Question

我在我的vb.net项目中遵循了代码与sql db的连接很好＆amp;好的，只有当我尝试填充列表框时才会收到错误

Public Class Form1
    Private myTable As New DataTable()

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

    '------------
    myTable.Columns.Add("naam", GetType(String))
    myTable.Columns.Add("waarde", GetType(Integer))   '<<<< change the type of this column to what you actually need instead of integer.


    ListBox1.DisplayMember = "naam"
    ListBox1.ValueMember = "waarde"
    ListBox1.DataSource = myTable

End Sub

和

Private Sub FillListBox()
    Dim naam As String
    Dim stringConn As String
    Dim stringCmd As String
    Dim myConn As MySqlConnection
    Dim myCmd As MySqlCommand

    'Frame your query here.
    stringCmd = "SELECT id,naam,voornaam FROM deelnemers WHERE finger = FALSE ORDER BY naam "

    'Frame your connection string here.
    stringConn = "********************************************"

    'Get your connection here.
    myConn = New MySqlConnection(stringConn)

    'Get a command by using your connection and query.
    myCmd = New MySqlCommand(stringCmd, myConn)

    'Open the connection.
    myConn.Open()

    'create a reader to store the datum which will be returned from the DB
    Dim myReader As MySqlDataReader

    'Execute your query using .ExecuteReader()
    myReader = myCmd.ExecuteReader()

    'Reset your List box here.
    ListBox2.Items.Clear()

    While (myReader.Read())
        'Add the items from db one by one into the list box.
        naam = myReader.GetString(1) & " " & myReader.GetString(2)
        'ListBox2.Items.Add((naam))
        myTable.Rows.Add(naam, myReader.GetString(0))
    End While

    'Close the reader and the connection.
    myReader.Close()
    myConn.Close()

End Sub

我在后续行中收到错误

myTable.Rows.Add(naam, myReader.GetString(0))

具有以下描述：输入数组比此表中的列数长。

有人看到了吗？

Answer 1

我怀疑你的myTable数据表没有任何列......

尝试更改：

While (myReader.Read())
    'Add the items from db one by one into the list box.
    naam = myReader.GetString(1) & " " & myReader.GetString(2)
    'ListBox2.Items.Add((naam))
    myTable.Rows.Add(naam, myReader.GetString(0))
End While

到此：

Dim row As DataRow
While (myReader.Read())
    'Add the items from db one by one into the list box.
    row = myTable.NewRow()
    row("naam") = myReader.GetString(1) & " " & myReader.GetString(2)
    row("waarde") = myReader.GetString(0)
    myTable.Rows.Add(row)
End While

你仍然会收到错误，但至少这样你就会知道哪些列丢失了......

<强>更新

另外，改变这个：

FillListBox()

'------------
myTable.Columns.Add("naam", GetType(String))
myTable.Columns.Add("waarde", GetType(Integer))   '<<<< change the type of this column to what you actually need instead of integer.

到此：

'------------
myTable.Columns.Add("naam", GetType(String))
myTable.Columns.Add("waarde", GetType(Integer))   '<<<< change the type of this column to what you actually need instead of integer.

FillListBox()

vb.net：输入数组比此表中的列数长

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