在VB中读取Blob到图片框

Question

我搞砸了这一点并尝试跟随网上的其他每个例子，但我似乎无法将一个blob图像从MySql DB中拉到图片框中。最后，我希望能够在图片框中显示图片，并让用户能够使用另存为对话框将图片保存到他们的计算机。这是我到目前为止，我的错误是当我尝试将图片实际放在“picShowPicture.image = Image.FromStream”的图片框中时，任何帮助都将不胜感激。

    Imports MySql.Data.MySqlClient
    Imports System.IO
    Imports System.Drawing
    Imports System.Drawing.Imaging
    Imports System.Drawing.Drawing2D
    Imports System.Data
    Imports System.Windows.Forms

    Dim cn As New MySqlConnection
    Dim constring As String
    constring = "server=localhost;User Id=uid;password=pass;database=default"

    Dim cmd As New MySqlCommand
    Dim cmdtxt As String
    cmdtxt = "SELECT picture FROM test WHERE serial = '" & txtSerial.Text & "'"
    With cmd
        .Connection = cn
        .CommandText = cmdtxt
        .CommandType = CommandType.Text
    End With

    cn.ConnectionString = constring
    cn.Open()

    Dim da As New MySqlDataAdapter(cmd)
    Dim ds As New DataSet()
    da.Fill(ds, "test")
    Dim c As Integer = ds.Tables("test").Rows.Count
    If c > 0 Then
        Dim bytBLOBData() As Byte = _
            ds.Tables("test").Rows(c - 1)("picture")
        Dim stmBLOBData As New MemoryStream(bytBLOBData)
        picShowPicture.Image = Image.FromStream(stmBLOBData)
    End If