About Drawing a moveable rectangle of an uploaded image in Visual Basic - vb.net

Question

I've been working on a moveable rectangle to compute the ROI of an Image in VB 2010, Since i'm new to VB, I've been able to create a rectangle, But it doesnot appear on my uploaded image. It appears but not on the image. By my listed code below
1. How do I get the rectangle to display on the image.
2. How do get the rectangle to become moveable through out the image. I will be grateful. thanks.
Private Sub ROIToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles ROIToolStripMenuItem.Click
Dim G As Graphics
G = PictureBox1.CreateGraphics
G.SmoothingMode = Drawing.Drawing2D.SmoothingMode.AntiAlias
G.FillRectangle(Brushes.Silver, ClientRectangle)
Dim P As Point
Dim Box As Rectangle
P.X = 1
P.Y = 1
Dim S As Size
S.Width = 100
S.Height = 20
Box = New Rectangle(P, S)
G.DrawRectangle(Pens.Red, Box)

Answer 1

Try the below code
Dim G As Graphics
Dim uploadedBmp1, backgroundBmp1 As Bitmap
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
uploadedBmp1 = New Bitmap("C:\Windows\winnt.bmp")
backgroundBmp1 = New Bitmap(uploadedBmp1.Width, uploadedBmp1.Height)
G = Graphics.FromImage(backgroundBmp1)
PictureBox1.Image = backgroundBmp1
End Sub
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
DrawRectangleOnImage(New Point(0, 0), New Size(100, 50))
End Sub
Private Sub DrawRectangleOnImage(ByVal point1 As Point, ByVal size1 As Size)
G.Clear(Color.White)
G.DrawImage(uploadedBmp1, 0, 0, uploadedBmp1.Width, uploadedBmp1.Height)
Dim rectangle1 As New Rectangle(point1, size1)
G.DrawRectangle(Pens.Red, rectangle1)
PictureBox1.Invalidate()
End Sub
to make a moving rectangle, just call the DrawRectangleOnImage sub with the parameters that you want. It will automatically clear the previous snapshot and draw everything again.