Question

I am developing a Windows forms application which connects to a piece of hardware, acquires a lot of data (~1 GSample/sec), processes it, and spits it out to the screen upon a button click. I am now trying to automate the process in a loop that can be started/stopped at any time so I can monitor it whilst tweaking the input to the acquisition hardware. I thinks it’s clear that I need to do this on a separate thread, but I’m having a heck of a time trying to do this in c++/cli – I have found a number of good examples using MFC, which is not supported by Express.

Specifically: My task is to press a button which is handled in Form1.h, to call a function in my main file Acquisition.cpp which contains the following code (currently an infinite loop)

void Form1::realTimeUpdate()  
{  
    // live is a boolean variable set by a button on the form
    while(live)  
    {  
        displayVariance(getVar(getQuadratures(100),nbrSamples));  
    }  
}  

I wish to execute this code in a separate thread so that the main program can listen for the user request to stop the operation. Without threading, I currently have to forcefully quit the program (or set it to run a fixed number of times) to stop it.

Is there any suggestions how I might go about running this code on a separate thread?

I’ve (unsuccessfully) tried a few things already:

1. Modifying the example given in This Microsoft Example. Problem: requires /clr:oldSyntax option which is incompatible with the other 1300 lines of code in the program.

2. Trying to do what I’d do in Java (Declare a global thread and start/stop it from any point in the code. Problem: Compiler won’t let me declare a global System::Threading.Thread

3. this beautiful example. Problem: Requires MFC.

Any suggestions would be greatly appreciated!

Answer 1

You can use a BackgroundWorker or a Thread to handle this. You’ll need to make sure that the portion of your work that updates the UI is marshaled back to the UI thread, however.

Here is a tutorial on threading in C++/CLI.