如何在Visual Basic 2012中使用mdb数据库中的数据填充列表框？

Posted 2021-04-18

我正在使用Visual Basic 2012制作学生档案以进行计算任务。

我有一个组合框，里面有两门课程：计算机和商务。 （在表格的右侧，附图）。此外，按下的列表按钮应根据组合框中选择的课程显示.mdb数据库中的学生。

如何使用我的数据库中的学生填充列表框（我有）？

以下更准确的是我到目前为止的代码：

Public Class Form1 Dim co As New ADODB.Connection Dim rs As New ADODB.Recordset Dim confirm As Integer

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    co.Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:DocumentsProfileDB.mdb;Persist Security Info=False")
    rs.Open("Select * from ProfileTBL", co, ADODB.CursorTypeEnum.adOpenDynamic, ADODB.LockTypeEnum.adLockPessimistic)
    Combo1.Items.Add("Computer Technology")
    Combo1.Items.Add("Business Management")
    display()
End Sub

Sub display()
    TextBox1.Text = rs.Fields.Item("FirstName").Value
    TextBox2.Text = rs.Fields.Item("Surname").Value
    Combo1.Text = rs.Fields.Item("Course").Value
    TextBox4.Text = rs.Fields.Item("Phone").Value
End Sub


Private Sub addnew_Click(sender As Object, e As EventArgs) Handles addnew.Click
    rs.AddNew()
    clear()
End Sub

Sub clear()
    TextBox1.Text = ""
    TextBox2.Text = ""
    Combo1.Text = "Select Course"
    TextBox4.Text = ""
End Sub

Private Sub Savebtn_Click(sender As Object, e As EventArgs) Handles Savebtn.Click
    rs.Fields("FirstName").Value = TextBox1.Text
    rs.Fields("Surname").Value = TextBox2.Text
    rs.Fields("Course").Value = Combo1.Text
    rs.Fields("Phone").Value = TextBox4.Text
    MsgBox("Data is saved successfully.", vbInformation)
    rs.Update()
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    rs.MovePrevious()
    If rs.BOF Then
        rs.MoveLast()
        display()
    Else
        display()
    End If
End Sub


Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    rs.MoveNext()
    If Not rs.EOF Then
        display()
    Else
        rs.MoveFirst()
        display()
    End If
End Sub

Private Sub deletebtn_Click(sender As Object, e As EventArgs) Handles deletebtn.Click
    confirm = MsgBox("Do you want to delete the Student Profile", vbYesNo + vbCritical, "Deletion Confirmation")
    If confirm = vbYes Then
        rs.Delete()
        MsgBox("Record has been Deleted successfully", vbInformation, "Message")
        rs.Update()
        Refresh()
        clear()

    Else
        MsgBox("Profile Not Deleted!", vbInformation, "Message")
    End If
End Sub



Private Sub findbtn_Click(sender As Object, e As EventArgs) Handles findbtn.Click
    rs.Close()
    rs.Open("Select * from ProfileTBL where Phone='" + TextBox4.Text + "'", co, ADODB.CursorTypeEnum.adOpenDynamic, ADODB.LockTypeEnum.adLockPessimistic)
    If Not rs.EOF Then
        display()
        reload()
    Else
        MsgBox("Record Profile not found!", vbInformation)
    End If

End Sub

Sub reload()
    rs.Close()
    rs.Open("Select * from ProfileTBL", co, ADODB.CursorTypeEnum.adOpenDynamic, ADODB.LockTypeEnum.adLockPessimistic)
End Sub


Private Sub listbtn_Click(sender As Object, e As EventArgs) Handles listbtn.Click


End Sub

结束班

答案

可能如下：

Private Sub btnListStudents_Click(sender As Object, e As EventArgs) Handles btnListStudents.Click
    Dim dt As New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("StudentId", GetType(Integer)),
                                           New DataColumn("StudentName", GetType(String)),
                                           New DataColumn("StudentCourse", GetType(Integer))})
    dt.Rows.Add(1, "John Hammond", 555)
    dt.Rows.Add(2, "Mudassar Khan", 666)
    dt.Rows.Add(3, "Suzanne Mathews", 777)
    dt.Rows.Add(4, "Robert Schidner", 888)
    dt.Rows.Add(5, "John Doo", 999)

    'Clear first
    lstStudents.Items.Clear()

    'Fill names into the listbox
    For Each row As DataRow In dt.Rows
        lstStudents.Items.Add(row("StudentName"))
    Next row
End Sub