VB.NET - VB 2010 code for saving a picturebox, with a drawing on it.

'I  wanted a resultfile with an image ,wherupon a red line was painted,

'but what I got was only the image of the picturebox,

'without te red Line.

'the code-line:

'myPictureBox.Image.Save("c:\Temp\MyPicture.jpg", ImageFormat.Jpeg)

'is wrong,

'What is the right  code for this?

 

Imports System.Drawing.Imaging

Public Class Form1

   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    myPictureBox.BackColor = Color.Yellow

    Dim file_name = "C:\TEMP\test.jpg"

    myPictureBox.Image = Image.FromFile(file_name)

  End Sub

  Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint

    Dim redPen As Pen = New Pen(Color.Red, 20)

    Dim point1 As Point = New Point(0, 0)

    Dim point2 As Point = New Point(130, 150)

    Dim G As Graphics

    G = myPictureBox.CreateGraphics

    G.DrawLine(redPen, point1, point2)

  End Sub

  Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

    myPictureBox.Image.Save("c:\Temp\MyPicture.jpg", ImageFormat.Jpeg)

    picDownloaded.Image = Image.FromFile("c:\Temp\MyPicture.jpg")

  End Sub

End Class

I  wanted a resultfile with an image ,wherupon a red line was painted,

but what I got was only the image of the picturebox,

without te red Line.

the code-line:

myPictureBox.Image.Save("c:\Temp\MyPicture.jpg", ImageFormat.Jpeg)

is wrong,

What is the right  code for this?

graphics drawn on a picturebox that way aren't persistent + aren't drawn to the picturebox image property. you need to draw directly to the underlying bitmap, either with fixed coordinates like you're using, or taking coordinates from the picturebox's mousedown + or mousemove events.

here's an example:

vb Code:

    Public Class Form1
      Dim img As Bitmap
      Dim gr As Graphics
      Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        img = New Bitmap("dummy.jpg")
        gr = Graphics.FromImage(img)
        PictureBox1.Image = img
      End Sub
      Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim pen1 As New System.Drawing.Pen(System.Drawing.Color.Green, 4)
        gr.DrawEllipse(pen1, 70, 10, 100, 150)
        PictureBox1.Image = img
        img.Save("dummy.jpg", Drawing.Imaging.ImageFormat.Jpeg)
      End Sub
    End Class

hi,

Try below code:

Thank you very much.

I'm glad to find a solution for saving such pictureboxes.
I searched a lot for this solution.
 
I will use this solution many times, I'm sure.

Geert Vullings

Welcome!