Instead of using a complicated Sendmessge between processes, there is another convenient way to communicate between processes. Pipe!

There is a good tutorial and implementation demo with C#. link

I just used the server client in my program. But for the client, I used a simple C++ implementation.

HANDLE h=NULL;
void send_message(char *msg)
{
	if (!h)
		{
			h=CreateFile(L"\\\\.\\pipe\\MyNamedPip",
			      GENERIC_READ | GENERIC_WRITE,
                  0,
                  NULL,
                  OPEN_EXISTING,
                  FILE_FLAG_OVERLAPPED,
				  NULL);
		}

	DWORD BytesWritten;
	WriteFile(h,msg,strlen(msg),&BytesWritten,NULL);
	FlushFileBuffers(h);
}

Tags: C#, VC++.net, Win32

上了贼船, 只能当贼.
Following the weird syntax of VC++.net, here is how to declare an array of a dotnet object references.

static array<System::Threading::Mutex^>^ trackers_mut = gcnew array<System::Threading::Mutex^>(10);

or

array <String^>^ filenames={"aa", "bb"};

有点抓狂. 但的确是这么写的. C及其衍生物总是那么变化无穷.

Tags: VC++.net

In Old times, I still remember how cool it is to add a media player in my Delphi Form. Now I need to do the same to VC++.net, so I searched and got these links. Although they are not VC++.net solution, they still help a lot.

With some codec (here), this way can enable your application play video of most popular formats. So give up the other version of using Direct X to play only AVI format video in dotnet application.

Here are the links (still updating)

How to add Windows Media Player Control to Design ToolBox

How to use Windows Media Player in code (C# Version)

Tags: dotnet, VC++.net, Visual Studio

It has been quite a while since last time I post a howto of configuring OpenCV in Visual Studio. The post got a lot of attention and comments. As the the configuring has become simpler, the post becomes a bit bulky and out-of-date. So right now I am considering to rewrite the howto with a much simpler version.

C:\Program Files\OpenCV\cv\include
C:\Program Files\OpenCV\otherlibs\highgui
C:\Program Files\OpenCV\cxcore\include
C:\Program Files\OpenCV\otherlibs\cvcam\include

C:\Program Files\OpenCV\lib

cv.lib highgui.lib cvaux.lib cxcore.lib

Tested on OpenCV 1.0 with Visual Studio 2008

Links
Original blogspot link1 link2.
Li Hao’s post.

Tags: OpenCV, Visual Studio

Comments(2)

Continuous updating…
Current testing version: OpenCV 1.0 (I do not recommend the latest 1.1pre1. I got strange error using it in VC.net). VC++.net 2008.

Set up a project in Visual Studio

Convert IplImage to VC++.net Bitmap

System::Drawing::Bitmap ^disp = gcnew System::Drawing::Bitmap(img->width, img->height, img->widthStep, PixelFormat::Format24bppRgb, System::IntPtr::IntPtr( img->imageData) );

Tags: OpenCV, VC++.net

File drop is an easy-to-use feature for users, as users can directly drag-and-drop a file from file browser onto your application. People may think it is difficult to implement. But actually, it is rather easy. Here is a fast way to start.

The main idea is to handle these two events, QDropEvent and QDragEnterEvent. The following shows how to handle them in your app.

First, add the following code to the class declaration in a header file,

protected:
    void dropEvent(QDropEvent *event);
    void dragEnterEvent(QDragEnterEvent *event);

Then add the implementation to the cpp file,

void CLASS::dragEnterEvent(QDragEnterEvent *event)
{
  if (event && event->mimeData()) {
    const QMimeData* md = event->mimeData();
    if (md->hasUrls())
        event->acceptProposedAction();
  }
}

and

void CLASS::dropEvent(QDropEvent *event)
{
    const QMimeData *data = event->mimeData();
    if(data->hasUrls())
      foreach(QUrl url, data->urls()) {
        QFileInfo info(url.toLocalFile());
            if(info.exists() && info.isFile())
          ///// do something with url.tolocalFile()
      }
}

One more thing, add the following code in the constructor of the class to enable the widget to accept the events.

setAcceptDrops(true);

That’s all!

Tags: QT

Nautilus, Explorer and Finder are GUI file browsers of Ubuntu, Windows, and Mac OS respectively. No matter under which system, it would be extremely convenient if users can open a terminal with path being the same as location of the file browsers or vice versa. Here I show the ways of doing such under each system.

Ubuntu
Open terminal in Nautilus:
just install nautilus-open-terminal with your Synaptic Package Manager, then you can find a “open in terminal” item in your context menu of your Nautilus.

Open Nautilus in terminal

nautilus . 

Windows
Open cmd line in Explorer
install cmdhere tool in the collections of powertoys provided by Microsoft

Open Explorer in terminal

start .

Mac OS
Open terminal in Finder
Download a simple cdto … app here and drag it onto your Finder toolbar. Clicking it will open a terminal with the current path in Finder.

Open Finder in terminal

open .

Tags: MacOS, ubuntu, Windows

If you have a server supporting ssh, you can easily create a socks proxy with ssh under linux, using the following commnd

$ssh -D portnumber username@ip-address-of-ssh-server

Then you got a socks proxy, localhost:portnumber. Just enjoy it in your browser or somewhere else.

Keep the terminal alive until u don’t need the proxy anymore.

Tags: ubuntu

Include

#include <QTextStream>
#include <stdio.h>

Create these instances globally

QTextStream cin(stdin, QIODevice::ReadOnly);
QTextStream cout(stdout, QIODevice::WriteOnly);
QTextStream cerr(stderr, QIODevice::WriteOnly);

Then you can use

cout<<QString("bla bla")<<endl

as you wish.

refer: http://lists.trolltech.com/qt4-preview-feedback/2005-03/thread00012-0.html

Tags: QT

Install OpenCV with Synaptic Package Manager
Add one line in QT project file (*.pro)

LIBS += -L/usr/local/lib -lcxcore -lcv -lhighgui -lcvaux

Then, include OpenCV header file in your source code.
Do whatever you like in your source file.
Compile.

Note: This post is incomplete so far and subject to change.

Tags: OpenCV, QT, ubuntu