Loading image from database to picturebox - sql

Question

I'm new to visual basic and I have a problem in loading the image from my database. I'm currently using image data type. This is how I save the image
Imports System.Data
Imports System.Data.SqlClient
Public Class ScannerX_Add
Dim ImageFilename As String
Dim ImageUpload As Image
Private Sub ButtonX1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btn_Scan.Click
Try
OpenFileDialog1.Title = "Please Select a File"
OpenFileDialog1.InitialDirectory = "C:\Users\ITTestServer\Desktop\Dekstop\"
OpenFileDialog1.ShowDialog()
ScannerX_Pic.Image = Image.FromFile(OpenFileDialog1.FileName)
ImageFilename = OpenFileDialog1.FileName
ImageUpload = Image.FromFile(OpenFileDialog1.FileName)
Catch ex As Exception
MsgBox("Please insert scan finger")
Exit Sub
End Try
End Sub
Private Sub Btn_Save_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btn_Save.Click
If ImageFilename <> "" Then
Dim imageNameTemp As String
imageNameTemp = ImageFilename
While (imageNameTemp.Contains("\"))
imageNameTemp = imageNameTemp.Remove(0, imageNameTemp.IndexOf("\") + 1)
End While
Dim ms As New IO.MemoryStream
If ImageFilename.Contains("jpeg") Or ImageFilename.Contains("jpg") Then
ImageUpload.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg)
End If
If ImageFilename.Contains("png") Then
ImageUpload.Save(ms, System.Drawing.Imaging.ImageFormat.Png)
End If
If ImageFilename.Contains("gif") Then
ImageUpload.Save(ms, System.Drawing.Imaging.ImageFormat.Gif)
End If
If ImageFilename.Contains("bmp") Then
ImageUpload.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp)
End If
Dim b() As Byte = ms.ToArray()
Dim cmd As New SqlCommand("Insert into Scanner (Name,Finger) VALUES('" & TxtBox_Name.Text.Trim & "','" & imageNameTemp & "')", Connection)
cmd.Parameters.Add("#BLOBData", SqlDbType.Image, b.Length).Value = b
cmd.ExecuteNonQuery()
MsgBox("Profile Has Been Saved")
Me.Close()
End If
End Sub
Now I need to load my image to picturebox which is currently in the Main form.
Private Sub ButtonX1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonX1.Click
Command.CommandText = ("select Finger FROM Scanner")
Command.Connection = Connection
Dim da As New SqlDataAdapter(Command)
Dim ds As New DataSet()
da.Fill(ds, "projectimages")
Dim c As Integer = ds.Tables(0).Rows.Count
If c > 0 Then
Dim bytBLOBData() As Byte = _
ds.Tables(0).Rows(c - 1)("imagedate")
Dim stmBLOBData As New MemoryStream(bytBLOBData)
ScannerX_Pic2.Image = Image.FromStream(stmBLOBData)
End If
End Sub
Now I get the error Object reference not set to an instance of an object.

Answer 1

To save an image you could do something like this
Dim sql As String = "INSERT INTO Information VALUES(#name,#photo)"
Image Img = PictureBox1.BackgroundImage
Dim cmd As New SqlCommand(sql, con)
cmd.Parameters.AddWithValue("#name", TextBox1.Text)
Dim ms As New MemoryStream()
Img.Save(ms, Img.RawFormat)
Dim data As Byte() = ms.GetBuffer()
Dim p As New SqlParameter("#photo", SqlDbType.Image)
p.Value = data
cmd.Parameters.Add(p)
cmd.ExecuteNonQuery()
And to retrieve an image
cmd = New SqlCommand("select photo from Information where name='Rose'", con)
Dim imageData As Byte() = DirectCast(cmd.ExecuteScalar(), Byte())
If Not imageData Is Nothing Then
Using ms As New MemoryStream(imageData, 0, imageData.Length)
ms.Write(imageData, 0, imageData.Length)
PictureBox1.BackgroundImage = Image.FromStream(ms, True)
End Using
Also check out this article it's doing exactly what you are trying to achieve
http://www.codeproject.com/Articles/437937/Save-and-Retrieve-Image-from-a-SQL-Server-Database

Answer 2

The sql is selecting a column named "Finger":
"select Finger FROM Scanner"
But it's later trying to build an Image object from a column named "imagedate":
ds.Tables(0).Rows(c - 1)("imagedate")
It needs to use the same column name as the SQL result set:
ds.Tables(0).Rows(c - 1)("Finger")
There may be other problems as well, but that's what jumped out at me right away.