Solved

Drawing a Bounding Box rectangle in vb.net 2005

Posted on 2009-05-14
4
1,523 Views
Last Modified: 2013-11-27
Hello,

I never thought I'd actually be writing on how to do this, but I am having nothing but trouble getting this to work.

I have a picture on the screen.  I want to give the user the ability to crop the picture, so I have a crop button on the toolbar.  When cropping starts, I want the user to be able to click and drag around the area that they want to keep within the picture.  I would like to draw a rectangle AS they move the mouse.

What I'm running into is I can do the draw rectangle, but as the mouse moves, another rectangle is created and another, etc. so I end up with a series of rectangles rather than one when I'm all done.

In vb6 world, I used a "shape" to accomplish this and just kept moving the bottom right point of the shape.  I just don't know how to do this in vb.net 2005

Thanks so much
Gary H.
0
Comment
Question by:garyhoffmann
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
4 Comments
 
LVL 86

Accepted Solution

by:
Mike Tomlinson earned 250 total points
ID: 24389440
Bare bones "rubberbanding" example in VB.Net 2005:
Public Class Form1
 
    Private RC As Rectangle
    Private screenPtA, screenPtB As Point
 
    Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Dim pb As PictureBox = CType(sender, PictureBox)
            Cursor.Clip = pb.RectangleToScreen(pb.ClientRectangle)
            screenPtA = Cursor.Position
            screenPtB = screenPtA
            RC = NormalizedRC(screenPtA, screenPtB)
            ControlPaint.DrawReversibleFrame(RC, Color.Black, FrameStyle.Dashed)
        End If
    End Sub
 
    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            ControlPaint.DrawReversibleFrame(RC, Color.Black, FrameStyle.Dashed)
            screenPtB = Cursor.Position
            RC = NormalizedRC(screenPtA, screenPtB)
            ControlPaint.DrawReversibleFrame(RC, Color.Black, FrameStyle.Dashed)
        End If
    End Sub
 
    Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Cursor.Clip = Nothing
            Dim pb As PictureBox = CType(sender, PictureBox)
            RC = pb.RectangleToClient(RC)
 
            MessageBox.Show(RC.ToString, "Client Crop Rectangle")
        End If
    End Sub
 
    Public Function NormalizedRC(ByVal ptA As Point, ByVal ptB As Point) As Rectangle
        Return New Rectangle(Math.Min(ptA.X, ptB.X), Math.Min(ptA.Y, ptB.Y), Math.Abs(ptA.X - ptB.X), Math.Abs(ptA.Y - ptB.Y))
    End Function
 
End Class

Open in new window

0
 

Author Comment

by:garyhoffmann
ID: 24394485
Idle Mind - this is great.  Thank you.  But... (and there's always a but....)

What if the user realizes they started in the wrong place and wants to start over?  How do I remove the rectangle that's been drawn?

Thank you.
Gary.
0
 

Author Comment

by:garyhoffmann
ID: 24394656
Idle Mind,

Never mind - I found my own answer based on your code.  Thanks again.

Gary
0
 
LVL 86

Expert Comment

by:Mike Tomlinson
ID: 24396049
To clear the PB just issue a Refresh() and any existing bounding box will be cleared:

    PictureBox1.Refresh()
0

Featured Post

Enroll in May's Course of the Month

May’s Course of the Month is now available! Experts Exchange’s Premium Members and Team Accounts have access to a complimentary course each month as part of their membership—an extra way to increase training and boost professional development.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

For most people, the WrapPanel seems like a magic when they switch from WinForms to WPF. Most of us will think that the code that is used to write a control like that would be difficult. However, most of the work is done by the WPF engine, and the W…
Whether you've completed a degree in computer sciences or you're a self-taught programmer, writing your first lines of code in the real world is always a challenge. Here are some of the most common pitfalls for new programmers.
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question