I have an application that is a part of a solution of projects. In this project I would like for it to start up form to be invisible, but still have a notification icon in the tray visible for this form.
I know that adding me.hide into the form_load doesn't work. I tried adding a module that instantiates the startup form and I set it as the startup object. Although that didn't work either. I am running out of ideas to have this form invisible. Could anyone help out? I am using VB.NET.
Paste this in your form code:
Protected Overrides Sub SetVisibleCore(ByVal value As Boolean)
If Not Me.IsHandleCreated Then
Me.CreateHandle()
value = False
End If
MyBase.SetVisibleCore(value)
End Sub
The way that works is that the very first request to show the form, done by the Application class, this code overrides the Visible property back to False. The form will behave as normal after this, you can call Show() to make it visible and Close() to close it, even when it was never visible. Note that the Load event doesn't fire until you show it so be sure to move any code in your event handler for it, if any, to the constructor or this override.
Put this in the form's Shown event
Me.Visible = False
The easiest way is to set the opacity of the form to 0%. When you want it to appear, set it back to 100%
Here is another way that I've found to do this.
Set the form properties with
ShowInTaskbar = False
Then in the form's constructor add
WindowState = FormWindowState.Minimized
This is very easy to implement and works with no flicker. In my case I also use a NotifyIcon to access the program from the notification tray and just set
WindowState = FormWindowState.Normal
Show()
BringToFront()
In the Notify_MouseClick event handler.
To hide the form again after displaying it, just minimizing again doesn't quite do the job. In my case I use the Form_Closing event and just hide the form.
Hide()
Use Me.Opacity = 0 to hide the form on load event.
Then use the following code in the form.Shown event
Me.Hide()
Me.Opacity = 100
Just to throw out a completely different approach, have you considered not using the overload of Application.Run() that takes (and automatically shows) a Form? If you use the one that passes in an ApplicationContext (or more tyoically, your own subclass of ApplicationContext) then you can choose what your behavior is. See here for more details:
http://msdn.microsoft.com/en-us/library/ms157901
Try this:
Sub New()
MyBase.SetVisibleCore(False)
End Sub
Related
I have an issue that I cannot seem to overcome.
In my application, I have a custom class that loads a form into a panel upon startup. Then when I click a button on my main form I show the panel as visible revealing the form to the user.
My problem is that I want to be able to hide the panel when a user clicks outside of it (back onto the main form).
so far I have tried Form_Deactivate, Form_Leave, Form_LostFocus, Panel_Leave and Panel_LostFocus events but nothing will seem to trigger an event consistently to hide the panel. The only thing that works is if the user clicks inside the form (on a listview control) once the form is visible and then clicks outside of the form.
Is there anyway I can ensure this event gets called everytime whether the user clicks the form or not?
So far my code looks something like:
Public Class cls_UserObjects
Private frm As frmUsers
Public pnl As Panel
Public Sub ShowUserPanel()
Try
frm = New frmUsers
frm.TopLevel = False
pnl.Controls.Add(frm)
frm.Show()
frm.Focus()
....
End Class
Then in my main form I call the code below to build the form into the panel:
class_Users.pnl = pnlUsers
class_Users.ShowUserPanel()
And pnlUsers.Visible = True to show it to the user
I just can't seem to close it. I understand that Panels don't support the LostFocus properly, however, I can't find away around this. Maybe it has something to do with how I am opening my form/panel but I was advised to use classes to open forms so I can have more control over the controls within my forms from outside calls.
Any help appreciated. Thanks
MouseLeave event works, the panel hides immediately once it leaves the panel.
Private Sub Panel1_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles Panel1.MouseLeave
Panel1.Visible = False
End Sub
Does anyone know of a way to disable the mouse scroll wheel when a control such as a combobox or listbox has focus? For my purposes, combobox is all I need the answer for.
I have a combobox set to trigger a SQL query on SelectedIndexChanged, and accidentally scrolling the wheel while the combobox has focus causes about six SQL queries to fire off simultaneously.
I've found a mix response, put this code in the MouseWheel event:
Dim mwe As HandledMouseEventArgs = DirectCast(e, HandledMouseEventArgs)
mwe.Handled = True
That's all. You don't need to create a new class, if you have your project in an advanced state.
The ComboBox control doesn't let you easily override behavior of the MouseWheel event. Add a new class to your project and paste the code shown below. Compile. Drop the new control from the top of the toolbox onto your form.
Friend Class MyComboBox
Inherits ComboBox
Protected Overrides Sub OnMouseWheel(ByVal e As MouseEventArgs)
Dim mwe As HandledMouseEventArgs = DirectCast(e, HandledMouseEventArgs)
mwe.Handled = True
End Sub
End Class
Beware that this also disables the wheel in the dropdown list.
If you subclass the control it's possible (apologies for the C#)
public class NoScrollCombo : ComboBox
{
[SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode = true)]
protected override void WndProc(ref Message m)
{
if (m.HWnd != this.Handle)
{
return;
}
if (m.Msg == 0x020A) // WM_MOUSEWHEEL
{
return;
}
base.WndProc(ref m);
}
}
One such option would be to add a handler to the comboBox, and within that comboBox, resolve the situation. I'm not sure how your code is set up, but I'm assuming if you knew when the event was happening, you could set up some kind of conditional to prevent the queries from happening
'''Insert this statement where your form loads
AddHandler comboBoxBeingWatched.MouseWheel, AddressOf buttonHandler
Private Sub buttonHandler(ByVal sender As System.Object, ByVal e As System.EventArgs)
'''Code to stop the event from happening
End Sub
In this way, you'd be able to maintain the user being able to scroll in the comboBox, but also be able to prevent the queries from happening
Combining all the answers on this thread, the best solution if you don't want to create a custom control is to handle the mousewheel event. The below will also allow the list to be scrolled if it is dropped down.
