从combobox
中选择项目后,如何在自动输入textbox
后自动输入一个数字到。我所知道要做的就是从combobox
到textbox
的数据。但是我想要做的是在选择项目后将数据添加到textbox
。从组合框中选择项目时向文本框中添加新数据
这是我的代码:
Imports System.Data.OleDb
Imports System.Data
Public Class voting1
Dim con As New OleDbConnection
Dim Com As New OleDbCommand
Dim ComInsert As New OleDbCommand
Dim ComUpdate As New OleDbCommand
Dim ComDelete As New OleDbCommand
Dim aAdapter As New OleDbDataAdapter
Dim Dset As New DataSet
Private Sub voting1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim ConProvider As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=J:\EvS\EVS.accdb"
Try
Try
con.ConnectionString = ConProvider
If Not con.State = ConnectionState.Open Then
con.Open()
End If
Catch ex As Exception
MsgBox("No Connection Established")
End Try
Me.fill()
user.Visible = False
user.Text = Form1.usertxt.Text
Catch ex As Exception
End Try
End Sub
Private Sub fill()
With aAdapter
.SelectCommand = New OleDb.OleDbCommand()
.SelectCommand.CommandText = "select * from candidate"
.SelectCommand.Connection = con
End With
Dim dataRead As OleDb.OleDbDataReader
dataRead = aAdapter.SelectCommand.ExecuteReader()
While (dataRead.Read())
presbox.Items.Add(dataRead("President"))
vpbox.Items.Add(dataRead("VicePresident"))
secbox.Items.Add(dataRead("Secretary"))
treasbox.Items.Add(dataRead("Treasurer"))
End While
aAdapter.Dispose()
End Sub
Public Sub Initialize()
Try
If Not con.State = ConnectionState.Open Then
con.Open()
End If
Catch ex As System.Exception
MsgBox(ex.Message, MsgBoxStyle.Information, "ERROR CONNECTION")
End Try
End Sub
Private Sub bo()
Dim con1 As New OleDbConnection
Dim cmd As New OleDbCommand
con1.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=J:\EvS\EVS.accdb"
cmd.Connection = con1
con1.Open()
Dim num As Integer
cmd.CommandText = "SELECT pres1 FROM vote1"
If IsDBNull(cmd.ExecuteScalar) Then
num = 1
samp.Text = num
Else
num = 1
samp.Text = num
End If
cmd.Dispose()
con1.Close()
con1.Dispose()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Try
Call Initialize()
If presbox.Text = "" Or vpbox.Text = "" Or secbox.Text = "" Or treasbox.Text = "" Then
MsgBox("All Fields are required, Check the fields", MsgBoxStyle.Information, "Required Fiels")
Exit Sub
End If
With aAdapter
.SelectCommand = New OleDb.OleDbCommand()
.SelectCommand.CommandText = "select * from [vote] where username = '" & user.Text & "'"
.SelectCommand.Connection = con
End With
Dim dataRead As OleDb.OleDbDataReader
dataRead = aAdapter.SelectCommand.ExecuteReader()
If Not dataRead.HasRows Then
ComInsert.CommandText = "INSERT INTO vote([username],[president],[vicePresident],[secretary],[treasurer])" & _
"VALUES('" & user.Text & "','" & presbox.Text & "','" & vpbox.Text & "','" & secbox.Text & "','" & treasbox.Text & "')"
ComInsert.Connection = con
ComInsert.ExecuteNonQuery()
MsgBox("Voting Successful!", MsgBoxStyle.Information, "NEW RECORD")
Form1.Show()
Me.Close()
aAdapter.Dispose()
ComInsert.Dispose()
Else
MsgBox("WARNING: User Voted Already!!", MsgBoxStyle.Exclamation, "ERROR SAVING DATA")
Me.Close()
Form1.Show()
End If
Catch ex As Exception
End Try
End Sub
End Class
你想要做什么?你想知道是否选择了组合框中的项目吗? –
JLott selectedIndexChanged是一个很好的答案,但是我更愿意使用JavaScript来提高页面响应能力,并且如果您已经在HTML中具有想要放入文本框的值,那么我将使用HTML选择元素OnChange事件,请在此处查看:http ://www.w3schools.com/jsref/event_onchange.asp – Jportelas
的确,我从VB的角度来看它,而不是网络的一面。 – JLott