passing HDC of picturebox to VC++ dll from C# - C# Discussion Boards

Sebastian Schneider8-Nov-04 0:37

8-Nov-04 0:37

the first string seems to be Base64-Encoded.

Look up Base64 in the MSDN, .NET has special classes to deal with this encoding. Try decoding the string using these classes.

compact framework Process.start

BoerPuillaert7-Nov-04 23:10

BoerPuillaert

7-Nov-04 23:10

Hi,

I want to start a process from my c# application for example

Process.Start("c:\Program Files\some_app.exe")

but Process.Start isn't supported in the compact framework, now I know you can use it by installing OpenNetCF but I don't want to do that.

Can anybody give me a good replacement for Process.Start?

Thnx

Davy

Enumerate Com ports

jk chan7-Nov-04 22:05

jk chan

7-Nov-04 22:05

Hi All

Is there any way to find the avilable COM ports in system ?
Pls reply ..

Thanks & Regards
Krishnan

If u can Dream... U can do it

Re: Enumerate Com ports

Valeria Bogdevich8-Nov-04 1:06

Valeria Bogdevich

8-Nov-04 1:06

the easiest way is to try to open any existing port. If the port exist but already in use, any attemt to open it will fail.
For more information about working with COM-ports make a search on MSDN looking for RS232 - a standard for serial communications.

"Absolution requires sacrifice" -- Dan Brown 'The Da Vinci code'

DropDownList1.SelectedIndex = -1 couldn't work ?

lighting_blue7-Nov-04 21:44

lighting_blue

7-Nov-04 21:44

DropDownList1.Items.Add ( "One" );
DropDownList1.Items.Add ( "Two" );
DropDownList1.SelectedIndex = -1;

why I still got One in my DropDown? I want got no selection.
Is there any property in dropdownlist muse be set?

Thankx

Re: DropDownList1.SelectedIndex = -1 couldn't work ?

Valeria Bogdevich8-Nov-04 0:40

Valeria Bogdevich

8-Nov-04 0:40

DropDownList1.Items.Add ( "" );
DropDownList1.Items.Add ( "One" );
DropDownList1.Items.Add ( "Two" );
DropDownList1.SelectedIndex = -1;
and after you have to call explicitly an event procedure for SelectedIndexChanged event because server-side event procedures requre a round trip to the Web server which doesn't happen if you change SelectedIndex value programmatically.

"Absolution requires sacrifice" -- Dan Brown 'The Da Vinci code'

Re: DropDownList1.SelectedIndex = -1 couldn't work ?

Anonymous8-Nov-04 19:19

Anonymous

8-Nov-04 19:19

hello mr
simply add
DropDownList1.Items.Add("")
DropDownList1.Items.Add("one")
.........

passing HDC of picturebox to VC++ dll from C#

handle1237-Nov-04 21:26

handle123

7-Nov-04 21:26

Hi,

plz plz help me i am struggling to display image in a picture box.. i am developing applicaiton where i have to call VC++ dll function to display image in picturebox of C# form.For that I should pass device context of picture box where i have to display image.But the problem is there is no device context for the picturebox....
I tried various method by converting picturebox to graphics object, and getting deivice context (objGfx.GetHdc()) and also pinvoke GetDC() (from user32.dll ) but to make my life miserable both are not working or I am making some silly mistake. Some sample code or link to the article where above problem is explaned will be helpful.

handle123

Re: passing HDC of picturebox to VC++ dll from C#

Corinna John7-Nov-04 22:08

Corinna John

7-Nov-04 22:08

Try passing the device context of the image:

<br />
//get HDC of the image in the box<br />
Image img = picturebox.Image;<br />
Graphics graphics = Graphics.FromImage(img);<br />
IntPtr hdc = graphics.GetHdc();<br />
<br />
//call VC++ function to paint the image<br />
//...<br />
<br />
//release HDC and Graphics<br />
graphics.ReleaseHdc(hdc);<br />
graphics.Dispose();<br />
<br />
//show the image<br />
picturebox.Refresh();<br />

_________________________________
nur Idioten brauchen einen Führer

Re: passing HDC of picturebox to VC++ dll from C#

handle1238-Nov-04 2:53

handle123

8-Nov-04 2:53

thanks for reply... I tried as you told but program is crashing at line

Graphics graphics = Graphics.FromImage(img);

because 'img' is undefined value and not set to anything because picturebox is empty initialy. Smile | :)

)

Re: passing HDC of picturebox to VC++ dll from C#

Corinna John8-Nov-04 3:39

Corinna John

8-Nov-04 3:39

Do you know the expected dimensions of the image?

