RS232 port.close崩溃程序 [英] RS232 port.close crashes program
问题描述
早上好，
我有一个程序通过RS232从秤上读取重量.规模一旦稳定，就只会不断地抽出数据.因此，在加载表单时，我禁用了RS232事件处理程序.扫描与称重相关的序列号后，我启用rs232接收事件并将值读取到文本框中.读取完成后，我再次禁用了接收事件.这一切都完美地工作.
当我尝试关闭端口时，问题就来了.
Good day,
I have a program reading a weight from a scale through RS232. The scale, once stable, just keeps pumping data out. So when the form loads I disable the RS232 event handler. After the serial number related to the weighing is scanned I enable the rs232 receive event and read the values into a textbox. After the read is completed I disable the receive event again. This all works perfectly.
The problem comes when I try to close the Port.
Private Sub frmBoxCheck_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Try
''AddHandler MyPort.DataReceived, AddressOf MyPort_DataReceived
''MyPort.ReadBufferSize = 0
''MyPort.PortName = "COM1"
RemoveHandler MyPort.DataReceived, AddressOf MyPort_DataReceived
MyPort.DiscardInBuffer()
If MyPort.IsOpen = True Then MyPort.Close()
If dat.IsTableLoaded("AccessorySetup") = True Then dat.DS.Tables.Remove("AccessorySetup")
If dat.IsTableLoaded("SCALES") = True Then dat.DS.Tables.Remove("SCALES")
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
If MyPort.IsOpen = True Then MyPort.Close()
当程序命中myport.close时，整个应用程序将挂起，并且使其再次运行的唯一方法是重新引导计算机.您无法停止该过程.请参见下面的代码，欢迎提出任何想法.谢谢
If MyPort.IsOpen = True Then MyPort.Close()
When the program hits myport.close the whole app hangs and the only way to make it work again is to reboot the machine. You cannot stop the process. Please see code below any ideas are welcome. thanks
<pre lang="msil">Private Sub frmBoxCheck_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
''Disable the rs232 read event
RemoveHandler MyPort.DataReceived, AddressOf MyPort_DataReceived
''Setup Rs232 port
Rs232_Setup()
End Sub
Sub Rs232_Setup()
Try
If dat.ScaleLoad_Table("SELECT * FROM [ACCESSORY].[dbo].[Setup]", "AccessorySetup") = True Then
Dim intScaleID As Integer = 0
intScaleID = dat.DS.Tables("AccessorySetup").Rows(2).Item("SetupValue")
If dat.ScaleLoad_Table("SELECT * From [ACCESSORY].[dbo].[Scales] WHERE ScaleID=''" & intScaleID & "''", "SCALES") = True Then
Dim dtScale = dat.DS.Tables("SCALES")
If dtScale.Rows.Count = 1 Then
MyPort.PortName = dtScale.Rows(0).Item("LastComPort").ToString
Dim strRS232Full As String
Dim strRS232Setup(20) As String
strRS232Full = dtScale.Rows(0).Item("RS232_Setup").ToString
strRS232Setup = strRS232Full.Split(",")
MyPort.PortName = dtScale.Rows(0).Item("LastComPort").ToString
MyPort.BaudRate = strRS232Setup(0)
MyPort.DataBits = strRS232Setup(1)
''Stop bit
Select Case strRS232Setup(2)
Case "0"
MyPort.StopBits = Ports.StopBits.None
Case "1"
MyPort.StopBits = Ports.StopBits.One
Case "1.5"
MyPort.StopBits = Ports.StopBits.OnePointFive
Case "2"
MyPort.StopBits = Ports.StopBits.Two
End Select
''Parity
Select Case strRS232Setup(3)
Case "None"
MyPort.Parity = Ports.Parity.None
Case "Even"
MyPort.Parity = Ports.Parity.Even
Case "Odd"
MyPort.Parity = Ports.Parity.Odd
Case "Mark"
MyPort.Parity = Ports.Parity.Mark
Case "Space"
MyPort.Parity = Ports.Parity.Space
End Select
MyPort.ReadTimeout = 1000
MyPort.Handshake = Ports.Handshake.None
MyPort.Open()
Else
MessageBox.Show("Scale not found or too many values returned.")
End If
Else
MessageBox.Show("Cannot Load Scale table.")
End If
Else
MessageBox.Show("Cannot Load Accessory setup table.")
End If
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Sub MyPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles MyPort.DataReceived
Try
''Pause for 100ms
Threading.Thread.Sleep(100)
''Add values read to a string builder
myStringBuilder.Append(MyPort.ReadLine)
''Pass the string builder to the update text box delegate
Me.Invoke(New EventHandler(AddressOf UpdateTextBox))
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Public Sub UpdateTextBox()
Try
Dim arryCnt As Integer = 11
''Write the entire mess into a texbox and trim off the edges
txtRead.AppendText(";" & myStringBuilder.ToString)
myStringBuilder.Remove(0, myStringBuilder.Length)
''Release port
''remove receive event handler
RemoveHandler MyPort.DataReceived, AddressOf MyPort_DataReceived
''Clear the input buffer in the driver
'' MyPort.DiscardInBuffer()
''Close the port
''If MyPort.IsOpen = True Then MyPort.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
推荐答案
鉴于这只是RS232数据，因此数据速率将非常低.我很想保持接收状态连续，并更新我的课程中的当前权重"值(可能是静态的，因为每个端口只能有一个).然后，您的问题应该消失了:接收到数据后，处理程序仍然存在.应该花很长时间检查...
Given that this is only RS232 data, the data rate is going to be pretty low. I would be very tempted to keep the receive enabled continuously, and update a "current weight" value (probably static since there can be only one per port) in my class. Then your problem should disappear: then handler still exists when data is received. It shouldn''t take long to check...
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