将图像存储到数据库Blob；从数据库检索到Picturebox

Question

您好，我在较早之前发布了此内容，并获得了一些帮助，但仍然没有有效的解决方案。由于最后的问与答，我确定我的“保存到数据库”代码以及“检索到图片”代码有问题。即使我手动将图片保存在数据库中，它也不会恢复。这是我从网络上的3或4个示例中修补而成的代码。理想情况下，如果有人拥有一些已知的良好代码，并且可以指导我这样做，那将是最好的。

    Dim filename As String = txtName.Text + ".jpg"

    Dim FileSize As UInt32

    Dim ImageStream As System.IO.MemoryStream

    ImageStream = New System.IO.MemoryStream

    PbPicture.Image.Save(ImageStream, System.Drawing.Imaging.ImageFormat.Jpeg)

    ReDim rawdata(CInt(ImageStream.Length - 1))

    ImageStream.Position = 0

    ImageStream.Read(rawdata, 0, CInt(ImageStream.Length))

    FileSize = ImageStream.Length

    Dim query As String = ("insert into actors (actor_pic, filename, filesize) VALUES    (?File, ?FileName, ?FileSize)")

    cmd = New MySqlCommand(query, conn)

    cmd.Parameters.AddWithValue("?FileName", filename)

    cmd.Parameters.AddWithValue("?FileSize", FileSize)

    cmd.Parameters.AddWithValue("?File", rawData)

    cmd.ExecuteNonQuery()

    MessageBox.Show("File Inserted into database successfully!", _

    "Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)

！[在此处输入图片描述] [1]

' * **使用以下代码接收到图片框：

  Private Sub GetPicture()

    'This retrieves the pictures from a mysql DB and buffers the rawdata into a memorystream 

    Dim FileSize As UInt32

    Dim rawData() As Byte

    Dim conn As New MySqlConnection(connStr)

    conn.Open()

    conn.ChangeDatabase("psdb")

    Dim cmd As New MySqlCommand("SELECT actor_pic, filesize, filename FROM actors WHERE actor_name = ?autoid", conn)

    Cmd.Parameters.AddWithValue("?autoid", Actor1Box.Text)

    Reader = cmd.ExecuteReader

    Reader.Read()

    'data is in memory 

    FileSize = Reader.GetUInt32(Reader.GetOrdinal("filesize"))

    rawData = New Byte(FileSize) {}

    'get the bytes and filesize 

    Reader.GetBytes(Reader.GetOrdinal("actor_pic"), 0, rawData, 0, FileSize)

    Dim ad As New System.IO.MemoryStream(100000)

    ' Dim bm As New Bitmap

    ad.Write(rawData, 0, FileSize)