When the user right clicks on a ToolStripMenuItem (which is part of another ToolStripMenu), I want to show a new ToolStripMenu.
I'm using Visual Basic
I tried creating a ToolStripMenu and adding an Items in code. But when right clicking (on the ToolStripMenuItem) I cannot see the new ToolStripMenu. Is it maybe because I didn't define the location where the new ToolStripMenu should be visible?
THE CODE:
Private Sub RappelVerkoopfacturenToolStripMenuItem_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs)
If e.Button = System.Windows.Forms.MouseButtons.Right Then
Dim tsFavorites As New ToolStrip
tsFavorites.Items.Add("Add to favorites")
tsFavorites.Show()
End If
End Sub
You have to add the new ToolStrip to the Forms´ controls:
Me.Controls.Add(tsFavorites)
Additionally you don´t have to call the Show() method. Change visibility with the Visible property:
tsFavorites.Visible = True
(Nevertheless, the control is visible after adding it to the controls of the form by default. So you don´t have to set it explicitly.)
Related
I Intended to display an PictureBox in my form when the mouse hovered over another control. I then wanted to use a separate event for when the mouse left the control. This event would remove the displayed PictureBox from controls. However, because my events are private subs, I can't directly access the name of the control in the latter event. A solution to this would be a method that removes the most recently added control. If no such method exists, or there is an alternative way of approaching this problem, any help would be appreciated.
I tried simply using Controls.Remove(), but this requires a parameter. The name of the control as a string did not work either, as the parameter must be a control itself.
Private Sub Tile_MouseEnter(Sender As Object, e As EventArgs)
Dim CloseUpPic As New PictureBox With {Properties}
CloseUpPic.Image = Sender.Image
Controls.Add(CloseUpPic)
Refresh()
End Sub
Private Sub Tile_MouseLeave(Sender As Object, e As EventArgs)
Me.Controls.Remove()
End Sub
The program won't compile due to .Remove() needing a parameter
I expected for the Control to be created and displayed when the mouse entered the tile, and to cease to exist when the mouse left the tile.
For future reference, controls have Tag property which allows you to store whatever you like. In this case, you can store a reference to the newly created PictureBox. Furthermore, the "Sender" parameter tells you which control was the source of the event. You can cast sender to a control, then store the reference. Then, in the leave event, you can cast sender to a control, cast the .Tag to a control, and finally remove it:
Private Sub Tile_MouseEnter(Sender As Object, e As EventArgs)
Dim ctl As Control = DirectCast(Sender, Control)
Dim CloseUpPic As New PictureBox With {Properties}
CloseUpPic.Image = Sender.Image
Controls.Add(CloseUpPic)
ctl.Tag = CloseUpPic
Refresh()
End Sub
Private Sub Tile_MouseLeave(Sender As Object, e As EventArgs)
Dim ctl As Control = DirectCast(Sender, Control)
Dim ctlToRemove As Control = DirectCast(ctl.Tag, Control)
Me.Controls.Remove(ctlToRemove)
End Sub
I ended up using the following code to solve my issue:
For Each Closeup In Controls.OfType(Of CloseUp)
Controls.Remove(Closeup)
Next
I created a new class of my own called Closeup, that inherits PictureBox. I then looped through each Closeup in controls (There was only one but this code works for multiple controls), and removed them.
I have a generic message box where we have a few panels in which we add controls at runtime.
Here in my form, I've already pnlBottom on which pnlButtons is there along with some other controls.
Now at run time I'm adding an OK button to pnlButtons which is there on pnlBottom. I'm not setting a TabIndex for any controls in the Designer.vb file.
I'm trying to keep the focus on the OK button using the code below, but it's not working.
For Each control As Control In Me.Controls
If TypeOf (control) Is Panel Then
Dim pnlBottons As Panel = CType(control, Panel)
If pnlBottons.Name = "pnlBottom" Then
For Each ctrl As Control In control.Controls
Dim pnlButtons As Panel = CType(ctrl, Panel)
If pnlButtons.Name = "pnlButtons" Then
For Each ctrlbtn As Control In ctrl.Controls
If TypeOf (ctrlbtn) Is Button Then
Dim textBox As Button = CType(ctrlbtn, Button)
textBox.Parent.Parent.TabIndex = 0
textBox.Parent.TabIndex = 0
textBox.TabIndex = 0
End If
Next
End If
Next
End If
End If
Next
Here I'm setting the TabIndex for pnlBottom, pnlButtons and OK button as 0.
Please suggest how to focus the OK button.
You can set the focus on a control during Form Load event using either of the following options. (Ref: How to set the focus on a control when the form loads in Visual Basic .NET or in Visual Basic 2005. The original link is broken, so use Wayback Machine.)
