vb.net串口源码 vbnet串口控件

VB.net串口通讯接收数据写法

Do

   Application.DoEvents()

Loop Until MSComm1.InBufferCount = 13

Dim a As String = MSComm1.Input

Label1.Caption = a.Substring(1, 9)

Label2.Caption = a.Substring(10, 3)

相关问答

Q1: 怎样在vb中自动检测到可用串口号的具体程序代码

vb.net的话

For

Each

sp

As

String

In

My.Computer.Ports.SerialPortNames

cbxport.Items.Add(sp)

Next

vb6.0的话要调用API查看串口相关信息存在的注册表。

HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM

通过读注册表的方法获得串口数量，当然也可以获得串口号了。

Option

Explicit

Private

Declare

Function

RegOpenKey

Lib

"advapi32.dll

"

Alias

"RegOpenKeyA

"

(ByVal

hKey

As

Long,

ByVal

lpSubKey

As

String,

phkResult

As

Long)

As

Long

Private

Declare

Function

RegQueryInfoKey

Lib

"advapi32.dll

"

Alias

"RegQueryInfoKeyA

"

(ByVal

hKey

As

Long,

ByVal

lpClass

As

String,

lpcbClass

As

Long,

ByVal

lpReserved

As

Long,

lpcSubKeys

As

Long,

lpcbMaxSubKeyLen

As

Long,

lpcbMaxClassLen

As

Long,

lpcValues

As

Long,

lpcbMaxValueNameLen

As

Long,

lpcbMaxValueLen

As

Long,

lpcbSecurityDescriptor

As

Long,

lpftLastWriteTime

As

Long)

As

Long

Private

Const

HKEY_LOCAL_MACHINE

=

H80000002

'

获得当前系统的

COM

口的数量

Function

GetCOMCount()

As

Integer

Dim

ret

As

Long,

cntCOM

As

Long

RegOpenKey

HKEY_LOCAL_MACHINE,

"HARDWARE\DEVICEMAP\SERIALCOMM

",

ret

RegQueryInfoKey

ret,

"

",

0,

0,

0,

0,

0,

cntCOM,

0,

0,

0,

GetCOMCount

=

cntCOM

End

Function

Private

Sub

Command1_Click()

MsgBox

"您的机器有

"

GetCOMCount

"

个串口。

",

vbOKOnly,

"串口数量

"

End

Sub

Q2: 能给我发个VB与三菱PLC通讯的源代码实例吗，非常感谢啊

得说明是什么型号的PLC啊vb.net串口源码，串口还是网口vb.net串口源码，VB6还是VB.NET？

算vb.net串口源码了vb.net串口源码，写段代码，VB.NET与Q系列以太网通讯的：

Imports System.Net

Imports System.Runtime.InteropServices

Public Class Form1

    Dim Handle1 As Int32

    Dim EntLink1 As Boolean

    Dim ScanCount1 As Long

    Dim PLC As New EntQsPlc_Asc.PlcClient'EntQsPlc_ASC.DLL是Q系列以太网通讯组件

    Public Declare Function timeGetTime Lib "winmm.dll" () As UInt32

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Me.CenterToScreen()

        cmbReadMry.Items.Clear()

        cmbReadMry.Items.Add("X")

        cmbReadMry.Items.Add("Y")

        cmbReadMry.Items.Add("M")

        cmbReadMry.Items.Add("D")

        cmbReadMry.Items.Add("R")

        cmbReadMry.Items.Add("Z")

        '

        cmbWriteMry.Items.Clear()

        cmbWriteMry.Items.Add("X")

        cmbWriteMry.Items.Add("Y")

        cmbWriteMry.Items.Add("M")

        cmbWriteMry.Items.Add("D")

        cmbWriteMry.Items.Add("R")

        cmbWriteMry.Items.Add("Z")

        '

        cmbBitMry.Items.Clear()

        cmbBitMry.Items.Add("X")

        cmbBitMry.Items.Add("Y")

        cmbBitMry.Items.Add("M")

        '

        cmbReadType.Items.Clear()

        cmbReadType.Items.Add("INT16")

        cmbReadType.Items.Add("UINT16")

        cmbReadType.Items.Add("DINT32")

        cmbReadType.Items.Add("HEX32")

        cmbReadType.Items.Add("REAL32")

        cmbReadType.Items.Add("BIN16")

        '

        cmbWriteType.Items.Clear()

        cmbWriteType.Items.Add("INT16")

        cmbWriteType.Items.Add("UINT16")

        cmbWriteType.Items.Add("DINT32")

        cmbWriteType.Items.Add("HEX32")

        cmbWriteType.Items.Add("REAL32")

        cmbWriteType.Items.Add("BIN16")

        cmbReadMry.SelectedIndex = 3

        cmbWriteMry.SelectedIndex = 3

        cmbBitMry.SelectedIndex = 2

        cmbReadType.SelectedIndex = 0

        cmbWriteType.SelectedIndex = 0

        lstRead.Items.Clear()

        txtWrite.Text = ""

        '

        cmbCmdType.SelectedIndex = 0

    End Sub

    Private Sub butLink_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butLink.Click

        Dim re As Short

        Dim restr As String = ""

        re = PLC.EntLink(Trim(txtLocalIP.Text), Val(txtLocalPort.Text), Trim(txtRemoteIP.Text), Val(txtRemotePort.Text), "DEMO", Handle1, 1000, CBool(cmbCmdType.SelectedIndex))

        txtReLink.Text = re.ToString

        If re = 0 Then

            EntLink1 = True

            MsgBox("PLC联接成功! ")

        Else

            EntLink1 = False

            MsgBox("PLC联接失败: "  restr)

        End If

    End Sub           

    Private Sub butClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butClose.Click

