How to Store and Retrieve Images in a Database for PictureBox Display?-Mysql Tutorial-php.cn

How to Store and Retrieve Images in a Database for PictureBox Display?

Barbara Streisand

Release： 2024-11-21 08:44:12

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How to Store and Retrieve Images in a Database for PictureBox Display?

Image Storage and Retrieval for Picturebox Using Database Blob

Overview

This article addresses the issue of storing images as blobs in a database and retrieving them to display in a Picturebox control.

Inserting Image Data into Database

To store an image in a database, the first step is to convert it into a binary format. This can be achieved using the Save method with the appropriate ImageFormat parameter.

Here's an example of inserting image data into a database:

Dim filename As String = txtName.Text + ".jpg"
Dim FileSize As UInt32
Dim mstream As New System.IO.MemoryStream()
PbPicture.Image.Save(mstream, System.Drawing.Imaging.ImageFormat.Jpeg)
Dim arrImage() As Byte = mstream.GetBuffer()
FileSize = mstream.Length
Dim sqlcmd As New MySqlCommand
Dim sql As String
mstream.Close()

sql = "insert into [your table]  (picture, filename, filesize) VALUES(@File, @FileName,   @FileSize)"

conn.Open()

With sqlcmd
  .CommandText = sql
  .Connection = conn
  .Parameters.AddWithValue("@FileName", filename)
  .Parameters.AddWithValue("@FileSize", FileSize)
  .Parameters.AddWithValue("@File", arrImage)
  .ExecuteNonQuery()
End With

conn.Close()

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Retrieving Image Data from Database

To retrieve an image from the database and display it in a Picturebox, follow these steps:

Dim adapter As New MySqlDataAdapter
adapter.SelectCommand = Cmd
data = New DataTable
adapter = New MySqlDataAdapter("select picture from [yourtable]", conn)
commandbuild = New MySqlCommandBuilder(adapter)
adapter.Fill(data)
Dim lb() As Byte = data.Rows(0).Item("picture")
Dim lstr As New System.IO.MemoryStream(lb)
PbPicture.Image = Image.FromStream(lstr)
PbPicture.SizeMode = PictureBoxSizeMode.StretchImage
lstr.Close()

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By implementing these methods, you can seamlessly store and retrieve images in and from a database for display in Picturebox controls.

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