I'm quite new to programming, so I'm facing a lot of problems such as this one:
After clicking button1, the program should assign the next pushed key(ctrl, for example) to button1.text.
For example: Click button1 -> push key X -> button1.text = X
What I have so far:
Private Sub btnTaste1_keydown(sender As Object, e As System.Windows.Forms.KeyEventArgs) Handles btnTaste1.KeyDown
btnTaste1.Text = e.KeyCode.ToString
End Sub
But that assigns a pushed key at any time, not only after clicking the button.
I think the best way to do this would be to dynamically add and remove the KeyDown handler.
Change your KeyDown to look like this (remove the Handles clause):
Private Sub btnTaste1_keydown(sender As Object, e As System.Windows.Forms.KeyEventArgs)
That will stop that code from automatically being run on every key press.
Now in your button click code, add this:
addhandler btnTaste1.Keydown, addressof(btnTaste1_keydown)
After you "handle" the key press you should detach the handler so it doesn't get called again (until the button click attaches it again), like this:
btnTaste1.Text = e.KeyCode.ToString
removeHandler btnTaste1.Keydown, addressof(btnTaste1_keydown)
Eventually you may want to investigate using the Form's KeyPreview property and attach the event to the form instead so that you don't need to worry about the complexities of input focus.
Related
I write this code for tab-like behavior when user presses ENTER on textboxes for every form, which works fine.
If e.KeyChar = Microsoft.VisualBasic.ChrW(Keys.Return) Then
SendKeys.Send("{TAB}")
e.Handled = True
End If
However, I need to write the code once, perhaps as a sub or function in a module so that I do not have to write the same for every form. I have checked various forums including
Detecting Enter keypress on VB.NET and
Tab Key Functionality Using Enter Key in VB.Net
BUT all I get is either to write code for each textbox or for every individual form.
Has anyone tried out a single code for ALL or may be several selected forms of the application? If yes, please share with me. Writing for every form still works fine for me but i need to take advantage of OOP. Thanks
There are many ways to implement this, one of those is to create a custom textbox User Control
Adding a control to your project is very easy just right click in your project in the solution explorer ->Add->User Control
Give a name to your control ex. "tabedtextbox"
Add a textbox control to your User Control
Place the code in the keypress event of textbox1 of the UserControl
Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles TextBox1.KeyPress
If e.KeyChar = Microsoft.VisualBasic.ChrW(Keys.Return) Then
SendKeys.Send("{TAB}")
e.Handled = True
End If
End Sub
Compile once in order to update the whole project with the new user control.
Goto to your form and add your new User Control, you can locate it at the Toolbox panel.
Run your program and you will see the behavior of TAB when you press enter on each textbox.
If You wish to allow the user to press enter in a TextBox, instead of pressing a specific button,
you can use the acceptbutton property.
One good way to use it, is to change the property, on the Enter and Leave events of the TextBox. That you call Click event of the Button, when User press Enter inside the TextBox.
Try this code:
Private Sub tbProject_Enter(sender As Object, e As EventArgs) Handles tbProject.Enter
Me.AcceptButton = bSearch
End Sub
Private Sub tbProject_Leave(sender As Object, e As EventArgs) Handles tbProject.Leave
Me.AcceptButton = Nothing
End Sub
Private Sub bSearch_Click(sender As Object, e As EventArgs) Handles bSearch.Click
'.... actions to perfom
End Sub
Screen
I'm having a application with quite a few tabpages. One function of my program is that if the user leaves the application for more than 3 minutes, I display the main tabpage where the most relevant information is shown (this is done by a timer called "back_to_main_tab"). So far so good. However in a few tabpages you can enter text and "take a pause" for more than these 3 minutes, and if that happens, the user is taken back to the main tab, without his/her consent, erasing his/her entered text.
I realize that this could be solved by enabling/disabling the back_to_main_tab-timer at strategic places, but I would like to solve it by resetting the timer each time a click is registered in the application regardless of what is is clicked. The reason for this is that the problem isn't unique for a certain tabpage, so I would like to have a "all-purpose"-fix for all tabpages.
Is this possible?
Thanks in advance
Jonas
You can write an Event Handler for each element where user can write.
For example
Private Sub TextBox1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
'Reset timer
End Sub
(and you could try KeyUp or KeyPress too).
So you can reset timer each time the user write something somewhere.
Btw if the 3mins pass (after last KeyPress), the back_to_main_tab erase all.
EDIT
Ok so you could make one function to Manage the CLICK event. And attach the function to all items form.
