I have migrated a userControl from vb6 to vb.net, and i have problem with it's transparency.
in vb6, the property backstyle was used to make the control transparent, but in vb.net, i can't find it.
is there any equivalent for this property?
After some searches on the internet I found this pearl:
Protected Overrides ReadOnly Property CreateParams() As CreateParams
Get
' Make background transparent
Dim cp As CreateParams = MyBase.CreateParams
cp.ExStyle = cp.ExStyle Or &H20
Return cp
End Get
End Property
Protected Overrides Sub OnPaintBackground(e As PaintEventArgs)
'' call MyBase.OnPaintBackground(e) only if the backColor is not Color.Transparent
If Me.BackColor <> Color.Transparent Then
MyBase.OnPaintBackground(e)
End If
End Sub
I've tested it and it seems to be working fine.
Related
I found the following code which cancels the flickering in a WinForms application:
Protected Overrides ReadOnly Property CreateParams() As CreateParams
Get
Dim cp As CreateParams = MyBase.CreateParams
cp.ExStyle = cp.ExStyle Or &H2000000
Return cp
End Get
End Property 'CreateParams
The issue comes when "minimizing and maximizing the form, all controls are invisible. Removing &H2000000 fix the problem, but the controls start to flicker" like it says in this comment on this question.
There's any update or way to solve this?
I want clean the PictureBox image, so I make this code: TransparentPictureBox.Image = Nothing, the image don't disappear and I obtain all new image overlapping to the previous. How can I fix this?
I stay using a custom control, this is the class:
Public Class TransparentPictureBox
Inherits PictureBox
Public Sub New()
Me.SetStyle(ControlStyles.Opaque, True)
Me.SetStyle(ControlStyles.OptimizedDoubleBuffer, False)
End Sub
Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
Get
Dim cp As CreateParams = MyBase.CreateParams
cp.ExStyle = cp.ExStyle Or &H20 ' Turn on WS_EX_TRANSPARENT
Return cp
End Get
End Property
End Class
The control is working exactly as you designed it.
With the ControlStyles.Opaque option set to True, it does not draw its background:
If true, the control is drawn opaque and the background is not painted.
When you set the Image property to Nothing, you're expecting it to be emptied.
How does a PictureBox draw itself though? It first draws the background color, then it draws the image on top of that. Since you've disabled background painting, though, the background doesn't get drawn and the previous image doesn't get erased.
Why do you have that option set? Remove it if that is not the behavior you're looking for.
Just write this although this not optimal solution but it will work
picturebox1.imagelocation = ""
I am trying to set the background color of textbox to transparent, to blend with my backcolor of my form.
I have tried the following below.
TextBox1.BackColor = Color.Transparent 'This doesn't work it stays white'
Is there something I am missing?
When I set TextBox.BackColor to Color.Transparent, it throws System.ArgumentException. I got this message :
Unvalid property value, The control does not support transparent colors background.
Hope am not late to the party, but this actually works for me. First create a class for the panel as below
Partial Public Class iPanel
Inherits Panel
Public Sub New()
SetStyle(ControlStyles.SupportsTransparentBackColor Or ControlStyles.OptimizedDoubleBuffer Or ControlStyles.AllPaintingInWmPaint Or ControlStyles.ResizeRedraw Or ControlStyles.UserPaint, True)
BackColor = Color.Transparent
End Sub
End Class
Then create a RichTextBox (Instead of a Textbox) as below
Protected Overrides ReadOnly Property CreateParams() As CreateParams
Get
Dim CP As CreateParams = MyBase.CreateParams
CP.ExStyle = CP.ExStyle Or &H20
Return CP
End Get
End Property
Now compile the code and add the iRichTextBox inside the panel. Works for me
Private Sub TextBox1_Paint(sender As Object, e As PaintEventArgs) Handles TextBox1.Paint
TextBox1.ForeColor = Color.White
TextBox1.BackColor = Color.Transparent
End Sub
Instead of doing the first one, You can try this. Just put your code in Form Load
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
TextBox1.BackColor = color.(color of your Choice, same color of your background)
TextBox1.ForeColor = color.White
End Sub
As simple as that, it works for me
As far as I know textbox does not support transparent color property. But if you set the back color of the textbox to the same color as of its background component, still it can be considered as transparent.
How to do that - You can get the color name of the background component(in your case it is the form) and pass that name to the component which you want to be transparent.
Dim lname As String = Me.BackColor.ToString
Dim name As String = lname.Substring(7, lname.Length - 8)
txtbox1.BackColor = System.Drawing.Color.FromName(name)
Explanation -
The first line in the code gets you the name of the color, but there's a rub, it gets the name something like this - Color [Dark Orange] and we need only the name of the color i.e Dark Orange.
Thus the second line is to get the exact color name by removing this - Color [] part
And the last line to set that color same as of the background component color.
Hope it works, still have problem let me know...
I am working on vb6.net winforms. I have created two buttons named yes and no Respectively.I have disabled the close button use the following code shown below:
Private Const CP_NOCLOSE_BUTTON As Integer = &H200
Protected Overrides ReadOnly Property CreateParams() As CreateParams
Get
Dim myCp As CreateParams = MyBase.CreateParams
myCp.ClassStyle = myCp.ClassStyle Or CP_NOCLOSE_BUTTON
Return myCp
End Get
End Property
My question is I want to re - enable it when the user completes his requirement by clicking on the yes button.
There is no need to Override the CreateParams. You could easily turn off/on the Close button changing the property ControlBox of your form
Private Sub ClickMe(sender as Object, e as EventArgs) Handles Button1.Click
Me.ControlBox = True
End Sub
I'm filling the background of some VB.NET 2005 WinForms form with a nice pretty gradient fill (by overriding the OnPaint event). This works fine but the various labels etc on the form show with a solid background even after I set the BackColor to Color.Transparent. Setting the transparency key of the form itself seems to affect this but I cannot get the labels to have a truely transparent BackColor, is there an easy way to get around this or am I looking at custom controls etc?
Add a new class to your project and paste the code shown below. Build. Drop the new control from the top of your toolbox onto your form.
Public Class TransparentLabel
Inherits Label
Public Sub New()
Me.SetStyle(ControlStyles.Opaque, True)
Me.SetStyle(ControlStyles.OptimizedDoubleBuffer, False)
End Sub
Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
Get
Dim cp As CreateParams = MyBase.CreateParams
cp.ExStyle = cp.ExStyle Or &H20 ' Turn on WS_EX_TRANSPARENT
Return cp
End Get
End Property
End Class
The flicker might be noticeable, no fix.
After some experimentation I've found that the following works for gradiant filling form backgrounds and preserving label transparency:
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
Dim formGraphics As Graphics = e.Graphics
Dim gradientBrush As New LinearGradientBrush(New Point(0, Height), New Point(0, 0), Me.AppSettings.FormGradiantFrom, Me.AppSettings.FormGradiantTo)
formGraphics.FillRectangle(gradientBrush, ClientRectangle)
End Sub
And in the form load event:
SetStyle(ControlStyles.AllPaintingInWmPaint Or ControlStyles.DoubleBuffer Or _
ControlStyles.ResizeRedraw Or ControlStyles.UserPaint, True)