I have a user form containg a frame. During runtime, the user can add controls to this frame. Ultimately, the added controls can exceed the size of the frame. In this case I would like to increase the insideheight of the frame. So my vertical scrollbar does cover the whole area.
frm.ScrollHeight = .InsideHeight
How do I do this?
The .InsideHeight is not responsible for the scrollbar. However, the .ScrollHeight is. While adding new controls, this height must be increased.
When adding a new set of controls execute this:
Exchange 50 with the height of your control.
Dim scrHeight As Integer
With frm
scrHeight = .ScrollHeight
.ScrollHeight = scrHeight + 50
End With
Related
I am trying to display a line of pictures in my program. But I am having a problem, where it is only showing the first image in the imagelist and only showing one image-box.
Private Cards As New List(Of PictureBox)
Private Sub SetupCards()
For i As Integer = 0 To imglist1.Images.Count - 1
Dim PicCard As PictureBox = New PictureBox()
PicCard.Width = 100
PicCard.Height = 200
PicCard.Top = 50
PicCard.Left = 50
Me.Controls.Add(PicCard)
PicCard.Image = imglist1.Images(i)
Cards.Add(PicCard)
Next i
End Sub
You're placing the picture boxes on top of each other, which is why you only see the last card. You've got to set a different Left property for every picture box you add.
The solution is rather simple. Just add the picture box's width to Left, multiplied by the current index i.
PicCard.Left = 50 + PicCard.Width * i
Don't need to keep the imaging controls in your own list if you add them to a parent container control.
Use ListView or third-party controls, or use custom drawing code if you need to use ListBox (which wraps respective Windows control). See
C# Can I display images in a list box?
I have a form where I allow the user to generate multiple panels with some various contents in the panels by pressing an "add" button. Depending on what the user does in the panel, the panel grows and shrinks to fit the contents. Because of this change is size, I have created a sub that formats the panels on the form.
Private Sub formatPanels(frm As Form)
Dim count As Integer = 0
Dim startPoint As Point = New Point(12, 80)
Dim endPoint As Point = New Point(0, 0)
Dim maxY As Integer = 0
For Each pnl As Control In frm.Controls
If TypeOf pnl Is Panel Then
ReDim Preserve _arr_Panels(count)
_arr_Panels(count) = pnl
count += 1
pnl.Location = startPoint
startPoint.Y += pnl.Size.Height + 30
End If
Next
End Sub
So as you can see, we loop through every panel and the first always begins at the location (12,80) and then increments with the size of the panel and some spacing.
HERE IS THE ISSUE. This ONLY happens when i am SCROLLED DOWN the form. The panels spacing all of a sudden screws up and decides to put the first panel hundreds of pixels down the form. Is the location property based on what you're looking at? So if I were scrolled down the form location(0,0) would be the top left of the current view? There must be some weird property to location that I am not aware of.
Thanks
This behavior is not related to a panel, but to any control on a form with AutoScroll = True and Anchor including Top. (Note: if Anchor didn't also include Left I had some strange positioning on the first call of the function.
The solution is described here which is to use AutoScrollPosition. If you change your startPoint to this it will adjust for the scroll position.
Dim startPoint As Point = New Point(12, Me.AutoScrollPosition.Y + 80)
And the documentation for AutoScrollPosition states this:
When adding controls programmatically to a form, use the AutoScrollPosition property to position the control either inside or outside of the current viewable scroll area.
Label text to grow on left side while making the right side fixed in vb.net.Image is attached for better understanding
Label text to grow on left side:-
What you need is to set your text label to be right-justified. Showing the part of your code related to creating and populating the label (the one displaying the total amount) will help.
You could set Autosize = False and choose TextAllign = *right. The actual label wouldn't grow, so you'd need to set a 'sufficient' width.
Alternative is to do it via code:
'find the current right alignment position
Dim rightAlign As Integer = Label1.Left + Label1.Width
'set the text (assumes AutoSize is set to True)
Label1.Text = value
'adjust position so the right hand point is in the same position as before
Label1.Left = rightAlign - Label1.Width
Depending on how your form is laid out, you can dock the label to the right and set:
Label.Dock = DockStyle.Right
Label.AutoSize = True
This will make your label expand to the left. Docking to the right will put your label at the top of the form unless you have an appropriate layout.