1- Control.Select Method
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Mybase.Load
Me.OKButton.Select()
End Sub
Focus is a low-level method intended primarily for custom control
authors. Instead, application programmers should use the Select method
or the ActiveControl property for child controls, or the Activate
method for forms.
2- Form.ActiveControl Property
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Mybase.Load
Me.ActiveControl = Me.OKButton
End Sub
3- Control.Focus Method
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Mybase.Load
Me.Show()
Me.OKButton.Focus()
End Sub
The reason that we call Me.Show() is to set forms visible to true. according to:
You can use the Control.Focus method in the Load event of the form to
set the focus on a control only after the Visible property of the form
is set to True.
In cases you can not use Me.OKButton you can find the control you want like this:
Dim control = Me.Controls.Find("OKButton", True).FirstOrDefault()
If Not control Is Nothing Then
control.Select() 'or other stuff
End If
Ive seen some discussion on here about how to hide tabs in a tabcontrol but they all seem to be in C or some variant. I havent seen one for vb.net (i cant do C)
What i want to do is hide or disable all some of the tabs till the user has logged in.
Ive sorted out the login and logout. All i need to do is add the code to enable/disable some tabs until the user has logged in.
Anyone know a good way to do this?
WinForms btw
You just add and remove TabPages from the TabControl through the TabPages collection:
TabControl1.TabPages.Add(myTabPage)
and to remove it:
TabControl1.TabPages.Remove(myTabPage)
Note: Removing a TabPage does not dispose it, it just removes it from the TabPage collection.
Currently, the following code block disables all the controls on that TabPage (Sets Control.Enabled = False). The tab itself is still visible and selectable from the TabControl, it is not hidden. The tab is selectable and all the elements appear disabled.
TabMyTab.Enabled = False
If you want to disable the tab similar to i.e. button.Enabled = False which does not allow the control to be used, you will need to do something different as disabling a TabPage as in the code above disables all controls in that tab. If this is what you want, keep reading. A lot of programmers suggest using the TabControl to disallow the tab from being selected by selecting a different or the previously selected tab. This is the most effective way I know. I would implement this as follows:
Private PreviousTab As New TabPage
Private CurrentTab As New TabPage
Private Sub TabControlName_Deselected(ByVal sender As Object, ByVal e As System.Windows.Forms.TabControlEventArgs) Handles TabControlName.Deselected
PreviousTab = e.TabPage
End Sub
Private Sub TabControlName_Selected(ByVal sender As Object, ByVal e As System.Windows.Forms.TabControlEventArgs) Handles TabControlName.Selected
CurrentTab = e.TabPage
If (PreviousTab.Name <> CurrentTab.Name) And (CurrentTab.Name = UnselectableTab.Name) Then
MessageBox.Show("Tab disabled.", "Selection Error", MessageBoxButtons.OK, MessageBoxIcon.Warning)
TabControlName.SelectedTab = PreviousTab
End If
End Sub
Substitute your own values for "UnselectableTab" and "TabControlName" for your project.
Just hide the whole TabControl by setting its Visible property
I've 100 buttons created dynamically in a form. How can I an add event handler to them?
You can use AddHandler to add a handler for any event.
For example, this might be:
AddHandler theButton.Click, AddressOf Me.theButton_Click
Just to round out Reed's answer, you can either get the Button objects from the Form or other container and add the handler, or you could create the Button objects programmatically.
If you get the Button objects from the Form or other container, then you can iterate over the Controls collection of the Form or other container control, such as Panel or FlowLayoutPanel and so on. You can then just add the click handler with
AddHandler ctrl.Click, AddressOf Me.Button_Click (variables as in the code below),
but I prefer to check the type of the Control and cast to a Button so as I'm not adding click handlers for any other controls in the container (such as Labels). Remember that you can add handlers for any event of the Button at this point using AddHandler.
Alternatively, you can create the Button objects programmatically, as in the second block of code below.
Then, of course, you have to write the handler method, as in the third code block below.
Here is an example using Form as the container, but you're probably better off using a Panel or some other container control.
Dim btn as Button = Nothing
For Each ctrl As Control in myForm.Controls
If TypeOf ctrl Is Button Then
btn = DirectCast(ctrl, Button)
AddHandler btn.Click, AddressOf Me.Button_Click ' From answer by Reed.
End If
Next
Alternatively creating the Buttons programmatically, this time adding to a Panel container.
Dim Panel1 As new Panel()
For i As Integer = 1 to 100
btn = New Button()
' Set Button properties or call a method to do so.
Panel1.Controls.Add(btn) ' Add Button to the container.
AddHandler btn.Click, AddressOf Me.Button_Click ' Again from the answer by Reed.
