I'm trying to make a custom User Control with multiple controls inside (for this example, a Picture box and a label) and I want them all to respond to the same event that I make on the form where I'm using it, all th objects would be:
UserControl1
pictureBox1
label1
However, when i make the (click) event on the form where I wanna use (Form1) the event only applies to the background (userCoontrol1), and therefore it will not work if I click the Picturebox or label, how could I make it that the event applies to every control inside?
I have tried making a click event for userControl1 and applying the same to the others and that works, but I need to change the behavior from the parent which is why this doesn't work, and I'm not sure how I can override this.
Taking into account your comment... One method might be the following
link click event of usercontrol to form1, in form1 code. lets say your function in form1 is called myButton_Click.
UserControl1.Click += new System.EventHandler(myButton_Click);
Then within UserControl1, create an on-click event (lets say "Control_Click") that simply invokes the UserControl1.Click eventhandler.
private void Control_Click(object sender, EventArgs e)
{
Click?.Invoke(this, new EventArgs());
}
Finally link each control's click in usercontrol to that Control_Click event within the usercontrol's constructor
picturebox1.Click += new System.EventHandler(Control_Click);
label1.Click += new System.EventHandler(Control_Click);
Related
do you know a "simple" way to detect when a user control loses focus?
I am creating a console output inspired by Visual Studio.
Visual Studio console output collapses when I click anywhere.
Obviously in my application if I click on a Panel (which has no focus) I do not receive any events.
I had thought about using the mouse_down event on the application, but I would have to do an evaluation with every click!
Do you know any way to know when you click out of your control?
UserControl has a LostFocus event. In the code behind of your UserControl you can simply add an event handler.
public partial class MainView : UserControl
{
public MainView()
{
InitializeComponent();
LostFocus += OnFocusLost;
}
private void OnFocusLost(object sender, RoutedEventArgs e)
{
// Do something here.
}
}
If you are referencing it from another class then you can create an event handler on that class and subscribe to the event from the UserControl.
UserControl control = new UserControl();
control.LostFocus += OnFocusLost;
With that being said, if you have a TextBox or some other control inside of the UserControl then the UserControl will lose focus every time a TextBox gets the focus so you will most likely need to write a method to determine if any of the elements inside the UserControl have focus.
I have an app that uses a side menu, and for each button (there are 3) on the left side menu, it changes the pages shown.
I tried doing it with multiple panels, but it's a nightmare to maintain in designer, and it's probably not a very good programming habit, I expect.
So I search and found what seemed to be a great idea: UserControl.
But as usual, it's not that simple (for a badly self-taught guy like me)
The general flow of the program is as follows:
a Btn_uc1_Check button that gathers informations and displays them in a uc1_ListView,
a Btn_uc2_Seek button that gathers informations on the net based on the uc1_ListView , and displays them on uc2_ListView,
a Btn_uc3_compile that compiles the info from uc2_ListView into a file,
a Clear button that clears the ListView depending on the UserControl on screen.
Now to the problem:
How on earth do I gain access to a ListView located in a UserControl to be able to read, clear, and add items from the MainFrom or from another UserControl?
I searched and honestly found nothing corresponding to what I needed?
Quite many questions.
You can gain access to any controls in UC. Just change the property "Modifiers" of the ListView in your UC to "Public".
Set that method to public. Do not use keyword "static". Each control
in your form is an instance of a class, not a static class actually. In the main form, create a button and double click on it in VS designer. A method will automatically generated, something like private void button1_Click. When the button is clicked, all of the code lines in button1_Click will run.
Create a public event handler of your user control, then pass the method in main to the handler.
So the UC class will be similar to this:
public event EventHandler button_UC_Click_handler;
public UserControl1()
{
InitializeComponent();
}
private void button_UC_Click(object sender, EventArgs e)
{
button_UC_Click_handler.Invoke(sender, e);
}
In main form:
public MainForm()
{
InitializeComponent();
userControl11.button_UC_Click_handler += UserControl11_button_UC_Click_handler;
}
private void UserControl11_button_UC_Click_handler(object sender, EventArgs e)
{
MessageBox.Show("You have clicked it!");
}
Good luck!