I've got a WinForms Panel control which holds a large number of child controls. Each child is left docked, causing the horizontal width of the contents to grow. The containing Panel has its AutoScroll property set so that you can get to all the contents.
I'm running into a problem when the total width of the contents gets too large. Once you've hit this maximum width, additional content elements are placed on top of existing contents instead of being placed to the right. But, if I resize the Panel after it has done its initial layout, it corrects itself by expanding its logical width and placing each content element in the correct location. How do I get it to layout correctly before the user resizes the window?
Here's a simple example:
Form1.vb
Public Class Form1
Protected Overrides Sub OnLoad(e As EventArgs)
MyBase.OnLoad(e)
For i As Integer = 1 To 200
Dim gb As New GroupBox
gb.Text = "Box " & i.ToString
gb.Width = 250
gb.Dock = DockStyle.Left
Panel1.Controls.Add(gb)
gb.BringToFront()
Next
End Sub
End Class
Form1.Designer.vb
Partial Class Form1
Inherits System.Windows.Forms.Form
Private Sub InitializeComponent()
Me.Panel1 = New System.Windows.Forms.Panel()
Me.SuspendLayout()
'
'Panel1
'
Me.Panel1.AutoScroll = True
Me.Panel1.Dock = System.Windows.Forms.DockStyle.Fill
Me.Panel1.Location = New System.Drawing.Point(0, 0)
Me.Panel1.Name = "Panel1"
Me.Panel1.Size = New System.Drawing.Size(284, 262)
Me.Panel1.TabIndex = 0
'
'Form1
'
Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
Me.ClientSize = New System.Drawing.Size(284, 262)
Me.Controls.Add(Me.Panel1)
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
Friend WithEvents Panel1 As System.Windows.Forms.Panel
End Class
This is what the window looks like when it first comes up, scrolled nearly to the end so you can see the problem area. Notice that Box 183 to 199 are missing because they are placed on top of each other. This is not right.
This is what the window looks like after you manually resize it, scrolled nearly to the end. The panel fixed itself in response to the resize; the total logical width of the panel was automatically extended enough to hold all the contents. This is what I want it to look like when it first comes up.
I've tried manually setting the location of each box, and I've tried calling PerformLayout() and several other functions. Nothing seems to work. So far I haven't found the magic combination to get the good layout. Does anyone know how to fix this?
Edit:
Here's a screenshot that might make the issue more obvious. I adjusted the box widths and the number of boxes to show the problem better. See how the last box overlaps box 656? Every box from 657 to 700 has the same incorrect location. Turning off docking and setting the location myself doesn't help.
Looks like a bug with the scrolling information. If you call PerformLayout when the Panel is scrolled all the way to the right, it correctly places the controls in the proper place. That requires some code in the OnShown method:
Protected Overrides Sub OnLoad(e As EventArgs)
MyBase.OnLoad(e)
Panel1.AutoScroll = True
Panel1.SuspendLayout()
For i As Integer = 1 To 200
Dim gb As New GroupBox
gb.Text = "Box " & i.ToString
gb.Width = 250
gb.Dock = DockStyle.Left
Panel1.Controls.Add(gb)
gb.BringToFront()
Next
Panel1.ResumeLayout(False)
End Sub
Protected Overrides Sub OnShown(e As EventArgs)
MyBase.OnShown(e)
Panel1.AutoScrollPosition = New Point(Panel1.HorizontalScroll.Maximum - _
Panel1.HorizontalScroll.LargeChange, 0)
Panel1.PerformLayout()
Panel1.AutoScrollPosition = Point.Empty
End Sub
Of course, having over 200 container controls on the form is never recommended.
AutoScroll is not AutoPositionMyChildren. From MSDN:
When adding controls programmatically to a form, use the AutoScrollPosition property to position the control either inside or outside of the current viewable scroll area.