To attacch an event handler to alla element you could try something like this
Private Sub AddGenericEventHandler()
For Each Ctrl As Item In Form.Items
AddHandler Ctrl.Click, AddressOf MyClickHandler
Next
End Sub
And write the function that reset your timer
Public Sub MyClickHandler(ByVal sender As System.Object, ByVal e As System.EventArgs)
'Timer Reset
End Sub
This is an Idea. You have to write correctly the FOR EACH to catch all form items do you need.
I have a Visual Studio, Visual Basic form that includes an OK button and a Cancel button.
What I want to do is have the OK button save the options that the user chooses and of course the Cancel button discarding them and returning them to their previous values.
But what I'm noticing is that as I'm debugging the form, the values are being saved regardless of whichever button I'm choosing. On the form's properties, I have declared that indeed the CancelBtn is the CancelBtn and that the OK button is the OK button, but the values are still being saved regardless.
Is there a better way to do what I would like this form to do?
EDIT:
Here's the code so far for the two buttons, both are being set to close the window. AcceptOption should save the values and CancelOption should just close the form. I'm sorry if this isn't done well but the FAQ's that I found only mention changing the properties of each button and nothing about the code.:
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles AcceptOptionBtn.Click
' Save the Options
Me.Close()
' Close the form
End Sub
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles CancelOptionBtn.Click
' Close the form
Me.Close()
End Sub
Don't change "the values" until the user clicks the Save button.
The form should be preloaded with a copy of the values you would like to update.
The Cancel button should just close the form.
The Save button should cause "the values", not the forms copy, to be updated.
EDIT:-
In regard to this question, there is nothing wrong with the code you have posted. Are the right handlers being called for the right button clicks? Are the form's AcceptButton and CancelButton properties set to the right buttons?
What data are your editing controls bound to, if at all?
There's nothing magical about OK and Cancel buttons. They're just... buttons. If you save your data every time a change is made, the Cancel button won't magically "unsave" them. Though if you save changes in the OK button's Click event handler, then clicking the Cancel button obviously won't save your changes. To help you further we'd need to know how you save your data.
Edit:
From looking at your code, I think you're passing data directly to your form, without performing a copy of your objects. Therefore if you modify this data, it will also be changed in the parent form. By working with a copy of your data in this form, any changes which aren't saved will be correctly discarded.
Your event handler for the cancel button should look like this:
Private Sub btnCancel_Click(sender As System.Object, e As System.EventArgs) Handles btnCancel.Click
Me.Close()
End Sub
Your event handler for the OK button should look like this:
Private Sub btnOK_Click(sender As System.Object, e As System.EventArgs) Handles btnOK.Click
SaveSettings 'call a routine to save the settings the user has entered
Me.Close()
End Sub
It is as simple as that!
If you open your form like
myForm.showdialog()
you don't have to define the handler for the close button click event, it is automatically handled; just set the 'DialogResult' property for the button
btnCancel.DialogResult = DialogResult.Cancel
Also if you want to close the form when ESC is pressed then set the 'CancelButton' property for the form:
myForm.CancelButton = btnCancel
On the other hand if you open the form like
myForm.Show()
you do need to specify the action(s) to take on the close button click event as indicated here, ie:
Private Sub BtnCancelClick(ByVal sender As System.Object, ByVal e As EventArgs) Handles btnCancel.Click
Close()
End Sub
I was having the same issues. As soon as I use My.Settings.Blabla = Blabla.value, it gets saved even if I haven't used My.Settings.Save() which makes My.Settings.Save() completely pointless as far as I can tell.
I ended up taking up Jordell's advice: Don't change "the values" until the user clicks the Save button but it wasn't too clear for me how to go about it.
I ended up using temporary variables in all my settings subs instead of the user My.Settings.UserConfigs. Only when I was in the OK sub did I call
My.Settings.UserConfigSetting = temporary_UserCofigValue
Here is an example from the code I was working on:
Private Sub btnOptionsThemeLB_Back_Update_Click(sender As System.Object, e As System.EventArgs) Handles btnOptionsThemeLB_Back_Update.Click
If (tempOptionsThemeLB_Back = Nothing) Then
tempOptionsThemeLB_Back = Me.btnOptionsThemeLB_Back.BackColor
End If
tempOptionsThemeLB_Back = RGBToColor(txtbOptionsThemeLB_Back_Red.Text, txtbOptionsThemeLB_Back_Green.Text, txtbOptionsThemeLB_Back_Blue.Text, tempOptionsThemeLB_Back)
Me.btnOptionsThemeLB_Back.BackColor = tempOptionsThemeLB_Back
End Sub
And only withing the Ok sub did I call My.Settings.
'Theme Section
My.Settings.colorBtnBack = tempOptionsThemeLB_Back
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