Question

美好的一天......我很难弄清楚代码上的问题是什么

我的添加记录按钮按钮实际上正常工作，＆＃34; BUT＆＃34;问题是

•在文本上放入错误的数据后，即使我已经输入了正确的数据，也会反复出现错误..

   Imports System.Data.OleDb
Imports System.IO
Public Class Form1
    Dim conn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\Charles\Documents\Database1.accdb")
    Dim cmd As New OleDb.OleDbCommand
    Dim dt As DataTable
    Dim dr As OleDbDataReader

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        fillListView()
    End Sub
    Private Sub fillListView()
        conn.Open()
        With cmd
            .Connection = conn
            .CommandText = "Select * From Employee"
        End With
        ListView1.Items.Clear()
        dr = cmd.ExecuteReader
        While dr.Read
            With ListView1
                .Items.Add(dr.Item(0))
                With .Items(.Items.Count - 1).SubItems
                    .Add(dr(1))
                    .Add(dr(2))
                    .Add(dr(3))
                    .Add(dr(4))
                    .Add(dr(5))
                End With
            End With
        End While
        conn.Close()
    End Sub
    Public Sub clearAll()
        txtName.Clear()
        txtSSS.Clear()
        txtTIN.Clear()
        txtSalary.Clear()
    End Sub
    Private Sub ListView1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListView1.Click
        txtName.Text = ListView1.SelectedItems.Item(0).SubItems(1).Text
        txtSSS.Text = ListView1.SelectedItems.Item(0).SubItems(2).Text
        txtTIN.Text = ListView1.SelectedItems.Item(0).SubItems(3).Text
        txtTIN.Text = ListView1.SelectedItems.Item(0).SubItems(5).Text
    End Sub
    Public Sub enableTxtBox()
        txtName.Enabled = True
        txtSSS.Enabled = True
        txtTIN.Enabled = True
        dtpED.Enabled = True
        txtSalary.Enabled = True
    End Sub

    Public Sub disableTxtBox()
        txtName.Enabled = False
        txtSSS.Enabled = False
        txtTIN.Enabled = False
        dtpED.Enabled = False
        txtSalary.Enabled = False
    End Sub
    Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        enableTxtBox()
    End Sub

    Private Sub btnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClose.Click
        Dim Response As Integer
        Response = MessageBox.Show("Do you really want to exit?", "", _
        MessageBoxButtons.YesNo, MessageBoxIcon.Question)
        If Response = vbYes Then
            Me.Close()
        End If
    End Sub

    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        Try
            conn.Open()
            cmd.CommandText = "INSERT INTO Employee(EmployeeName,SSS,TIN,ED,Salary) Values(@EmployeeName,@SSS,@TIN,@ED,@Salary)"
            cmd.Parameters.AddWithValue("@EmployeeName", txtName.Text)
            cmd.Parameters.AddWithValue("@SSS", txtSSS.Text)
            cmd.Parameters.AddWithValue("@TIN", txtTIN.Text)
            cmd.Parameters.AddWithValue("@ED", dtpED.Text)
            cmd.Parameters.AddWithValue("@Salary", txtSalary.Text)
            cmd.ExecuteNonQuery()
            conn.Close()
            fillListView()
            clearAll()
        Catch ex As Exception
            MsgBox("Error")
        End Try

    End Sub
    End Sub


End Class

Answer 1

您没有看到类似错误消息的原因是因为您根本没有使用Exceptions。

在这部分代码中：

Catch ex As Exception
   MsgBox("Error")
End Try

您已宣布Exception，但实际上您从未使用过它要调用Exception，你应该写下这部分代码：

Catch ex As Exception
   MsgBox(ex.message)
End Try

现在您可以看到，如果您进入Catch，MsgBox将显示异常，您将能够阅读实际错误。

Answer 2

谢谢大家我刚刚解决了我的问题...

修复了我的fillListiew（）

代码

Private Sub fillListView()
    Dim dt As New DataTable
    Dim ds As New DataSet
    ds.Tables.Add(dt)

    Dim da As New OleDbDataAdapter("SELECT * FROM Employee", conn)
    da.Fill(dt)
    ListView1.Items.Clear()
    Dim newRow As DataRow
    For Each newRow In dt.Rows
        ListView1.Items.Add(newRow.Item(0))
        ListView1.Items(ListView1.Items.Count - 1).SubItems.Add(newRow(1))
        ListView1.Items(ListView1.Items.Count - 1).SubItems.Add(newRow(2))
        ListView1.Items(ListView1.Items.Count - 1).SubItems.Add(newRow(3))
        ListView1.Items(ListView1.Items.Count - 1).SubItems.Add(newRow(4))
        ListView1.Items(ListView1.Items.Count - 1).SubItems.Add(newRow(5))
    Next
End Sub

添加记录VB .Net的问题

2 个答案: