[RESOLVED] Draggable Form

[Pixy]

I'm trying to make a borderless form draggable. I'm using the following code:

Imports System.Runtime.InteropServices

Public Class FormDrag
    Public Const WM_NCLBUTTONDOWN As Integer = &HA1
    Public Const HT_CAPTION As Integer = &H2
    <DllImport("user32.dll")>
    Public Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer

    End Function
    <DllImport("user32.dll")>
    Public Shared Function ReleaseCapture() As Boolean

    End Function
End Class

    ' Make Form1 draggable
    Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)
        FormDrag.ReleaseCapture()
        FormDrag.SendMessage(Me.Handle, FormDrag.WM_NCLBUTTONDOWN, FormDrag.HT_CAPTION, 0)
    End Sub

Not working, help please.

[.paul.]

Here's how...

Public Class Form1

    Const WM_NCLBUTTONDOWN As Integer = &HA1
    Const HT_CAPTION As Integer = &H2

    Protected Overrides Sub OnMouseDown(ByVal e As System.Windows.Forms.MouseEventArgs)
        MyBase.OnMouseDown(e)

        Me.Capture = False
        Dim msg As Message = _
            Message.Create(Me.Handle, WM_NCLBUTTONDOWN, _
                    New IntPtr(HT_CAPTION), IntPtr.Zero)
        Me.DefWndProc(msg)

    End Sub

End Class

[Pixy]

Is this virus?

[.paul.]

To start, No it's not a virus if you're referring to the code i gave you. Please post text for code snippets and text for error messages. Your image is barely readable...

[.paul.]

Don't take my word for it... Ask some experienced members. I'll ask a moderator to check it.

[Pixy]

To start, No it's not a virus if you're referring to the code i gave you. Please post text for code snippets and text for error messages. Your image is barely readable...

Avira thinks it's a virus. Is there any more legit way to do this?

[.paul.]

That is a legit way. If you want a more legit answer, get rid of Avira and get a legit antivirus program.
It really shouldn't cause a virus scare. Are you sure your other code is ok?

[Pixy]

That is a legit way. If you want a more legit answer, get rid of Avira and get a legit antivirus program.
It really shouldn't cause a virus scare. Are you sure your other code is ok?

Bad avira
Yes, rest of the code is button click event.

[Pixy]

Other than the antivirus issue it works. Resolved.

[passel]

As an alternative to using an API, I've used code similar to this since VB1 days.

  Private Sub Form1_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
    Static lpos As Point
    If e.Button = Windows.Forms.MouseButtons.Left Then
      Me.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
    Else
      lpos = e.Location
    End If
  End Sub

[Pixy]

As an alternative to using an API, I've used code similar to this since VB1 days.

  Private Sub Form1_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
    Static lpos As Point
    If e.Button = Windows.Forms.MouseButtons.Left Then
      Me.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
    Else
      lpos = e.Location
    End If
  End Sub

Nice, will check it out.

[Shaggy Hiker]

Those screen shots are barely legible. It sure looks like the screen shot was the code that .Paul. posted, though, and there's no way that's a virus. I'm amazed that the anti-virus even saw it as anything. However, it did suggest that it was a heuristic scan, in which case it was looking for patters that it saw as being like a virus. I suppose, that if you were being overly broad in your definition, then creating and sending a message to a message queue is something that a virus might do. Of course, at that point, you are also ruling out LOADS of legitimate programs, as well.

I recently ran into a case where a program I wrote was flagged by an overly aggressive heuristics engine simply because it started up...then immediately spun off a thread that called out to a URL. Of course, that was what it was supposed to do, since it had to get information from the API at the URL to allow the user to decide what to do next, but it's certainly something a trojan would also do, as well.

Anti-virus is a constantly moving field. I don't know what companies are better and which are worse, and anything I said today would be wrong tomorrow, anyways. The result is that some are a bit overly/incorrectly aggressive. That's all this seems to be.

[Pixy]

Those screen shots are barely legible. It sure looks like the screen shot was the code that .Paul. posted, though, and there's no way that's a virus. I'm amazed that the anti-virus even saw it as anything. However, it did suggest that it was a heuristic scan, in which case it was looking for patters that it saw as being like a virus. I suppose, that if you were being overly broad in your definition, then creating and sending a message to a message queue is something that a virus might do. Of course, at that point, you are also ruling out LOADS of legitimate programs, as well.

I recently ran into a case where a program I wrote was flagged by an overly aggressive heuristics engine simply because it started up...then immediately spun off a thread that called out to a URL. Of course, that was what it was supposed to do, since it had to get information from the API at the URL to allow the user to decide what to do next, but it's certainly something a trojan would also do, as well.

Anti-virus is a constantly moving field. I don't know what companies are better and which are worse, and anything I said today would be wrong tomorrow, anyways. The result is that some are a bit overly/incorrectly aggressive. That's all this seems to be.

Very true. Especially Avira is really touchy and thinks that everything is a virus. I had the same issue with similar code. It's probably because the mouse behavior in relation to the windows form was modified. For example there's an old virus that changes right click with left click

As an alternative to using an API, I've used code similar to this since VB1 days.

  Private Sub Form1_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
    Static lpos As Point
    If e.Button = Windows.Forms.MouseButtons.Left Then
      Me.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
    Else
      lpos = e.Location
    End If
  End Sub

passel, how can I do this for a picturebox? I used:

Private Sub PictureBox4_Click(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles PictureBox4.Click
        Static lpos As Point
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Me.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
        Else
            lpos = e.Location
        End If
    End Sub

but the window moves after 10+ seconds and many tries while lagging.

[passel]

It wouldn't be the click event, it would be the same event, i.e. MouseMove.

[passel]

Also, "Me.Location", Me refers to the form, so you need to change Me to the object you want to move, like Picturebox1.
But, the "Sender" parameter refers to the object that the event is associated with, so you could cast Sender to a Picturebox type or Form type.
If you want to have a single Sub that can handle most any control, then cast Sender to Control.
Here's a quick example that handles the form and picturebox1 on the form.

  Private Sub Control_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) _
              Handles PictureBox1.MouseMove, Me.MouseMove

    Dim pb As Control = DirectCast(sender, Control)
    Static lpos As Point
    If e.Button = Windows.Forms.MouseButtons.Left Then
      pb.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
    Else
      lpos = e.Location
    End If
  End Sub

[Pixy]

Also, "Me.Location", Me refers to the form, so you need to change Me to the object you want to move, like Picturebox1.
But, the "Sender" parameter refers to the object that the event is associated with, so you could cast Sender to a Picturebox type or Form type.
If you want to have a single Sub that can handle most any control, then cast Sender to Control.
Here's a quick example that handles the form and picturebox1 on the form.

  Private Sub Control_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) _
              Handles PictureBox1.MouseMove, Me.MouseMove

    Dim pb As Control = DirectCast(sender, Control)
    Static lpos As Point
    If e.Button = Windows.Forms.MouseButtons.Left Then
      pb.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
    Else
      lpos = e.Location
    End If
  End Sub

Interesting. Using this the form moves if you drag your mouse inside the form and when you drag the mouse inside the picturebox the picturebox alone moves. What I want to is to imitate the dragging effect of the top bar where the title is in normal forms. My form being borderless does not have the top bar so I use a picturebox to imitate one. So if the mouse is dragged inside the picturebox the form as a whole should move. If the mouse is dragged outside of the picturebox nothing should happen. Right now I'm trying to figure this out, if you have something in mind I would appreciate it.

[.paul.]

Private Sub Control_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) _
              Handles PictureBox1.MouseMove

    Static lpos As Point
    If e.Button = Windows.Forms.MouseButtons.Left Then
      me.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
    Else
      lpos = e.Location
    End If
End Sub

[passel]

Interesting. Using this the form moves if you drag your mouse inside the form and when you drag the mouse inside the picturebox the picturebox alone moves. What I want to is to imitate the dragging effect of the top bar where the title is in normal forms. ...

Well, if you had mentioned that then I might not have posted post #15. The answer in post #14 would have done what you wanted, which is .paul. shows explicitly.

Hopefully, you will want to understand what the code is doing and why, rather than just pasting posted code blindly without understanding what it is doing. Many of the responses to questions here can be an example that may have to be tweaked to fit your specific requirement.
In this case, that wasn't the case, you just needed to understand that the code is keeping track of where the mouse is in the mouseMove event. If the mouse button is down and the mouse moved, the amount that it moved is added to the location of the form, which essentially puts the point where the mouse was click back under the mouse's current position.

[Pixy]

Private Sub Control_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) _
              Handles PictureBox1.MouseMove

    Static lpos As Point
    If e.Button = Windows.Forms.MouseButtons.Left Then
      me.Location += New Size(e.X - lpos.X, e.Y - lpos.Y)
    Else
      lpos = e.Location
    End If
End Sub

Ah Me.MouseMove was the problem. I'm not familiar with Me. at all. Thanks a bunch paul!

[.paul.]

You don't even need the picturebox. You can just check if the mousemove (drag) started in a specific part of the form (i.e. In your fake titlebar area)

[.paul.]

Ah Me.MouseMove was the problem. I'm not familiar with Me. at all. Thanks a bunch paul!

In the context it is used there, Me refers to the Form

Edit: The way passel showed you, that moved either the whole form when dragging in the form, or moved the picturebox within the form when dragging in the picturebox, was because passel was handling the mousemove event for both the form and the picturebox, and setting the location for the sender object, which was either the form or the picturebox...

[Pixy]

In the context it is used there, Me refers to the Form

Edit: The way passel showed you, that moved either the whole form when dragging in the form, or moved the picturebox within the form when dragging in the picturebox, was because passel was handling the mousemove event for both the form and the picturebox, and setting the location for the sender object, which was either the form or the picturebox...

Ahh, now I understand.