I'm new to .net and I am developing my library dll testing it against a test application for gaining experience etc.... I apologize in advance if I am not using the correct terms in my message.
As I want to add some custom properties to all my future forms I created a custom form with some extra properties.
I then create a form based on the new custom form and compared the .designer.vb files. I found that changing inherits system.windows.forms.form to inherits library.Myform should do it but I also found another difference:
Both designer files contain code to dispose components however they are slightly different:
designer generated for form based on system.windows.forms.form:
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
Try
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
End If
Finally
MyBase.Dispose(disposing)
End Try
End Sub
the one for the form based on library.Myform:
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
End If
MyBase.Dispose(disposing)
End Sub
Why that difference and should I modify my forms created from the custom form so that they contain the Try-Finally block. If yes is there a way to change the behavior of vs to do it when creating the form based on the custom form.
Related
I have read through several forums and tried different options. Most of the answers were this, which makes me assume that would be the issue. I placed Application.EnableVisualStyles()
at the beginning of InitializeComponent() in the .Designer.vb file as seen below:
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()>
Partial Class MetadataCollectionGUI
Inherits System.Windows.Forms.Form
'Form overrides dispose to clean up the component list.
<System.Diagnostics.DebuggerNonUserCode()>
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
Try
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
End If
Finally
MyBase.Dispose(disposing)
End Try
End Sub
'Required by the Windows Form Designer
Private components As System.ComponentModel.IContainer
'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
<System.Diagnostics.DebuggerStepThrough()>
Private Sub InitializeComponent()
Application.EnableVisualStyles() ' <--- See Here
Me.ListViewMetaDataCollection = New System.Windows.Forms.ListView()
Me.ColumnTags = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
etc... etc...
End Sub
Etc...
End Class
Did I misunderstand how to execute that particular solution or is the issue something different?
I found out what the issue was. Go to the project properties and enable the application framework. Now you can enabled the XP visual styles.
Thank you Hursey & jmcilhinney, I would not have figured it out without you all!
how do i set panel transparent like opacity to 0. i set the panel by program and it was on top of video player. the code is like this
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click ', AxVLCPlugin21.Click
Dim panelx As New Panel
panelx.Visible = True
panelx.Size = New Size(AxVLCPlugin21.Width, CInt(AxVLCPlugin21.Height / 2))
panelx.BackColor = System.Drawing.Color.Transparent
AxVLCPlugin21.Controls.Add(panelx)
panelx.BringToFront()
'AddHandler panelx.DoubleClick, AddressOf panelx_click
End Sub
the result is like this
then i try to play the video it only show the half
the reason i use panel is to pause the video (set panel on top of video by transparent), when i click the panel since the video doesn't support click event
update
i put the code in usercontrol1
still got me an error, although i have insert the code in designer. too clarify i put the code designer after below the main designer code. i have tried to put only inherit panel code in main designer code but it only take one inherit only.
The best way to do this is to create a custom control that inherits the panel class and overrides CreateParams and OnPaintBackground with this bit of code:
(Props to Zohar Peled for his post here)
Replace the code behind with:
Public Class TransparentPanel
Inherits System.Windows.Forms.Panel
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
End Class
And replace the designer code with:
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()>
Partial Class TransparentPanel
Inherits System.Windows.Forms.Panel
'Control overrides dispose to clean up the component list.
<System.Diagnostics.DebuggerNonUserCode()>
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
Try
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
End If
Finally
MyBase.Dispose(disposing)
End Try
End Sub
'Required by the Control Designer
Private components As System.ComponentModel.IContainer
' NOTE: The following procedure is required by the Component Designer
' It can be modified using the Component Designer. Do not modify it
' using the code editor.
<System.Diagnostics.DebuggerStepThrough()>
Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
End Sub
End Class
The code you're replacing may look different initially, but using this code will ensure everything works.
NOTE: This code will make the panel transparent if the backcolor is set to Transparent or Control (which depending on the control is normally actually the same as transparent.)
I tried to find an updated resource for creating and implementing a custom control, but I wasn't able to find a maintained resource. So here are some step by step instructions on how to create a custom control.
To create custom control usable in the designer:
(I'm using Visual Studio 2015 for the examples below, it may appear different in other versions.)
1. Create new Windows Forms Control Library
2. Then right click and rename your control to "TransparentPanel" (or
whatever name you like)
3. Paste the code above into the code behind and the designer code respectively (changing the class name if you didn't use "TransparentPanel")
4. Build the project (this will create the .dll you will need to reference in your main project)
5. This one is optional, but it is good to store your DLLs somewhere consistent, other than the project bin folder, so, optionally, navigate to the control library bin folder and copy the created DLL to another location you want to store your custom DLLs.
6. Go to the project you want to use the control in, and right click in the toolbox and click "Choose Items..."
7. Make sure you are on the the ".NET Framework Component" tap and select "Browse".
8. Navigate to the bin folder of the control library (or where ever you stored the DLL), select the control and click "Open".
