Serial IO in VisualStudio 2011 / C++

I needed to hack together a quick windows application to read data over a serial port and write it to a file. Unfortunately I think VisualStudio is probably still the best way of writing Win32 GUI apps. However I’ve not really used VisualStudio since the VisualStudio.net beta, and most of the stuff I did before that was on VisualStudio 6.

Man Microsoft have really murdered C++… are these proprietary garbage collection extensions all over the place? I couldn’t see a way of writing a pure C++, unmanaged GUI app in VS 2011…

Anyway, to get Serial IO working in a GUI application I needed to add the following methods, these were all added to the Form itself, like I say this was a quick hack:

public:
	// members
	String^ comport;
	String^ dump_filepath;
	String^ current_filename;
	SerialPort^ serialn;

	// initalise serial port
	void init_acquire() {
		int baudRate=9600;

		serialn = gcnew SerialPort(comport, baudRate);

		serialn->ReadTimeout = 50;

		serialn->Open();
	}

	// Read from serial port
	String^ acquire() {;
		String^ s;
		try {
			s = serialn->ReadLine();
		}
		catch (TimeoutException ^) { }
		
		return s;
	}

	// Button handler, starts thread
	private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {

		dumped_lines      = 0;
		dumped_file_count = 0;
		dump_filepath = this->drop_location_textbox->Text;
		current_filename = dump_filepath + dumped_file_count + ".txt";

		comport = comport_textbox->Text;

	    ThreadStart ^myThreadDelegate = gcnew ThreadStart(this, &Form1::repeat);
		trd = gcnew Thread(myThreadDelegate);
		trd->IsBackground = true;
		trd->Start();
		dumped_lines = 0;
	}

	// Thread code
	delegate void DelegateThreadTask();
	private: void ThreadTask() {

		// This weirdness is required because setting the TextBox text is not thread safe.
		if (data_textbox->InvokeRequired == false) {
			String ^data = acquire();
			this->data_textbox->Text = this->data_textbox->Text + data;
			//current_filename

			StreamWriter^ sw = gcnew StreamWriter(current_filename,true);

			sw->WriteLine(data);

			sw->Close();

		} else {
			DelegateThreadTask ^myThreadDelegate = gcnew DelegateThreadTask(this,&Form1::ThreadTask);
			this->Invoke(myThreadDelegate);			
		}
	}

	// Thread loop (reads from serial, dumps to file/textbox.
	private: void repeat() {
		init_acquire();
		while(true) {
			ThreadTask();
			Thread::Sleep(100);
		}
	}

You’ll also need to add the following headers:

	using namespace System::IO::Ports;
	using namespace System::Threading;
	using namespace System::IO;

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