Help! help! Newbie... - C# Discussion Boards

suresh sahu5-Sep-05 21:53

5-Sep-05 21:53

Hi,

I have a problem in drawing lines.

I am drawing lines using mouse events when I draw the second line it will start from the end of the 2 line and when i draw the 3 line which should start from the second line but the problem is I CAN OVERWRITE the first line which should not happen AT ANY POINT OF TIME NO LINES SHOULD BE overlapped. When I press a key like 'C' the first line and the last line should coincide with out overlapping any line.

Plz do help me if u have any solution

Advance Thanks to all.

Regards
Suresh

Re: Drawing Lines

leppie6-Sep-05 3:43

leppie

6-Sep-05 3:43

And what does this have to do with C#? D'Oh! | :doh:

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DLL

kamlapuri5-Sep-05 21:45

kamlapuri

5-Sep-05 21:45

Hi I am using a third party dll in my project but now I want to use the updated version of this dll.How can I use this dll in dotnet.

Thanks & Regards
Pradeep Kr. Kamlapuri

Pradeep Kr. Kamlapuri
DotNet Programmer
Bhanusoft Tech Pvt Ltd
Noida

Re: DLL

S. Senthil Kumar6-Sep-05 2:19

S. Senthil Kumar

6-Sep-05 2:19

Just put the new DLL in place of the old DLL and you should be fine.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Dynamic Page Input

Expert Coming5-Sep-05 21:37

Expert Coming

5-Sep-05 21:37

I am creating a page dynamicly(using stringbuilder, then PageOut) I want to be able to dynamically name a button, then get input when that button is pressed. How do I do so?

Passing Variables

Expert Coming5-Sep-05 21:35

Expert Coming

5-Sep-05 21:35

How do I pass variables between aspx pages?

Example with CGI

http://www.dotcom.com/thepage.cgi?plugin=0&affiliate=marryweather&randval=213510766

So, how do I pass variables in a similar fashion?

Re: Passing Variables

shashank veerkar6-Sep-05 20:29

shashank veerkar

6-Sep-05 20:29

Hi Do this
Response.Redirect("mypage.aspx?id1=val1&id2=val2");
On the page mypage.aspx u can retrieve these values as follows
Request["id1"];
Request["id2"];

shashank

Help! help! Newbie...

boggs5-Sep-05 21:31

boggs

5-Sep-05 21:31

Does anyone know a library containing functions that directly decompresses a packed DIB that is a result of using "avifil32.dll's" AVIStreamGetFrame into a type Bitmap or any other type that a picture box could recognize. Thank you very much!!!

regards,
Raymond

Problem in moving the i mage

atifciit5-Sep-05 20:49

atifciit

5-Sep-05 20:49

Hello
I am doing a project in which i have to move a plane on the form from one side of the screen to the other. But the problem aries because i also have to play the sound parallel to it for this purpose i am using threads. I am moving the iamage by cahngeing the postion of the image but the movment is not uniform some time it stops for a whle and some time it moves on fastly.If any one know the solution plz let me know.

CPU serial number

Dr_C#5-Sep-05 20:37

Dr_C#

5-Sep-05 20:37

How can i get the CPU serial number or HDD , ...ets

Re: CPU serial number

Stanciu Vlad5-Sep-05 21:38

Stanciu Vlad

5-Sep-05 21:38

I think such informations are stored into the registres...
Try this key entry for a start "HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0"

I hope you understand...because is a rough world out there...

How can i make polar graph in .NET?

parvinder sehrawat5-Sep-05 20:29

parvinder sehrawat

5-Sep-05 20:29

Please help me for developing polar chart in .NET and what will be the parameters for polar chart and functionality?

Key Chord Sequences

Vasudevan Deepak Kumar5-Sep-05 20:08

Vasudevan Deepak Kumar

5-Sep-05 20:08

Visual Studio .NET uses bit of next level keyboard shortcut keys like KeyChord Sequences CTRL+K, CTRL \ etc.

I have a couple of questions thereto:

(*) In our Windows Forms too, is it possible to implement it by using Keyboard accelerator style itself or is it a Custom Key Press listener?

(*) Can this be used as a Global Shortcut key?

I think KeyChord Sequences would be definitely be a very unique key sequence to maintain keboard shortcuts for the applications.

Please advise...

Vasudevan Deepak Kumar
Personal Web: http://www.lavanyadeepak.tk/
I Blog At: http://deepak.blogdrive.com/

"For" bucle doesn't work in c#?

Heinz_5-Sep-05 20:03

Heinz_

5-Sep-05 20:03

Hi,

This sounds really crazy but a simple "for" instruction doesn't work in none of my programs.
The bucle is as follow:

for (int i = 0; i == 5; i++)
{
MessageBox.Show("Hello " + i);
}

I've tried this simple piece of code in every function i have, it compiles fine but at runtime it never get into the loop.
I'll try to reinstall the .NET FrameWork, reboot my PC, whatever. It's so simple but now it don't work. What could be possible wrong?

Thanx,

Heinz

Re: "For" bucle doesn't work in c#?

Stefan Troschuetz5-Sep-05 20:22

Stefan Troschuetz

5-Sep-05 20:22

The for-loop isn't entered, cause its condition (i==5) is never fulfilled.
Try i < 5 or i <= 5.

www.troschuetz.de

Resizing

dhanunjay5-Sep-05 19:08

dhanunjay

5-Sep-05 19:08

Hello

Please Solve my Problem

I have added an image using Transperency mode to Overlap two images. I got perfectly. But how can I resize that image? If i resize it the transperency is disappearing it is not resizing. Please help me in this

regards

dhanunjay

C# Nested Structure Marshalling

RobVai5-Sep-05 18:59

RobVai

5-Sep-05 18:59

I would like to declare the following structures in C# and be able to utilize the Marshal.StructureToPtr() and Marshal.PtrToStructure() on these structures and pointers later on. The reason being that I need structures that can be used for UDP packets that can be filled, sent, received, and later unpacked in the correct order.
In C++, these structures can be somewhat complex due to nested structures.