Next
Then your handler will look something like this
Private Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
' Handle your Button clicks here
End Sub
#Debasish Sahu, your answer is an answer to another question, namely: how to know which button (or any other control) was clicked when there is a common handler for a couple of controls? So I'm giving an answer to this question how I usually do it, almost the same as yours, but note that also works without type conversion when it handles the same type of Controls:
Private Sub btn_done_clicked(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim selectedBtn As Button = sender
MsgBox("you have clicked button " & selectedBtn.Name)
End Sub
I needed a common event handler in which I can show from which button it is called without using switch case... and done like this..
Private Sub btn_done_clicked(ByVal sender As System.Object, ByVal e As System.EventArgs)
MsgBox.Show("you have clicked button " & CType(CType(sender, _
System.Windows.Forms.Button).Tag, String))
End Sub
Some code for a variation on this problem. Using the above code got me my click events as needed, but I was then stuck trying to work out which button had been clicked.
My scenario is I have a dynamic amount of tab pages. On each tab page are (all dynamically created) 2 charts, 2 DGVs and a pair of radio buttons. Each control has a unique name relative to the tab, but there could be 20 radio buttons with the same name if I had 20 tab pages. The radio buttons switch between which of the 2 graphs and DGVs you get to see. Here is the code for when one of the radio buttons gets checked (There's a nearly identical block that swaps the charts and DGVs back):
Private Sub radioFit_Components_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
If sender.name = "radioFit_Components" And sender.visible Then
If sender.checked Then
For Each ctrl As Control In TabControl1.SelectedTab.Controls
Select Case ctrl.Name
Case "embChartSSE_Components"
ctrl.BringToFront()
Case "embChartSSE_Fit_Curve"
ctrl.SendToBack()
Case "dgvFit_Components"
ctrl.BringToFront()
End Select
Next
End If
End If
End Sub
This code will fire for any of the tab pages and swap the charts and DGVs over on any of the tab pages. The sender.visible check is to stop the code firing when the form is being created.
there is a feature I'd like to implement in my application:
The user right clicks on my picturebox object. Good.
When that happens, some code of mine executes and will generate a list of options.
Then a menu appears where the mouse right-clicked, made up of these options.
When the user clicks on one of these options, the menu is deleted and some code is run given the option index as parameter.
My two problems:
How can I tell when the user right clicks? I can see an event handler for "click", but that includes left clicks....
How do I create one of these menus? I mean, go ahead and right click something. That's the kind of menu I'm looking for.
You need to implement the picturebox' MouseUp event. Check if the right button was clicked, then create a ContextMenuStrip with the menu items you want. You can use, say, the Tag property of the items you add to help identify them so you can give them a common Click event handler. Like this:
Private Sub PictureBox1_MouseUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
If e.Button <> Windows.Forms.MouseButtons.Right Then Return
Dim cms = New ContextMenuStrip
Dim item1 = cms.Items.Add("foo")
item1.Tag = 1
AddHandler item1.Click, AddressOf menuChoice
Dim item2 = cms.Items.Add("bar")
item2.Tag = 2
AddHandler item2.Click, AddressOf menuChoice
'-- etc
'..
cms.Show(PictureBox1, e.Location)
End Sub
Private Sub menuChoice(ByVal sender As Object, ByVal e As EventArgs)
Dim item = CType(sender, ToolStripMenuItem)
Dim selection = CInt(item.Tag)
'-- etc
End Sub
To your first question: you actually handle just the "click" event, there is no separate event for right-click. But look at the EventArgs object you get passed for the event: it includes information of which button was pressed (and would give you more info if a mouse click had anything beyond that). So you check the button within an if block, and you're good to go.
To your second question: http://msdn.microsoft.com/en-us/library/system.windows.forms.contextmenustrip.aspx. If your menu is pre-defined, just look for that component on the Designer and prepare the menu from there and call its Show() method from the click handler. If you need to decide the menu entries on the fly, the linked documentation page actually includes an example on that ;)
PS: oops, I just noticed Jon's comment on the question. The answer I gave you is for Windows Forms. If you are on WPF let us know and I'll update with the details (although the concepts ain't too different).
There is actually an easier way to do this. Double-click on the control you wish to be able to right click. Now go to the top of the page and it should say in comboboxes; 'Control' and 'Click' Click on the 'click' combobox and look for: Right-Click. Use a ContextMenuStrip for your right click menu.
Now you can choose which function you want.
Private Sub PictureBox1_RightClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.RightClick
ContextMenuStrip1.Show()
MsgBox("Content Activated.", MsgBoxStyle.Information, "Success!")
End Sub
Hope I could help. :)
Coridex73