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将图像存储到数据库Blob;从数据库检索到Picturebox

将图像存储到数据库Blob;从数据库检索到Picturebox

偶然的你 2019-12-06 14:42:59
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)
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