Store image to database blob; retrieve from db into Picturebox
Hi I posted this earlier and got some help but still no working solution. I have determined thanks to the last q & a that there is something wrong with my "save to db" code as well as my "retrieve to picture" code. Even If I manually save the pic in the db it stil wont retreive. This is code i patched together from 3 or 4 examples around the net. Ideally if someone had some known good code and could direct me to it that would be the best.
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)
![enter image description here][1]
'*****retieving to the picturebox using the following code:
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(开发者_StackOverflow社区"actor_pic"), 0, rawData, 0, FileSize)
Dim ad As New System.IO.MemoryStream(100000)
' Dim bm As New Bitmap
ad.Write(rawData, 0, FileSize)
Dim im As Image = Image.FromStream(ad) * "error occurs here" (see below)
Actor1Pic.Image = im
Reader.Close()
conn.Close()
conn.Dispose()
ad.Dispose()
Well since getting no help i bashed away at the problem and got it to work finally. Here is my working code.
SAVE TO MySQL out of Picturebox (pbPicture)
Dim filename As String = txtName.Text + ".jpg"
Dim FileSize As UInt32
conn.Close()
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)"
Try
conn.Open()
With sqlcmd
.CommandText = sql
.Connection = conn
.Parameters.AddWithValue("@FileName", filename)
.Parameters.AddWithValue("@FileSize", FileSize)
.Parameters.AddWithValue("@File", arrImage)
.ExecuteNonQuery()
End With
Catch ex As Exception
MsgBox(ex.Message)
Finally
conn.Close()
End Try
LOAD from MySQL db Back to Picturebox
Dim adapter As New MySqlDataAdapter
adapter.SelectCommand = Cmd
data = New DataTable
adapter = New MySqlDataAdapter("select picture from [yourtable]", conn)
NOTE!! can only put one picture in picturebox so obviously this query can only return one record for you
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()
The accepted and upvoted answer may work, but it is suboptimal and quite wasteful:
- If the image to save is on disk, there is no reason to use a UI control and a
MemoryStream
to get the image into a byte array. - The code also appears to reuse a single global connection object; these should be created and disposed of rather than reused.
- Consider saving just the file name to the database, perhaps hashed, with the image saved to a special folder. Saving image data bloats the DB and takes longer to convert.
- Finally,
.GetBuffer()
is quite incorrect:
The memstream buffer will often include unused, allocated bytes. With a 25k test file,ToArray()
returns 25434 bytes - the correct size of the image - whileGetBuffer()
returns 44416. The larger the image, the more empty bytes there will be.
This uses MySQL provider objects since it is so-tagged, but the data provider (MySQL, SQLServer, OleDB etc) used doesnt matter: they all work the same.
In cases where the image source is a PictureBox, use a MemoryStream
:
Dim picBytes As Byte()
Using ms As New MemoryStream()
picBox1.Image.Save(ms, imgFormat)
picBytes = ms.ToArray() ' NOT GetBuffer!
End Using
Since the image had to come from somewhere, if it is a file, this is all you need:
picBytes = File.ReadAllBytes(filename)
Once you have the image as bytes, to save:
Dim SQL = "INSERT INTO <YOUR TBL NAME> (picture, filename, filesize) VALUES(@Pic, @FileName, @FileSize)"
Using conn As New MySqlConnection(connstr)
Using cmd As New MySqlCommand(SQL, conn)
conn.Open()
cmd.Parameters.Add("@Pic", MySqlDbType.Blob).Value = picBytes
cmd.Parameters.Add("@FileName", MySqlDbType.String).Value = filename
cmd.Parameters.Add("@FileSize", MySqlDbType.Int32).Value = FileSize
cmd.ExecuteNonQuery()
End Using
End Using ' close and dispose of Connection and Command objects
Loading Image from DB
Dim imgData As Byte()
'... open connection, set params etc
Using rdr As MySqlDataReader = cmd.ExecuteReader
If rdr.HasRows Then
rdr.Read()
imgData = TryCast(rdr.Item("Image"), Byte())
' in case this record has no image
If imgData IsNot Nothing Then
' ToDo: dispose of any previous Image
' create memstream from bytes
Using ms As New MemoryStream(imgData)
' create image from stream, assign to PicBox
picBox1.Image = CType(Image.FromStream(ms), Image)
End Using
End If
End If
End Using
Note that Bitmaps
and Images
must be disposed of. If you repeatedly create new images as the user browses the database your app will leak and eventually crash. If you convert back and forth a lot, you can write a helper or extension method to convert images to bytes and vice versa.
DBConnection
and DBCommand
objects also need to be disposed of. The Using
block does this for us.
References, Resources:
- Reuse or Dispose DB Connections? sample
GetConnection
helper - Connection Pooling
- MemoryStream.GetBuffer()
- Can we stop using AddWithValue()
Tested Code for Store and Retrieve Images using MySQL and VB.NET
Public Class FMImage
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If OpenFileDialog1.ShowDialog(Me) = Windows.Forms.DialogResult.OK Then
TextBox1.Text = OpenFileDialog1.FileName
Dim filename As String = TextBox1.Text
Dim FileSize As UInt32
Dim Conn As MySql.Data.MySqlClient.MySqlConnection
Conn = New MySql.Data.MySqlClient.MySqlConnection
Try
If Conn.State = ConnectionState.Open Then Conn.Close()
Conn.ConnectionString = MySQLConnectionString
Conn.Open()
Catch ex As Exception
MessageBox.Show(ex.ToString, "Connect")
End Try
Dim mstream As System.IO.MemoryStream = ConvertImageFiletoMemoryStream(filename)
PbPicture.Image.Save(mstream, Drawing.Imaging.ImageFormat.Jpeg)
Dim arrImage() As Byte = ConvertImageFiletoBytes(filename)
FileSize = mstream.Length
Dim sqlcmd As New MySql.Data.MySqlClient.MySqlCommand
Dim sql As String
mstream.Close()
'CREATE TABLE `actors` ( `actor_pic` longblob,`filesize` bigint(20) default NULL,`filename` varchar(150) default NULL) ENGINE=InnoDB DEFAULT CHARSET=latin1;
sql = "insert into actors (actor_pic, filesize, filename) VALUES(@File, @FileName, @FileSize)"
Try
With sqlcmd
.CommandText = sql
.Connection = Conn
.Parameters.AddWithValue("@FileName", filename)
.Parameters.AddWithValue("@FileSize", FileSize)
.Parameters.AddWithValue("@File", arrImage)
.ExecuteNonQuery()
End With
Catch ex As Exception
MsgBox(ex.Message)
End Try
Dim adapter As New MySql.Data.MySqlClient.MySqlDataAdapter
adapter.SelectCommand = New MySql.Data.MySqlClient.MySqlCommand("SELECT actor_pic, filesize, filename FROM actors", Conn)
Dim Data As New DataTable
'adapter = New MySql.Data.MySqlClient.MySqlDataAdapter("select picture from [yourtable]", Conn)
Dim commandbuild As New MySql.Data.MySqlClient.MySqlCommandBuilder(adapter)
adapter.Fill(Data)
MsgBox(Data.Rows.Count)
Dim lb() As Byte = Data.Rows(Data.Rows.Count - 1).Item("actor_pic")
Dim lstr As New System.IO.MemoryStream(lb)
PbPicture.Image = Image.FromStream(lstr)
PbPicture.SizeMode = PictureBoxSizeMode.StretchImage
lstr.Close()
End If
End Sub
Public Function ConvertImageFiletoBytes(ByVal ImageFilePath As String) As Byte()
Dim _tempByte() As Byte = Nothing
If String.IsNullOrEmpty(ImageFilePath) = True Then
Throw New ArgumentNullException("Image File Name Cannot be Null or Empty", "ImageFilePath")
Return Nothing
End If
Try
Dim _fileInfo As New IO.FileInfo(ImageFilePath)
Dim _NumBytes As Long = _fileInfo.Length
Dim _FStream As New IO.FileStream(ImageFilePath, IO.FileMode.Open, IO.FileAccess.Read)
Dim _BinaryReader As New IO.BinaryReader(_FStream)
_tempByte = _BinaryReader.ReadBytes(Convert.ToInt32(_NumBytes))
_fileInfo = Nothing
_NumBytes = 0
_FStream.Close()
_FStream.Dispose()
_BinaryReader.Close()
Return _tempByte
Catch ex As Exception
Return Nothing
End Try
End Function
Public Function ConvertBytesToMemoryStream(ByVal ImageData As Byte()) As IO.MemoryStream
Try
If IsNothing(ImageData) = True Then
Return Nothing
'Throw New ArgumentNullException("Image Binary Data Cannot be Null or Empty", "ImageData")
End If
Return New System.IO.MemoryStream(ImageData)
Catch ex As Exception
Return Nothing
End Try
End Function
Public Function ConvertImageFiletoMemoryStream(ByVal ImageFilePath As String) As IO.MemoryStream
If String.IsNullOrEmpty(ImageFilePath) = True Then
Return Nothing
' Throw New ArgumentNullException("Image File Name Cannot be Null or Empty", "ImageFilePath")
End If
Return ConvertBytesToMemoryStream(ConvertImageFiletoBytes(ImageFilePath))
End Function
End Class
I am having problem using mr @dMo 's program its showing me an error "Column 'picture' cannot be null"
here is my code.
