Question

使用此代码，抛出索引超出范围错误，建议？添加了整个代码。在选择列表框项目时，仅将最后一项输入到数据库中。我怀疑它与代码末尾的受影响的整数和受影响的调用有关。

Dim Affected As Integer = 0

    Dim Builder As New OleDb.OleDbConnectionStringBuilder With
        {
            .Provider = "Microsoft.ACE.OLEDB.12.0",
            .DataSource = IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "CalcDB.accdb"),
            .PersistSecurityInfo = False
        }



    Using cn As New OleDb.OleDbConnection With {.ConnectionString = Builder.ConnectionString}
        Using cmd As New OleDb.OleDbCommand With {.Connection = cn}
            cmd.CommandText =
                <SQL>
                INSERT INTO CalcOps 
                (
                    NumOne, 
                    Operation, 
                    NumTwo,
                    Equal,
                    Result
                ) 
                VALUES 
                (
                    @NumOne, 
                    @Operation, 
                    @NumTwo, 
                    @Equal,
                    @Result
                )
            </SQL>.Value

            With cmd.Parameters

                .AddWithValue("@NumOne", NumOne.Text)
                .AddWithValue("@Operation", ListBox1.Tag)
                .AddWithValue("@NumTwo", NumTwo.Text)
                .AddWithValue("@Equal", "=")
                .AddWithValue("@Result", Result.Text)

            End With

            Dim x As Integer

            For x = 0 To ListBox1.Items.Count - 1
                If ListBox1.GetSelected(x) = False Then
                    ListBox1.SetSelected(x, True)
                End If
            Next


            Try
                cn.Open()
                Affected = cmd.ExecuteNonQuery

            Catch ex As Exception
                MessageBox.Show("Problem:" & Environment.NewLine & ex.Message)
            End Try

        End Using
    End Using

    If Affected = 1 Then
        MessageBox.Show("Insert done")
    Else
        MessageBox.Show("Insert failed")
    End If


End Sub

Answer 1

您需要将If语句放在循环中。 x循环变量仅在循环内递增或递减，具体取决于Step。

For x As Integer = 0 To ListBox1.Items.Count - 1
  If ListBox1.GetSelected(x) = False Then
    ListBox1.SetSelected(x, True)
  End If
Next

ListBox选择所有循环

1 个答案: