Yesterday I wanted to try Honeywell's sweep gun, the scanner has two modes, keyboard mode and serial port mode,
1, keyboard mode directly inserted on the line, just like a keyboard does not need any driver, swept out of the data directly to the input focus of the PC. Just like a keyboard, you can only enter characters.
2, and the serial port mode, is installed after the driver, can be virtual into a COM port,
If we use a scanner to input data to the application is certainly not possible, because the program needs to be able to run in the background can also use the scanner as data input. This requires the use of serial port mode.
Today, when I write the program, the problem is how can not trigger, datareceived events, finally found the problem, a few points
1, the serial port must be new instance, must and can correctly obtain the hardware serial port name.
2, Sp. Receivedbytesthreshold = 1; This is the default value of 1, which is to trigger the event with one byte of data.
3, Sp. rtsenable = True;sp. Dtrenable = true; These two properties must be set correctly, ha
That's why I haven't been able to trigger events correctly for a 3rd reason. Remember to add the event binding code AH.
public partial class Form1:form
{
SerialPort sp;
BOOL bisreading = false;
Dynamic d = new dynamic ();
Public Form1 ()
{
InitializeComponent ();
}
private void Button1_Click (object sender, EventArgs e)
{
BOOL B = false;
Try
{
SP = new SerialPort ();
Sp. BaudRate = 115200;
Sp. DataBits = 8;
Sp. Parity = Parity.none;
Sp. StopBits = Stopbits.one;
Sp. PortName = System.IO.Ports.SerialPort.GetPortNames () [0];
Sp. Rtsenable = true;
Sp. Dtrenable = true;
Sp. ReadTimeout = 3000;
Sp. Receivedbytesthreshold = 1;
Sp. DataReceived + = new System.IO.Ports.SerialDataReceivedEventHandler (this.sp_datareceived_1);
Sp. DataReceived + = sp_datareceived;
Sp. DataReceived-= sp_datareceived;
Sp. Open ();
}
catch (Exception Xe)
{
B = true;
MessageBox.Show ("Exception:" + XE. Message);
}
finally {
if (sp! = null && b = = true)
{
if (sp. IsOpen)
{
Sp. Close ();
} else
{
SP = null;
}
}
b = false;
}
}
private void Form1_formclosing (object sender, FormClosingEventArgs e)
{
Sp. Discardinbuffer ();
if (sp! = null)
{
Sp. Close ();
Sp. Dispose ();
}
}
private void Sp_datareceived_1 (object sender, Serialdatareceivedeventargs e)
{
if (bisreading = = True)
Return
Bisreading = true;
Try
{
StringBuilder currentline = new StringBuilder ();
Loop receive data
while (sp. Bytestoread > 0)
{
char ch = (char) sp. ReadByte ();
CurrentLine. Append (CH);
}
To handle the data received here.
MessageBox.Show ("Data is:" + currentline. ToString ());
GlobalPublic.BasePublic.ShowMessage ("Data is:" + currentline. ToString (), (basefrm as Baseform.frmbasedoc). Mtc_oglobal);
Invokedelegate del = new Invokedelegate (SetItem);
This. BeginInvoke (Del, CurrentLine. ToString ());
SetItem (CurrentLine. ToString ());
CurrentLine = new StringBuilder ();
}
catch (Exception ex)
{
MessageBox.Show ("Exception:" + ex.) Message);
}
Finally
{
Bisreading = false;
}
}
}
}
C # SerialPort's DataReceived event could not be triggered, using Honeywell's scanning gun and the corresponding USB to serial port driver.