Private Sub ButtonSave_Click(sender As Object, e As EventArgs) Handles ButtonSave.Click
Dim filename As String = TextBoxSave.Text + ".jpg"
Dim FileSize As UInt32
conn.Close()
Dim mstream As New System.IO.MemoryStream()
PictureBoxSave.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 employeedetails (picture,filename,filesize) VALUES(@File, @FileName, @FileSize)")
Try
conn.Open()
With sqlcmd
.CommandText = sql
.Connection = conn
.Parameters.AddWithValue("@FileName", filename)
.Parameters.AddWithValue("@FileSize", FileSize)
.Parameters.AddWithValue("@File", arrImage)
.ExecuteNonQuery()
End With
Catch ex As Exception
MsgBox(ex.Message)
Finally
conn.Close()
End Try
End Sub
P.S. Im sorry for posting this adnand answer I have no enough reputation to comment to this post
The code below inserts a record of vehicle information in a table. The Image of the car selected is converted into memory stream and saved to the Database as Varbinary.
A function is used to convert the image to memory stream.
' Upload new vehicle image
Private Sub BtnUpload_Click(sender As Object, e As EventArgs) Handles
BtnUpload.Click
Dim imgBinary As Byte()
With Me.OpenFileDialog1
.FileName = ""
.Filter = "Image Files(*.BMP;*.JPG;*.JEPG;*.GIF)|*.BMP;*.JPG;*.JEPG;*.GIF|All files (*.*)|*.*"
.RestoreDirectory = True
.ValidateNames = True
.CheckFileExists = True
If .ShowDialog = Windows.Forms.DialogResult.OK Then
'Me.PicImage.Image.Dispose()
Me.PicImage.Image = System.Drawing.Image.FromFile(.FileName)
End If
End With
imgBinary = ConvertImage(PicImage.Image)
Dim command As New SqlCommand("insert into MyCars(CarId, Manufacture, CarModel, CarClass, CarImage) values(@CarId, @Manufacture, @CarModel, @CarClass, @CarImage)", connection)
command.Parameters.Add("@CarId", SqlDbType.VarChar).Value = CInt(TxtID.Text)
command.Parameters.Add("@Manufacture", SqlDbType.VarChar).Value = TxtManufacturer.Text
command.Parameters.Add("@CarModel", SqlDbType.VarChar).Value = TxtModel.Text
command.Parameters.Add("@CarClass", SqlDbType.VarChar).Value = TxtClass.Text
command.Parameters.Add("@CarImage", SqlDbType.VarBinary).Value = imgBinary
Try
connection.Open()
If command.ExecuteNonQuery() = 1 Then
MessageBox.Show("Car # " & TxtID.Text & " successfully added to database.")
Else
MessageBox.Show("Car not added!")
End If
Catch ex As Exception
MessageBox.Show("Error while inserting record on table..." & ex.Message, "Insert Records")
Finally
connection.Close()
End Try
End Sub
The following function converts the image into memory stream.
' Convert Image from Memory Stream
Public Function ConvertImage(ByVal myImage As Image) As Byte()
Dim mstream As New MemoryStream
myImage.Save(mstream, System.Drawing.Imaging.ImageFormat.Jpeg)
Dim myBytes(mstream.Length - 1) As Byte
mstream.Position = 0
mstream.Read(myBytes, 0, mstream.Length)
Return myBytes
End Function
The code below is used to display the image from the database. Use the ID (as an integer) to display the image.
Private Sub BtnShowImg_Click(sender As Object, e As EventArgs) Handles BtnShowImg.Click
Dim command As New SqlCommand("select * from MyCars where CarId = @CarId", connection)
command.Parameters.Add("CarId", SqlDbType.VarChar).Value = TxtID.Text
Dim table As New DataTable()
Dim adapter As New SqlDataAdapter(command)
adapter.Fill(table)
If table.Rows.Count <= 0 Then
MessageBox.Show("No Image for the Selected Id")
Else
TxtID.Text = table.Rows(0)(0).ToString() ' Col 0 = CarId
TxtManufacturer.Text = table.Rows(0)(1).ToString() ' Col 1 = Manufacturer
TxtModel.Text = table.Rows(0)(2).ToString ' Col 2 = Model
TxtClass.Text = table.Rows(0)(3).ToString() ' Col 3 = Vehicle Class
Dim img() As Byte
img = table.Rows(0)(4) ' Col 4 = Img
Dim ms As New MemoryStream(img)
PicImage.Image = Image.FromStream(ms)
End If
End Sub
Interface - Hope It Helps
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