vb.net Postgresql数据库，使用DataTable并在Datagridview中显示位图

Imports System.Data
Imports Npgsql

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 建立与PostgreSQL数据库的连接
        Dim connString As String = "Host=localhost;Port=5432;Database=mydb;Username=myuser;Password=mypassword"
        Using conn As New NpgsqlConnection(connString)
            conn.Open()

            ' 查询位图数据
            Dim sql As String = "SELECT bitmap_data FROM bitmaps"
            Using cmd As New NpgsqlCommand(sql, conn)
                Using reader As NpgsqlDataReader = cmd.ExecuteReader()
                    ' 创建DataTable
                    Dim dt As New DataTable()
                    dt.Columns.Add("Bitmap", GetType(Byte()))

                    ' 将位图数据添加到DataTable中
                    While reader.Read()
                        Dim bitmapData As Byte() = DirectCast(reader("bitmap_data"), Byte())
                        dt.Rows.Add(bitmapData)
                    End While
                    reader.Close()

                    ' 将DataTable绑定到DataGridView
                    DataGridView1.DataSource = dt
                End Using
            End Using
        End Using
    End Sub
End Class