Managed C++/CLI

Re: How to send double value as 8 uint8 values??

16-Aug-06 2:25

Yes, binary operations only work with integers. Multiply by whatever number of decimals you want, then cast to int. BTW, this is the wrong forum, this is not a managed C++ question

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

cahit2316-Aug-06 2:51

cahit23

16-Aug-06 2:51

oh sorry, i deliver my message in visual c++ forum then!

Graphics::FromImage

yiwpyos16-Aug-06 1:14

yiwpyos

16-Aug-06 1:14

Hello!

I'm trying to use double buffering to display some graphics faster on a pictureBox. I tried to use the setStyle property of the PictureBox the following way

pictureBoxMap->SetStyle(ControlStyles::UserPaint, true);
pictureBoxMap->SetStyle(ControlStyles::AllPaintingInWmPaint, true);
pictureBoxMap->SetStyle(ControlStyles::DoubleBuffer, true);
pictureBoxMap->UpdateStyles();

But no success...

Then i tried using the GDI+ method by drawing the graphics in a bitmap image first and then displaying the image on screen as follows

private: System::Void pictureBoxMap_Paint(System::Object *sender,System::Windows::Forms::PaintEventArgs *e)
{
Graphics *grOnPaint = e->Graphics;
Bitmap *bmpBuf = new Bitmap(ClientRectangle.Width,ClientRectangle.Height);
Graphics *bmpgr = Graphics::FromImage(bmpBuf);
Pen *BluPen = new Pen(Color::FromArgb(0, 0, 0, 255),50);

bmpgr->DrawLine(BluPen,10,10,100,100);

grOnPaint->DrawImage( bmpBufr,100,100);

bmpBuf->Dispose();
bmpgr->Dispose();

My question relates to the later method. It seems that "bmpgr" does not get created properly through Graphics::FromImage with the result "bmpBuf" to be empty and nothing to be drawn on my PictureBox.

Does anyone how i can do this properly? Or may what i am doing wrong with the pictureBoxMap->SetStyle() method.

Any comments would me most appreciated.

Thanks

george

george

Re: Graphics::FromImage

Christian Graus16-Aug-06 2:28

16-Aug-06 2:28

yiwpyos wrote:
nothing to be drawn on my PictureBox.

Why do you need a picture box if you're going to paint it yourself ? Just draw it onto your form.

That is how you use Graphics::FromImage, but you don't need it. Just draw your blue line onto grOnPaint instead.

DrawImageUnscaled is faster, if you're not scaling it anyhow.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

Re: Graphics::FromImage

yiwpyos16-Aug-06 22:39

yiwpyos

16-Aug-06 22:39

Hi Christian,

Thanks for your reply. The truth is that my drawing function is a lot more complicated than the example i showed in my message. I am going through three "for" loops to display 3D dispersions on a map.

I chose to use a pictureBox because i thought it would be easier to handle the map displaying (zooming in/out, panning etc) by specifying it as the pictureBox->image, and then drawing the rest on top and following the same zooming, panning etc. Not sure it is the best way to go about it, just chose it.

To cut a long story short, apart from removing the flickering from my drawing i wanted to use double buffering to also improve the speed of my displays because these are displayed in real time (would like to anyway Smile | :)

every 10 seconds). I did manage to implement the GDI+ double buffering i was straggling with (amazingly enough i was drawing in "bmpBuf" and was displaying "bmpBufr" >:E). However, although the flickering went away the displaying speed did not improve enough.

Do you think the .NET way of handling double buffering would do better (i read that the .NET way is more optimized http://www.windowsforms.net/articles/windowsformspainting.aspx). Any help how do make this work? This is what i tried

pictureBoxMap->SetStyle(ControlStyles::UserPaint, true);
pictureBoxMap->SetStyle(ControlStyles::AllPaintingInWmPaint, true);
pictureBoxMap->SetStyle(ControlStyles::DoubleBuffer, true);
pictureBoxMap->UpdateStyles();

Or any other suggestion how to improve the displaying speed would be much appreciated.

Thanks

george

george

Re: Graphics::FromImage

Christian Graus16-Aug-06 22:42

Receiving A Byte Array from dll? [modified]

16-Aug-06 22:42

Yes, you need to draw it yourself and turn on double buffering. Always use provided code first, assume a library author has been paid to take the time to provide the best possible implimentation.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

majidbhutta15-Aug-06 23:52

majidbhutta

15-Aug-06 23:52

Hello All!

I have been unable to receive a Byte[] in MC++. Whats the right syntax

this is the C# dll method.

public byte[] GetPictureBytes(Image _Pic)
{
byte[] _rtval = null;

MemoryStream mstr = new MemoryStream();

_Pic.Save(mstr, ImageFormat.Jpeg);

_rtval = mstr.GetBuffer();

return _rtval;
}
Now i have to call this C# dll method in VC++.NET 2005

the syntax that i m using to call and receive this byte array is as follows but its creating some error.
"
array<byte^>^ myImage = gcnew array<byte^>^(1);
myImage = dllobj->GetPictureBytes(_myImage);
"
OR
"array<byte^>^ myImage = gcnew array<byte^>^(1);
myImage = dllobj->GetPictureBytes(_myImage);"
// dllobj is of C# dll Class type that contains metod GetPictureBytes(Image _Pic);
// _myImage is Image type

i have used some other combinations also to receive the Byte array but cant having some errors. Plz guide me writing correct syntax to receive this Byte array in VC++.Net
THNX in Advance

-- modified at 5:55 Wednesday 16th August, 2006

pixil detection?

Droze15-Aug-06 6:36

Droze

15-Aug-06 6:36

hello friends;
I am currently trying to write a program that would detect if the colour red.
Basically i need to be able to set it up to monitor a certain portion of my screen (ie, bottom left, box shape) and when it detect a certian chape of red, it will return 1 or 0, or any type of return.

If this is to complicated to explain or to logn to quickly write a short code for it, i understand and thank you for your time in reading this post.

Thank you.

- Droz -
___ ___
/\/\ /\ | |

Re: pixil detection?

Jun Du17-Aug-06 5:15

Jun Du

17-Aug-06 5:15

To read/set the color of a pixel, there are two Win32/GDI calls, GetPixel() and SetPixel(). Try to find counterparts in managed GDI+. Otherwise, you may have to platform invoke Win32.

Best,
Jun

Re: pixil detection?

Droze17-Aug-06 10:56

Droze

17-Aug-06 10:56

Thank you Jun,
i'll look into those functions, thank you.

- Droz -
___ ___
/\/\ /\ | |

Fax Routing, Please Help

a_kiani15-Aug-06 2:16

a_kiani

15-Aug-06 2:16

I want to register a sample fax routing dll on Windows XP,
I have found this sample DLL from Windows SDK.
I can not register it, while on Windows 2000 it can be registerered.
On Windows XP the error message is:
"The modem did not accept the command sent to it. verify the configured modem
matches the attached modem."
Anyone could help me plase?

Re: Fax Routing, Please Help

Milton Karimbekallil15-Aug-06 18:22

How can i use dll function in c++.net ? please help .

15-Aug-06 18:22

This is a C++/CLI forum. Below given forums are more appropriate for these kind of questions.
http://www.codeproject.com/script/comments/forums.asp?forumid=186301[^]
or
http://www.codeproject.com/script/comments/forums.asp?forumid=1644[^]

Check whether the modem is installed properly in XP. This can be verified under "Device Manager".

cheers..Milton KB

nattafy15-Aug-06 1:39

nattafy

15-Aug-06 1:39

I have DirectX.Capture .dll file and i want to use function in dll but i don't know how to use .dll function in c++.net .
dll function from article 's DirectX.Capture .

Re: How can i use dll function in c++.net ? please help .

guestcat17-Aug-06 0:44

guestcat

17-Aug-06 0:44

simply #include the header file and
put the .lib file in the linker section.

if u do not have the header file but you know the signature
then use [DllImport] to call the methods from the dll.
first one is the easiest way.

^-^
@|@
- redCat

How to stop USB Mass Storage Device window popping out

mmhu11-Aug-06 4:35

Re: How to stop USB Mass Storage Device window popping out

11-Aug-06 4:35

Each time when I plug in USB memory stick to the pc, there is a window pops out. I have application to indicate whether a USB memory stick presents.I don't want this auto window to pop out. How shall I resolve it??

Christian Graus14-Aug-06 18:26

Re: How to stop USB Mass Storage Device window popping out

14-Aug-06 18:26

Well, you could buy a Mac...

Seriously, how does this have anything to do with programming, let alone C++/CLI ?

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

mmhu15-Aug-06 11:07

How to use WndProc or WindowsProc function

15-Aug-06 11:07

Uhm..
This is the problem encountered during programming.
I thought there would be some script can be used to solve it.
Anyway, I fund the solution. OMG | :OMG:

mmhu9-Aug-06 6:45

9-Aug-06 6:45

I'm writing VC++ .net framework code.
I need to retrieve the windows WM_DEVCHANGE message

Shall I use virtual void WndProc( Message* m ) override function or LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) function??

How shall I add either of them to my Form class???
May you write down the format?

Milton Karimbekallil10-Aug-06 22:57

10-Aug-06 22:57

No need to go for WindowPrc as this is an additional work. Becase its already available as part of the framework class library. Given below is a working sample on VS2005. Copy this code in to the .h file of your Form.

virtual void WndProc( Message% m ) override<br />
{        <br />
 // Listen for operating system messages.<br />
 switch ( m.Msg )<br />
 {<br />
    case WM_ACTIVATEAPP:                           <br />
       this->Invalidate();<br />
       break;<br />
 }<br />
 Form::WndProc( m );<br />
}

you have to include windows.h for WM_ACTIVATEAPP to work.

cheers..Milton Kb.

mmhu11-Aug-06 4:24

11-Aug-06 4:24

m.LParam is a System::IntPtr, I have problem to convert m.LParam to a
PDEV_BROADCAST_HDRstructure.
I tried:
PDEV_BROADCAST_HDR lpdb = (PDEV_BROADCAST_HDR)(m->LParam);
compiler gives error:
error C2440: 'type cast' : cannot convert from 'System::IntPtr' to 'PDEV_BROADCAST_HDR'No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called

I tried:

lpdb = (PDEV_BROADCAST_HDR)(m->GetLParam(__typeof(PDEV_BROADCAST_HDR)));
compiler generates following error:
error C3181: 'PDEV_BROADCAST_HDR' : invalid operand for __typeof, expected a fully defined managed type

What is the correct way?

Milton Karimbekallil13-Aug-06 20:47

13-Aug-06 20:47

try PDEV_BROADCAST_HDR lpdb = (PDEV_BROADCAST_HDR)(m.LParam.ToPointer());

cheers..Milton KB.

mmhu14-Aug-06 2:17

14-Aug-06 2:17

Thanks a lot Milton,

It works.

Vicky

Milton Karimbekallil15-Aug-06 18:00

15-Aug-06 18:00

Guess u forgot the fact that C++/CLI ^ pointer operator and the tracking reference operator % are not equivalent to its native like counterpart operators * pointer and the & reference. Actually ^ is a handle to its managed heap object and its not a pointer to that. But the handle can provide us with the underlying pointer just like we did.

cheers..Milton KB

mmhu17-Aug-06 11:05