showimagevb.aspx.vb

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Imports System.IO
Imports System.Data.OleDb

Namespace Telerik.UploadExamplesVBNet.PhotoGallery
    Public Class ShowImageVB
        Inherits System.Web.UI.Page

#Region " Web Form Designer Generated Code "

        'This call is required by the Web Form Designer.
        <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

        End Sub

        'NOTE: The following placeholder declaration is required by the Web Form Designer.
        'Do not delete or move it.
        Private designerPlaceholderDeclaration As System.Object

        Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
            'CODEGEN: This method call is required by the Web Form Designer
            'Do not modify it using the code editor.
            InitializeComponent()
        End Sub

#End Region

        Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
            'Get the file information from the database
            Dim conn As OleDbConnection = New OleDbConnection(DefaultVB.GetConnectionString(Request))
            conn.Open()
            If Request.QueryString("imgid") Is Nothing Then
                WriteImage(GetEmptyImage(), "NoImage")
                Return
            End If

            Dim query As String = "SELECT {0}, [Name] FROM Images WHERE ImageID = ?"

            'Check if to get the thumbnail of a file, or to get the full file
            If (Not Request.QueryString("type") Is Nothing) And Request.QueryString("type") = "thumb" Then
                query = String.Format(query, "Thumbnail")
            Else
                query = String.Format(query, "[Image]")
            End If

            'Get the image and display it
            Dim command As OleDbCommand = New OleDbCommand(query, conn)
            command.Parameters.Add("@ImageID", Integer.Parse(Request.QueryString("imgid")))
            Dim reader As OleDbDataReader = command.ExecuteReader()
            If reader.Read() Then
                WriteImage(CType(reader(0), Byte()), reader(1).ToString())
                reader.Close()
            Else
                'There was not such an image, so display the no_image image
                WriteImage(GetEmptyImage(), "NoImage")
            End If

        End Sub
        Private Sub WriteImage(ByVal image As Byte(), ByVal fileName As String)
            Response.Buffer = True
            Response.Clear()
            Response.ContentType = "image/gif"
            Response.AddHeader("content-disposition", "inline; filename=" + fileName)
            Response.BinaryWrite(image)
            Response.Flush()
            Response.End()
        End Sub
        Private Function GetEmptyImage() As Byte()
            Dim height As Integer = DefaultVB.MAX_THUMBNAIL_HEIGHT
            Dim width As Integer = DefaultVB.MAX_THUMBNAIL_WIDTH
            Dim empty As Bitmap = New Bitmap(width, height)
            Dim ms As MemoryStream = New MemoryStream
            empty.Save(ms, System.Drawing.Imaging.ImageFormat.Gif)
            Return ms.ToArray()
        End Function



    End Class

End Namespace