However, the example below is a very simple C++ nested structure with an attempted C# conversion. In the C#, I have only one query and that can be seen at the very end when transposing the last structure ie IDENTIFIER_T id[12];

Does anyone know a simple way to convert these simple structures to C#????

C++

typedef struct {
int source;
int destination;
int message;
}HEADER_T;

typedef struct {
double X;
double Y;
double Z;
}VECTOR_T;

typedef struct {
int id;
char[32] IdName;
int nameHashId;
}IDENTIFIER_T;

typedef struct {
int id;
char[64] dataName;
HEADER_T header;
VECTOR_T position;
IDENTIFIER_T id[12];
char[128] spare;
}DATA_T;

Attempted C# Equivalent

[ StructureLayout ( LayoutKind.Sequential ) ]
public struct HEADER_T {
int source;
int destination;
int message;
};

[ StructureLayout ( LayoutKind.Sequential ) ]
public struct VECTOR_T {
double X;
double Y;
double Z;
};

[ StructureLayout ( LayoutKind.Sequential ) ]
public class IDENTIFIER_T {
int id;
[ MarshalAs(UnmanagedType.ByValTStr, SizeConst=32 ]
string IdName;
int nameHashId;
};

public class DATA_T {
int id;
[ MarshalAs(UnmanagedType.ByValTStr, SizeConst=64 ]
string dataName;
HEADER_T header;
VECTOR_T position;

// ????? What happens here???? Confused | :confused:

IDENTIFIER_T id[12];

[ MarshalAs(UnmanagedType.ByValTStr, SizeConst=128 ]
string spare;
};

Rob

-- modified at 1:04 Tuesday 6th September, 2005

Re: C# Nested Structure Marshalling

leppie6-Sep-05 3:51

leppie

6-Sep-05 3:51

I think you can use the same as with strings. Look at UnmanagedType.ByValArray and specifiy the size.

Last resort, add 12 fields :p

To check size consistancy, do sizeof checks in both C and C#.

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Re: C# Nested Structure Marshalling

RobVai7-Sep-05 13:46

RobVai

7-Sep-05 13:46

Thanks but unfortunately the [MarshalAs(UnmanagedType.ByValArray , SizeConst=12)]will not work.
It compiles ok but will cause a runtime error because the MarshalAs can't determine the size of the structure.
SizeConst can only be specified for fundamental types and not for an array of structures. Sigh | :sigh:

-- modified at 19:50 Wednesday 7th September, 2005

Re: C# Nested Structure Marshalling

leppie7-Sep-05 14:16

leppie

7-Sep-05 14:16

RobVai wrote:
It compiles ok but will cause a runtime error because the MarshalAs can't determine the size of the structure.

After looking at your code again, it is because you are not using struct, some are class and some classes dont contain layout info, so the runtime will never be able to marshal that. Note: using a fixed layout class is making a pointer to a struct.

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Save a pictureBox object as JPEG or BMP?

boraxx5-Sep-05 18:25

boraxx

5-Sep-05 18:25

Hi,

I have a C# .NET framework 2.0 application that draws a bunch of lines and shapes by creating a Pen and a Graphics object and drawing the "art" onto a PictureBox.

Does anyone know how to save or export the drawn image as a bitmap or a jpeg?

This newbie would really appreciate some help with this question!

Thanks Smile | :)

Re: Save a pictureBox object as JPEG or BMP?

Andrew Kirillov5-Sep-05 19:09

Andrew Kirillov

5-Sep-05 19:09

Hello

Image image;

// BMP save
image.Save("image.bmp", ImageFormat.Bmp);
// JPEG save
image.Save("image.jpg", ImageFormat.Jpeg);

Andrew

Re: Save a pictureBox object as JPEG or BMP?

boraxx6-Sep-05 14:31

boraxx

6-Sep-05 14:31

Thanks for the quick response! However, I still can't get it to work. Here's my code:

<br />
            Pen myPen;<br />
            Graphics g;<br />
            myPen = new Pen(System.Drawing.Color.Red, 1);<br />
            g = pictureBox1.CreateGraphics();<br />
<br />
            g.DrawLine(myPen,1,1,30,30);  //Draw a line<br />
<br />
            //Try to save it but fails<br />
            Image image;<br />
            image = pictureBox1.Image;<br />
            image.Save(@"C:\image.bmp", System.Drawing.Imaging.ImageFormat.Bmp);

I get a NullReferenceExcetion was unhandled error. I'm not sure what that means... Frown | :(

Thanks much, Tim

Re: Save a pictureBox object as JPEG or BMP?

Andrew Kirillov6-Sep-05 18:57

Andrew Kirillov

6-Sep-05 18:57

Hello

Yes, it will fail. Because you did not initialize Image property of your picter box. If you need to save your drawing, you can use the next code:

Bitmap	image = new Bitmap(100, 100);
Pen	myPen = new Pen(System.Drawing.Color.Red, 1);
Graphics	g = Graphics.FromImage(image);

g.DrawLine(myPen,1,1,30,30); //Draw a line

myPen.Dispose();
g.Dispose();

// save image
image.Save(@"C:\image.bmp", System.Drawing.Imaging.ImageFormat.Bmp);

// display the image in picter box
pictureBox1.Image = image;

Andrew

Re: Save a pictureBox object as JPEG or BMP?

boraxx6-Sep-05 20:35

boraxx

6-Sep-05 20:35

THANKS MUCH, ANDREW Big Grin | :-D

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