关于vb点虐 com事件的信息
vb点虐 怎么用事件触发的方式读取串口数据
首先:
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textbox里没有显示,是因为SerialPort1和TextBox2不是同一线程创建的,需要跨线程操作。需要用到委托,这样才能显示出来。
其次:
我觉得用串口的接收数据事件更好一些。
下面代码供参考:
'----------------------
'串口接收数据事件,其实比用定时器更好,
'触发事件的条件可以自己在form_load中设置ReceivedBytesThreshold属性数值,默认为ReceivedBytesThreshold=1
Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
Dim strRecvData As String = ""
strRecvData = SerialPort1.ReadExisting
Call disPlayComData(strRecvData)
End Sub
Delegate Sub callback(ByVal strT As String) '定义委托
Sub showString(ByVal comdata As String) '显示结果
Me.TextBox1.Text = "结果:" comdata
End Sub
Sub disPlayComData(ByVal strTmp As String) '判定是否为跨线程
If Me.TextBox1.InvokeRequired Then
Dim d As New callback(AddressOf showString)
Me.Invoke(d, New Object() {strTmp})
Else
Me.TextBox1.Text = strTmp
End If
End Sub
vb点虐 程序如何实现向电脑的Com口发送一段字符串信息,之后再接收显示发送的字符串信息?
'vb点虐 的串口接收数据要用到委托
Delegate Sub SetTextCallback(ByVal InputString As String) '声明一个委派类,并声明符合函数参数有一个,而其型态是字符串
Private Sub ShowString(ByVal comData As String)
txt_Re.Text = comData '将收到的数据入接收文字框中--- txt_Re.Text 是接收用的文本框
txt_Re.SelectionStart = txt_Re.Text.Length
txt_Re.ScrollToCaret()
End Sub
Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived‘自动接收事件
Dim inData As String = SerialPort1.ReadExisting
Dim d As New SetTextCallback(AddressOf ShowString)
Invoke(d, inData)
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click '发送指令
SerialPort1.Write("123")
End Sub
vb点虐 动态菜单,如何添加事件?
动态生成的控件:
Private Sub UserControl1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim myPicture = New System.Windows.Forms.PictureBox()
Me.Panel3.Controls.Add(myPicture)
myPicture.Size = New System.Drawing.Size(115, 160)
myPicture.TabStop = False
myPicture.Name = "p"
myPicture.Cursor = Cursors.Hand
AddHandler myPicture.Click, AddressOf mypic_Click '添加事件
End Sub
处理事件的过程:
Private Sub mypic_Click() 'ByVal id As String
Dim bookInfo As New BookInfo
bookInfo.Show()
Me.Parent.Enabled = False
VB点虐 中DataGridViewComboBoxColumn事件
你可以在rowbound的时候把isGetCom代码加的这里vb的话肯能是要写在itembound事件里。你也可以先把查出的数据放对dataview里然后点排序的时候对dataview进行排序,最后在重新绑定gridview"怎么在我下拉点先值后(下拉框收缩后)不管焦点有没有移出这个单元格都会发生事件“IsGetCom()”事件"你要实现这个必须把下拉框的AutoPostBcak属性设为ture
本文标题:关于vb点虐 com事件的信息
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