, the implementation in code of your algorithms, ..., the only things your going to show at this review is how you've learned how to bite off more that you can chew and what the consequences are.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

[Message Deleted]

sahithya harsha12-Sep-05 13:42

sahithya harsha

12-Sep-05 13:42

[Message Deleted]

Re: help me plz....

Dave Kreskowiak12-Sep-05 15:46

Dave Kreskowiak

12-Sep-05 15:46

Let me get this straight. You got the code for this off of this site. You have one month before you have to turn it in. The code you have is part of a 15 part series of articles on stenography. Your best source for information about the code is Corinna John. Afterall, she wrote it.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Hi , Is there any way to Get HTTP Headers of a Page other then HttpWebRequest

Tariq Rahim12-Sep-05 2:01

Tariq Rahim

12-Sep-05 2:01

hi
i need urhent response

Is there any other way to get HTTP Headers in C# by not using HttpWebRequest and Response Calssess i mean through xml or sockets
if yes

please tell me with code or refrence to code

Thanks
in Advacne

TaRiQ

Re: Hi , Is there any way to Get HTTP Headers of a Page other then HttpWebRequest

Guffa12-Sep-05 3:40

Guffa

12-Sep-05 3:40

What's wrong with a WebRequest?

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Re: Hi , Is there any way to Get HTTP Headers of a Page other then HttpWebRequest

Tariq Rahim12-Sep-05 3:54

Tariq Rahim

12-Sep-05 3:54

i m preparing a Request using WebRequest but cant find proper response

thats why i want to use another way to get the response

please tell me in deatail

Thanks

Tariq

TaRiQ

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