<br />
//createn empty image<br />
picturebox.Image = new Bitmap(width, height);<br />

_________________________________
nur Idioten brauchen einen Führer

Re: passing HDC of picturebox to VC++ dll from C#

handle1238-Nov-04 4:28

handle123

8-Nov-04 4:28

I think i can use width and hieght of the picturebox.... i did the same but it is still not showing any image in picturebox... I am sending you the code snippet i have written.I am wiriting this code in the wndproc of the form ... I am not writing OnPaint()... ???

pictureBox1.Image = new Bitmap(pictureBox1.Height,pictureBox1.Width);
Image image = pictureBox1.Image;
gfx = Graphics.FromImage(image);
objFusion.m_hdc = gfx.GetHdc();

Int32 a = DrawLiveImage(objFusion.ConHandle,3,objFusion.m_hdc,ref rect);

if(a !=0)
{
MessageBox.Show(a.ToString());
}

gfx.ReleaseHdc(objFusion.m_hdc);
gfx.Dispose();

pictureBox1.Refresh();

here objFusion is the object where other VC++ dll calls are done and DVRDrawLiveImage is the function in a dll, this dll we are using to draw images in picture box which we are getting from Digital Video recorder.We get video image frames and we need to draw that in a picturebox.

database viewer

jomargon7-Nov-04 20:17

jomargon

7-Nov-04 20:17

good day.. jz wna know how i can show the list of tables in a database using listbox?? and once i click on a specific table, its contents will be shown on a datagrid.. btw, m using sql server.. thanks in advance!!

Re: database viewer

leppie7-Nov-04 21:39

leppie

7-Nov-04 21:39

Search for an article written by Christian Graus, should do every thing u need. There are many such things on the net too, just SEARCH Smile | :)

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Download xacc-ide 0.0.3 now!
See some screenshots}

C# Windows app in MFC

Member 169777-Nov-04 19:53

Member 16977

7-Nov-04 19:53

Hi,

Can we embedd the windows application created in C# .NET in MFC ActiveX Container application.

Thanks
TusharM.

help with system beep

tom_dx7-Nov-04 8:53

tom_dx

7-Nov-04 8:53

does anyone know the function for the system beep? i would appreciate the help, thx in advance Poke tongue | ;-P

IM PROUD TO BE A GMAIL;

Re: help with system beep

Colin Angus Mackay7-Nov-04 12:10

Colin Angus Mackay

7-Nov-04 12:10

tom_dx wrote:
does anyone know the function for the system beep?

I do. In fact, I even wrote an article about it.

A Simple Beep - Reminiscing about ZX Spectrum audio[^]

Do you want to know more?

Re: help with system beep

tom_dx7-Nov-04 13:10

tom_dx

7-Nov-04 13:10

thx

IM PROUD TO BE A GMAIL;

Re: help with system beep

Anonymous8-Nov-04 19:30

Anonymous

8-Nov-04 19:30

hello mr

like c and c++ , an 'escape sequences' available in c#.for instance
"\n" represents 'new line' that means it creates a new empty line and make cursor wait at starting of next line.
like wise in c# for beep u need to send an escape sequence for beep

in c#

console.writeline("this is beep" + "\t");
the beep sound can be heard after the message appeared

in vb.net

console.writeline("this is beep")
beep

Re: help with system beep

tom_dx9-Nov-04 1:29

tom_dx

9-Nov-04 1:29

im using whidbey and i found a function...
console.beep();
'and i thought it was \a for the beep Poke tongue | ;-P

IM PROUD TO BE A GMAIL;

BinaryReader I/O Problem - File Address

zuschauer7-Nov-04 8:22

zuschauer

7-Nov-04 8:22

Hi!

i read some data within a file. the data is an array of DWORDS (unsigned longs).
each DWORD is an pointer to data that is also within the same file.

Such pointer is a DWORD like i mentioned before. For example i get a value like this (HEX) 74150000 (DEZ) 1947533312.

My Problem is that the FileLength is only 6364. Maybe i understand this wrong?
have i only to take a part of the dword value as address?

thanks for hints!

Re: BinaryReader I/O Problem - File Address

leppie7-Nov-04 9:22

leppie

7-Nov-04 9:22

zuschauer wrote:
unsigned longs

Actually unsigned int in terms on .NET, so thats the extra data u reading (basically the start of the data). Use UInt32 reader.

^{top secret
Download xacc-ide 0.0.3 now!
See some screenshots}

Re: BinaryReader I/O Problem - File Address

zuschauer7-Nov-04 9:48

zuschauer

7-Nov-04 9:48

oh, sry.

i allready use ReadUInt32() and store the data in a variable of type uint.

Re: BinaryReader I/O Problem - File Address

Phil J Pearson8-Nov-04 1:11

Phil J Pearson

8-Nov-04 1:11

It looks like a byte-ordering problem. Your bytes 74 15 00 00 probably represent 0x00001574 (5492 decimal).

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Re: BinaryReader I/O Problem - File Address

zuschauer8-Nov-04 4:09

zuschauer

8-Nov-04 4:09

omg

Your are right. I forgot to convert from big to little endian!!!

Thank you!!!

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