Assuming your combobox is called combobox1:
If Not ComboBox1.DroppedDown Then
Dim mwe As HandledMouseEventArgs = DirectCast(e, HandledMouseEventArgs)
mwe.Handled = True
End If
I had the exact same issue, but found that simply changing the focus of the control after the query executed to another control such as the "Query" button itself worked better than perfect. It also allowed me to still scroll the control until the SelectedIndex actually changed and was only one line of code.
Just put this in the mousewheel event or in a single handler for all the controls this applies to, maybe call it wheelsnubber.
DirectCast(e, HandledMouseEventArgs).Handled = True
Can you please tell me how I can reload a windows form without closing it using VB.NET?
Put all your initialization code into a method and not the constructor or the Form.Load event and just call that method. This can also include the designer-generated InitializeComponent() method which sets up all controls on the form. You should remove all controls on the form as your first action in that method, though.
I know that it is late, but useful
Me.Controls.Clear() 'removes all the controls on the form
InitializeComponent() 'load all the controls again
Form1_Load(e, e) 'Load everything in your form, load event again
You cannot do that.
Why do you want to reload a form? Do you want to clear all input controls or something like that? The simplest solution might be to just do the clearing by hand.
Alternatively, you can put all your controls into a user control container. Then just instantiate that user control on your form. If you want to reload your form content, you now just need to remove and re-instantiate the user control.
Application.Restart()
Shuts down the application and immediately opens a new instance.
try using Me.Refresh() it worked with me
Me.Controls.Clear() 'removes all the controls on the form
InitializeComponent() 'load all the controls again
main_Load(e, e)
MsgBox("Thank you for sending report", vbInformation, "")
Refresh()
I know. I'm late to the party. But, maybe it works for who need it.
If you shows a form from other form with .ShowDialog the code after this call will be executed when the form that has been showed is closed. Example:
Private Sub button1_Click(sender As Object, e As EventArgs) Handles button1.Click
Dim form2 As New Form2
form2.ShowDialog
UpdateThisForm()
End Sub
Then it's not necessary update the form from the other form (Form2).
Execute the following line:
Form_Load(sender, e)
I have been asked to remove or disable the close button from our VB .NET 2005 MDI application. There are no native properties on a form that allow you to grey out the close button so the user cannot close it, and I do not remember seeing anything in the form class that will allow me to do this.
Is there perhaps an API call or some magical property to set or function to call in .NET 2005 or later to do this?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
More information:
I need to maintain the minimize/maximize functionality
I need to maintain the original title bar because the form's drawing methods are already very complex.
Based on the latest information you added to your question, skip to the end of my answer.
This is what you need to set to false: Form.ControlBox Property
BUT, you will lose the minimize and maximize buttons as well as the application menu (top left).
As an alternative, override OnClose and set Cancel to true (C# example):
protected override void OnFormClosing(FormClosingEventArgs e)
{
if (e.CloseReason != CloseReason.WindowsShutDown && e.CloseReason != CloseReason.ApplicationExitCall)
{
e.Cancel = true;
}
base.OnFormClosing(e);
}
If neither of these solutions are acceptable, and you must disable just the close button, you can go the pinvoke/createparams route:
How to disable close button from window form using .NET application
This is the VB version of jdm's code:
Private Const CP_NOCLOSE_BUTTON As Integer = &H200
Protected Overloads 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
You can disable the close button and the close menu item in the system menu by changing the "class style" of the window. Add the following code to your form:
const int CS_NOCLOSE = 0x200;
protected override CreateParams CreateParams {
get {
CreateParams cp = base.CreateParams;
cp.ClassStyle |= CS_NOCLOSE;
return cp;
}
}
This will not just stop the window from getting closed, but it will actually grey out the button. It is C# but I think it should be easy to translate it to VB.
Here is a simple way to remove the close button:
1. Select the Form
2. Now go to Properties.
3. Find ControlBox and change the value to False.
This will remove all the Control Buttons (e.g. Minimize, Maximize, Exit) and also the icon also that is in the to left corner before the title.
You should be able to override the OnClose event of the form. This is common when an application minimizes to the System Tray when "closed".
When you press the X box on the form.
The Form1_Closing is done first, then the Form1_Closed is done.
The e.Cancel = True in the Form1_Closing - prevents Form1_Closed from being called therefore, leaving your form still active.
Prevent to close the form, but hide it:
Private Sub Form1_Closing(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
Me.WindowState = FormWindowState.Minimized
Me.Visible=false
e.Cancel = True
End Sub
You can set the ControlBox property to False, but the whole title bar will be gone but the title itself...
What jmweb said here is OK as well. The X close button won't go if you cancel the event on form closing. But doing so, you need to release the processes the form needs and then closing the form.
Me.Dispose()
Me.Close()
This worked for me using Menu Strip.
Select (or click) the form itself
Click on events in the property window (the little lightning bolt icon).
Look for Form.Closing and double click it.
Then type: e.cancel=true
Making a Form without a Titlebar in Visual Basic.
Go to Form Properties and set both ControlBox and ShowIcon to false.
Then, clear all the text from the form's text property.
go to properties and select from bored style as none
Just select the required form and in the properties section, set controlBox = false
That just worked for me :)
Private Sub Form1_Closing(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
Beep()
e.Cancel = True
End Sub
Is there a way to force a form to be active and shown?
From another form i am doing:
Me.Hide
Form2.Show
When this code is run, the Form2 is minimized.
I've also tried:
Me.WindowState = FormWindowState.Normal
in the load event, and it still loaded it in minimized mode.
Try Me.BringToFront(); or you can set the property TopMost true and thus the form will be always on top.