Obvious Oversite?
This problem has to do with updating a control/dataset based on the DataRecevied event of the serial port. Now I know you are thinking cross threading (which it might be) but let me explain.
I have a dataset in the main UI form that is databound to a number of controls. When I change the values of the dataset the bound controls update. This is fine, but when I update the values of the dataset via the DataReceived event the values DON'T update? To illlustrate the problem simply I have stripped down the code to it's most basic form. I hope someone can shed some light on the problem.
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
// create a dataset and populate it with data
UnitDataSet uds = new UnitDataSet();
uds.DIns.ReadXml("Data.xml");
// create a new comms instance and pass a ref to the dataset
_comms = new Comms(uds);
// create a label to bind too
Label lblInputState = new Label();
panel1.Controls.Add(lblInputState);
// databind the control to the state column
lblInputState.DataBindings.Add("Text", uds.Tables["DIns"], "state");
}
// used to test if the binding works and value changes as expected
public void button1_Click(object sender, EventArgs e)
{
_comms.ChangeValue();
}
}
================================================== ==========
class Comms
{
SerialPort _sp;
UnitDataSet _uds;
public Comms(UnitDataSet uds)
{
_uds = uds;
_sp = new SerialPort("COM7", 9600, Parity.None, 8, StopBits.One);
_sp.DataReceived += new SerialDataReceivedEventHandler(_sp_DataReceived);
_sp.Open();
}
private void _sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
// run this method when the event fires
ChangeValue();
}
// if i call this from the main form button (see above ) the value changes but if it's called
// by the above DataReceived event the value doesn't change!?!
public void ChangeValue()
{
// simple toggle to change the value
bool tmp = (bool)_uds.Tables["DIns"].Rows[0]["state"];
_uds.Tables["DIns"].Rows[0]["state"] = !tmp;
}
}
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