        Dim re As Short

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            Exit Sub

        End If

        re = PLC.DeLink(Handle1)

        txtReClose.Text = re.ToString

    End Sub

    Private Sub butRead_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butRead.Click

        Dim re As Short

        Dim i As Short

        Dim RD() As Object

        ReDim RD(Val(txtReadCnt.Text - 1))

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            ' Exit Sub

        End If

        Dim mry As EntQsPlc_Asc.PlcClient.PlcMemory = cmbReadMry.SelectedIndex + 1

        Dim typ As EntQsPlc_Asc.PlcClient.DataType = cmbReadType.SelectedIndex + 1

        re = PLC.CmdRead(Handle1, mry, typ, CInt(txtReadAdd.Text), CUShort(txtReadCnt.Text), RD)

        txtReRead.Text = re.ToString

        lstRead.Items.Clear()

        For i = 0 To UBound(RD) Step 1

            If Not IsNothing(RD(i)) Then lstRead.Items.Add(RD(i))

        Next i

        If re  0 Then

            Timer1.Enabled = False

            butScan.Text = "Cycle R/W"

        End If

    End Sub

    Private Sub butWrite_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butWrite.Click

        Dim re As Short

        Dim i As Short

        Dim temp() As String

        Dim WD() As Object

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            Exit Sub

        End If

        ReDim WD(Val(txtWriteCnt.Text) - 1)

        temp = Split(txtWrite.Text, vbCrLf)

        For i = 0 To UBound(WD) Step 1

            If i  UBound(temp) Then

                WD(i) = 0

            Else

                WD(i) = Trim(temp(i))

            End If

        Next i

        Dim mry As EntQsPlc_Asc.PlcClient.PlcMemory = cmbWriteMry.SelectedIndex + 1

        Dim typ As EntQsPlc_Asc.PlcClient.DataType = cmbWriteType.SelectedIndex + 1

        re = PLC.CmdWrite(Handle1, mry, typ, CInt(txtWriteAdd.Text), CUShort(txtWriteCnt.Text), WD)

        txtReWrite.Text = re.ToString

        If re  0 Then

            Timer1.Enabled = False

            butScan.Text = "Cycle R/W"

        End If

    End Sub

    

    

    Private Sub butScan_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butScan.Click

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            Exit Sub

        End If

        Timer1.Enabled = Not Timer1.Enabled

        If Timer1.Enabled Then

            ScanCount1 = 0

            butScan.Text = "Stop R/W"

        Else

            butScan.Text = "Cycle R/W"

        End If

    End Sub

    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick

        Timer1.Enabled = False

        Dim tim As Integer = timeGetTime

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            Exit Sub

        End If

        '

        Call butRead_Click(Nothing, Nothing)

        Call butWrite_Click(Nothing, Nothing)

        '

        If (Val(txtReRead.Text)  0) Or (Val(txtReWrite.Text)  0) Then

            butScan.Text = "Cycle R/W"

            Exit Sub

        Else

            ScanCount1 += 1

            txtScanCnt.Text = ScanCount1

            txtScanPrd.Text = (timeGetTime - tim)  "ms"

        End If

        Timer1.Enabled = True

    End Sub

    Private Sub butBitTest_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butBitTest.Click

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            Exit Sub

        End If

        Dim rd As Boolean

        Dim re As Short

        Dim mry As EntQsPlc_Asc.PlcClient.PlcMemory = cmbBitMry.SelectedIndex + 1

        re = PLC.Bit_Test(Handle1, mry, CUShort(txtBitAdd.Text), rd)

        txtBitTest.Text = rd

        txtReBit.Text = re

    End Sub

    Private Sub butBitSet_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butBitSet.Click

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            Exit Sub

        End If

        Dim re As Short

        re = PLC.Bit_Set(Handle1, cmbBitMry.SelectedIndex + 1, Val(txtBitAdd.Text))

        txtReBit.Text = re

    End Sub

    Private Sub butBitRst_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butBitRst.Click

        If Not EntLink1 Then

            MsgBox("还未与PLC建立联接！")

            Exit Sub

        End If

        Dim re As Short

        re = PLC.Bit_Reset(Handle1, cmbBitMry.SelectedIndex + 1, Val(txtBitAdd.Text))

        txtReBit.Text = re

    End Sub

End Class

Q3: 如何用vb.net获得网页的源代码

Dim url As String=" 网址"

Dim httpReq As System.Net.HttpWebRequest

Dim httpResp As System.Net.HttpWebResponse

Dim httpURL As New System.Uri(url)

httpReq = CType(WebRequest.Create(httpURL), HttpWebRequest)

httpReq.Method = "GET"

httpResp = CType(httpReq.GetResponse(), HttpWebResponse)

httpReq.KeepAlive = False ' 获取或设置一个值，该值指示是否与

Internet资源建立持久连接。

Dim reader As StreamReader = _

New StreamReader(httpResp.GetResponseStream,

System.Text.Encoding.GetEncoding(-0))

Dim respHTML As String = reader.ReadToEnd() 'respHTML就是网页源代码

Q4: VB.NET中如何处理串口通信接收的数据？

你可以预先约定一个截止附，读取的字节统统放到缓存区里，直到读到截止附再处理、显示。

Q5: vb.net2010十六进制读取串口的问题

不是很明白你的题意

strHex = strHex + [String].Format("{0:X2} "

这里的意思是把每个字节数据转换成了十六进制，每个字节占两个字符

如果你串口收到的4个字节数据：43,27,56,200

那么你的结果是：2B1B38C8

即receivebytes.Text="2B1B38C8"

不足两位的补0

如果你串口收到的4个字节数据：3,27,56,200

那么你的结果是：031B38C8

即receivebytes.Text="031B38C8"

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