9. You will see the TransparentControl selected now in the "Choose Toolbox Items" form. Click "OK"
10. Then you should be able to find the control under "General" section.
11. Drag and drop the control onto your form.
NOTE:
The control may not look transparent in the designer, but on runtime it should do what you are looking for.
I hope this works for you!
Can I maintain vb.net windows form designer code in .vb?
i.e I wanted to ask whether I can maintain only one .vb file for both form design and logic part, instead of having one designer.vb for form design part and .vb file for logic part?
Here is a functional sample:
_
Partial Class Form1
Inherits System.Windows.Forms.Form
'Required by the Windows Form Designer
Private components As System.ComponentModel.IContainer
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
Try
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
End If
Finally
MyBase.Dispose(disposing)
End Try
End Sub
Public Sub Intiialize()
'Form overrides dispose to clean up the component list.
InitializeComponent()
'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
End Sub
<System.Diagnostics.DebuggerStepThrough()> _
Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
Me.Text = "Form1"
End Sub
End Class
I'm reasonably new to programming and soon I will be creating a program and would like to change the colour of a selected row via a button click.
I have been attempting this but I don't even know where to begin. If someone could point me in the correct direction it would be much appreciated.
Thanks ^.^
You could simply create a new control, then change the designer to inherit from the listbox control.
the designer code would then look something like this (vs2010):
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Class UserControl1
Inherits ListBox
'UserControl overrides dispose to clean up the component list.
<System.Diagnostics.DebuggerNonUserCode()> _
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
Try
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
End If
Finally
MyBase.Dispose(disposing)
End Try
End Sub
'Required by the Windows Form Designer
Private components As System.ComponentModel.IContainer
'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
<System.Diagnostics.DebuggerStepThrough()> _
Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
End Sub
End Class
To see the designer code, select "Show All Files" (button at the top of your solution explorer). Then expand the new control node in your solution explorer.
then change the line:
Inherits System.Windows.Forms.UserControl
to:
Inherits ListBox
and finally delete delete the line:
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
Hope that helps.
I have a class clsContextPopUpMenu to create a ContextMenuStrip with some basic functions (e.g.copy) that I can use in different controls.
Friend Sub New(ByRef objControl As System.Windows.Forms.Control)
m_objControlContainer = objControl
m_mnuCopyCell2Clipboard = New ToolStripMenuItem("Copy Cell")
m_PopupMenu = New ContextMenuStrip
m_PopupMenu.Items.AddRange(New ToolStripMenuItem() {m_mnuCopyCell2Clipboard})
End Sub
For example, I can use it in a DataGridView DGVTable:
Private m_objPopUpMenu As clsContextPopUpMenu
m_objPopUpMenu = New clsContextPopUpMenu(CType(DGVTable, System.Windows.Forms.Control))
However, note that m_objPopUpMenu IS NOT associated with the form having the above datagridview. According to ContextMenuStrip constructor explanation in MSDN, I think that m_objPopUpMenu cannot be disposed automatically since it is not a child of the form.
My question is, do I have to explicitly dispose m_objPopUpMenu in designer:
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
Try
If disposing AndAlso components IsNot Nothing Then
components.Dispose()
**m_objPopUpMenu.Dispose()**
End If
Finally
MyBase.Dispose(disposing)
End Try
End Sub
A broader question is that when should I dispose objects/resource by myself? Of course, gc collector is not a magician to release all available memory. Can I always dispose objects/resource in Dispose Sub as shown above?
Revised answer due to better understanding of issue:
Because the ContextMenuStrip implements IDisposable, you will either need to add it to the list of Components managed by the form so that it is disposed appropriately and automatically or manage the disposal yourself as suggested in your original question.
Here is a revision of your class that will support the automatic disposal in the same way that windows would handle it if you were to add ContextMenuStrip directly to the form:
Friend Sub New(ByVal objControl As System.Windows.Forms.Control, ByVal components As System.ComponentModel.IContainer)
m_objControlContainer = objControl
m_mnuCopyCell2Clipboard = New ToolStripMenuItem("Copy Cell")
m_PopupMenu = New ContextMenuStrip(components)
m_PopupMenu.Items.AddRange(New ToolStripMenuItem() {m_mnuCopyCell2Clipboard})
End Sub
To call this new constructor from within your form or user control:
Private m_objPopUpMenu As clsContextPopUpMenu
m_objPopUpMenu = New clsContextPopUpMenu(DGVTable, Me.components)
Note that I also removed the ByRef from the constructor since it is not required, which also eliminates the need to cast the controls before passing them to the constructor.
One additional note: it used to be ("back in the day") that components was not necessarily present on every form or user control. I believe that this has changed/been fixed, but if you find yourself without, it is easy to add manually:
Private components As System.ComponentModel.IContainer
In your constructor:
Me.components = New System.ComponentModel.Container()
In your Dispose method (I have added the full dispose method in case it is not already present; if it is, just added the components-related code):
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub