LessThanDot

Allthough the MongoDB documentation says that it support binary data, I don’t think the .Net driver really does.

Document-oriented storage (the power and flexibility of JSON-like data schemas)

Dynamic queries

Full index support, including secondary indexes, inner-objects, embedded arrays, geospatial

Query profiling

Fast, in-place updates

Efficient storage of binary data large objects (e.g. photos and videos)

Replication and fail-over support

Auto-sharding for cloud-level scalability

MapReduce for complex aggregation

Commercial Support, Training, and Consulting

Beacuse when I try to add an image as property the whole thing blows up.

But we could just treat it as json and be done with it.

json is pretty limited to these things.

JSON’s basic types are:

Number (integer or real)

String (double-quoted Unicode with backslash escaping)

Boolean (true or false)

Array (an ordered sequence of values, comma-separated and enclosed in square brackets)

Object (a collection of key:value pairs, comma-separated and enclosed in curly braces)

null

That would mean that we encode our image as Base64 string and then read it back in.

So I changed my Person class to this.

```vbnet Public Class Person Private _Name As String Private _FirstName As String Private _Image As System.Drawing.Bitmap

    Public Sub New()
        _Name = ""
    End Sub

    Public Property Name() As String
        Get
            Return _Name
        End Get
        Set(ByVal value As String)
            _Name = value
        End Set
    End Property

    Public Property FirstName() As String
        Get
            Return _FirstName
        End Get
        Set(ByVal value As String)
            _FirstName = value
        End Set
    End Property

    Public Function GetImage() As System.Drawing.Image
        Return _Image
    End Function

    Public Sub SetImage(ByVal Image As System.Drawing.Image)
        _Image = Image
    End Sub

    Public Property Image() As String
        Get
            Dim base64string As String = ""
            Try
                Dim ms = New System.IO.MemoryStream()
                _Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg)
                Dim imageBytes = ms.ToArray()
                base64string = Convert.ToBase64String(imageBytes)
            Catch ex As Exception

            End Try
            Return base64String
        End Get
        Set(ByVal value As String)
            Try
                Dim imageBytes = Convert.FromBase64String(value)
                Dim ms = New System.IO.MemoryStream(imageBytes, 0, imageBytes.Length)
                ms.Write(imageBytes, 0, imageBytes.Length)
                _Image = System.Drawing.Image.FromStream(ms, True)
            Catch ex As Exception
                _Image = Nothing
            End Try
       End Set
    End Property
End Class```

And now my code just works.

vbnet Sub Main() Dim mongo As New Mongo mongo.Connect() Dim db = mongo.GetDatabase("person") Dim persons = db.GetCollection("persons") Console.WriteLine("You have " & persons.Count & " persons in your database") Dim person As New Person person.Name = "name1" person.FirstName = "firstname1" person.SetImage(System.Drawing.Image.FromFile("C:UserschristiaanPicturesBackgroundskoala.jpg")) persons.Insert(person.ToDocument) Dim person2 As New Person person2.Name = "name2" person2.FirstName = "firstname2" persons.Insert(person2.ToDocument) Console.WriteLine("You have " & persons.Count & " persons in your database") For Each personfound In persons.FindAll.Documents Console.WriteLine("Found person: " & personfound("_id").ToString & " " & personfound("Name") & " " & personfound("FirstName")) Next For Each personfound In persons.FindAll.Documents Dim person1 = personfound.ToClass(Of Person)() Console.WriteLine("Found person: " & person1.Name & " " & person1.FirstName) Next persons.Delete(New Document) Console.WriteLine("You have " & persons.Count & " persons in your database") Console.ReadLine() End Sub But of course that isn’t showing us the Image is actualy usable.

So I did this instead.

```vbnet Imports MongoDB.Driver

Public Class Form1

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim mongo As New Mongo
    mongo.Connect()
    Dim db = mongo.GetDatabase("person")
    Dim persons = db.GetCollection("persons")
    Dim person As New Person
    person.Name = "name1"
    person.FirstName = "firstname1"
    person.SetImage(System.Drawing.Image.FromFile("C:UserschristiaanPicturesBackgroundskoala.jpg"))
    persons.Insert(person.ToDocument)
    For Each personfound In persons.FindAll.Documents
        Dim person1 = personfound.ToClass(Of Person)()
        PictureBox1.Image = person1.GetImage
    Next
    persons.Delete(New Document)
End Sub

End Class``` And hey presto.

MongoDB persisting System.Drawing.Image

About Christiaan Baes (chrissie1)