This must have been asked before, but I am fairly new and don't quite know how to express myself...
1) I have a UserControl that basically acts as a toolbar. I re-use the toolbar in each window, hence the need for a uc.
2) The toolbar is filled with buttons
3) the usercontrol doesn't act on the button (no code), but it should pass the event back to the parent window so the code in the parent window fires up.
How can I do this? Is this a routed event? any sample code in vb.net would be appreciated!
On you user control, you need events that you can fire when the buttons are clicked. Then in your form, you handle the events just like you do for every other control. IE:
public event Button1_ClickedEventHandler Button1_Clicked;
public delegate void Button1_ClickedEventHandler(object sender);
private void Button1_Click(object sender, EventArgs e)
{
if (Button1_Clicked != null) {
Button1_Clicked(this);
}
}
You can call the event whatever you want and pass whatever you want. Here you will notice I am NOT sending the button but THIS, which in this case should be the User Control.
I have a UserControlwhich contains some inner controls inside it. something like this:
Now when I use it in my project, I want every point of my control raise the same click event if clicked, just like other controls.
but the problem is: my handler in another project, handles click events just when I click somewhere on the background, not on the button1 or label1.
I can solve it by setting every event in inner controls raise another event for the main control, but it is a bit odd.
How can I make the inner controls don't cover the main control's events?
I'd suggest leveraging the UserControls Load event to iterate over all sub controls in your project and add a handler programmatically for each MouseMoved event. This would be robust enough to handle any new sub controls added. E.g;
private void UserControl1_Load(object sender, EventArgs e)
{
foreach (Control c in Controls)
{
c.MouseMove += Control_Move;
}
}
protected void Control_Move(object sender, MouseEventArgs e)
{
// do stuff here
}
And don't forget to hook your UserControl's MouseMove event to the same Control_Move method
I did something like this in Delphi. The trick was to not add a label, but add a sub class of a label, button, etc, that calls the parents events on the event.
The sub class just overrides Click, Move etc and calls parent. Simple, and saves lots of time if you have a lot of these.
I am currently developing a Windows app with several forms. I use Form_Shown in one of those forms to execute some code to initialize (refresh) the form before showing it.
In Form.Shown Event on MSDN, it states that the event is raised only the first time the form is shown. However, I want to be able to execute code to initialize my form every time that I call Form.Show() in some of the forms. Here's an example.
From a form named Game. Contains an event handler Game_Shown and a button that when clicked shows a form named Menu:
private void btnMenu_Click(object sender, EventArgs e)
{
this.Hide();
Formulaires.formMenu.Show();
}
private void Game_Shown(object sender, EventArgs e)
{
Code here...
this.Refresh();
}
From the form named Menu. Contains a button that when clicked shows the form named Game:
private void lblGame_Click(object sender, EventArgs e)
{
this.Hide();
Formulaires.formGame.Show();
}
It is behaving by design.
From the docs:
The Shown event occurs whenever the form is first shown.
Also, you should not handle the Shown event in your class, rather you should override OnShown.
To achieve what you want, you might try overriding the OnVisibleChanged method. Inside the method, if the form is visible, then execute your code.
Like the Shown event, you should not handle it in your form class, instead override the appropriate method:
From the docs:
The OnVisibleChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.
What you want requires some detailed knowledge about which event happens when in the WinForm lifecycle. That may be documented somewhere, I don't know.
This is how I would find out:
create a small test project with 2 forms (Main and helper)
add the show and hide buttons and make sure it works.
Add Debug.Print("EventName") to all the candidate events of the helper form.
Look at the log in the output window and pick your event.
Candidate events would be FormClosing, FormClosed, (De)Activated, Enter, Leave, Load, ... go through the list.
When you find the right one, please post it here in an answer.