If you looped thru the controls, to print their location, you's see at some point (probably around 130) that Location.Y becomes fixed at 32767 probably some default unscrolled max. This is also the point they start stacking because they in fact have the same initial location. Some of the code you have makes up for that but it isnt quite right. Once you scroll it, the panel fixes the coords on the child controls.
First, I would suggest that you set Panel1.AutoScrollMinSize to something like {480, 0} so that the HScroll bar appears at design time; this allows you to calc a good height for the boxes which wont cause a VScroll as you add controls.
Dim gb As GroupBox
' only 150 because problem is when (i * width) > 32k
For i As Integer = 0 To 150
gb = New GroupBox
gb.Name = i.ToString ' added
gb.Text = "Box " & i.ToString
gb.Width = 250
' no docking so set the height
gb.Height = Panel1.Bounds.Height - 30 ' trying to avoid the VSCroll
' set location explicitly
gb.Location = NewCtlLocation(Panel1.Controls.Count,
Panel1.AutoScrollPosition.X)
' Dock and Anchor mess up the AutoScroll
'gb.Dock = DockStyle.Left
Panel1.Controls.Add(gb)
' allow panel to update its scroll positions
Panel1.ScrollControlIntoView(gb)
' not needed; seems to offset something with Dock
' changing ZOrder may not always be desirable
'gb.BringToFront()
' debug illumination
Console.WriteLine("{0} {1} {2}", i.ToString,
Panel1.AutoScrollPosition.X.ToString,
gb.Location.X.ToString)
Next
'Go back to start
Panel1.ScrollControlIntoView(Panel1.Controls("0"))
Location helper so you can tweak gutters or margins (dock replacement):
Friend Function NewCtlLocation(ByVal n As Integer,
ByVal ScrollPosX As Integer) As Point
Const TopMargin As Integer = 5
Const LeftMargin As Integer = 5
Return New Point((n * 250) + ScrollPosX, 0)
End Function
Notes:
I have a vertical scroller which repeatedly adds up to 120 user controls which works well but it does not need/use ScrollControlIntoView and they never stack up like yours do. I suspect maybe because they are smaller. There is also at least a second or two before the next one can be added, which may matter. But, good to know.
It might be possible to use the ControlAdded event of the panel to do something, but it would likely amount to ScrollControlIntoView. Doing it once at the end only doesnt work, so using it as they are added is allowing something to get updated as you go.
With the right fiddling, you might be able to get Dock to work, but I suspect it may be part of the problem such as Height and Left set this way dont update the panel's internal scroll map.
Your boxes actually look narrower than 250 - is autosize on?
Suspend/Resume Layout hurt rather than help - they prevent the control from doing anything about the virtual area being populated. It should happen fast enough that no one will see anything. Results:
Works on My SystemTM
I'm writing a simple app that's going to have a tiny form sitting in one corner of the screen, updating itself.
I'd really love for that form to be transparent and to have the transparency be user-configurable.
Is there any easy way to achieve this?
You could try using the Opacity property of the Form. Here's the relevant snippet from the MSDN page:
private Sub CreateMyOpaqueForm()
' Create a new form.
Dim form2 As New Form()
' Set the text displayed in the caption.
form2.Text = "My Form"
' Set the opacity to 75%.
form2.Opacity = 0.75
' Size the form to be 300 pixels in height and width.
form2.Size = New Size(300, 300)
' Display the form in the center of the screen.
form2.StartPosition = FormStartPosition.CenterScreen
' Display the form as a modal dialog box.
form2.ShowDialog()
End Sub
Set Form.Opacity = 0.0 on page load
I set something like what your talking about on an app about a year ago. Using a While loop with a small Sleep you can setup a nice fading effect.
I don't know exactly what you mean by transparent, but if you use WPF you can set AllowTransparency = True on your form and then remove the form's style/border and then set the background to a color that has a zero alpha channel. Then, you can draw on the form all you want and the background will be see-through and the other stuff will be fully visible. Additionally, you could set the background to a low-opacity layer so you can half see through the form.
You can set the Form.Opacity property. It should do what you want.