I have a UserControl (let's call it "PresentationCell") which contains a label, and an PictureBox.
In another control, which is using this PresentationCell, I have added an event
presentationCell.GotFocus += OnFocus;
private void OnFocus(object sender, EventArgs e)
{
if (sender is PresentationCell current)
current.BackColor = Color.Azure;
}
This will not be fired, if I click / focus on the Label or PictureBox that is within the PresentationCell.
How can I make it fire, when just something within the PresentationCell is in focus?
The problem here is, that the Label and PictureBox controls aren't selectable controls, so they aren't able to receive focus from mouse clicks.
What you could to instead, is to handle the mouse click event and check if you have hit the PresentationCell. If the PresentationCell is hit you can programatically set the focus like so:
hitPresentationCell.Focus();
This will then fire the GotFocus event.
In your OnFocus method you will have to switch the focus to another control or the event will fire endlessly.
I have a WindowForm and some controls on it.
My point is that when I click button "?" on top-right of the datagridview, it will show a picture box and when I click outside the pictureBox, it must invisible.
My MainForm
MyPictureBox
I have searched some topics on this site, but some dont work, some work partly. Like
this.
I also tried:
void pictureBox1_LostFocus(object sender, EventArgs e)
{
if (pictureBox1.Visible)
pictureBox1.Visible = false;
}
But when I click on button2, button3, ... The pictureBox wasn't invisible.
Any solution will be highly appreciated.
I think your pictureBox1 isn't losing focus, cause it never actually GOT focused. Set it to be focused after making it visible.
Oh, I have encountered this before...
I was making a Label that you could double click and it would allow you to edit the Label.Text, like a TextBox. However, I was having problems hooking into the events to know when the user had clicked off the Control and wished to stop editing. I tried Control.LostFocus, and Control.Leave, but nothing. I even got frustrated/desperate and tried some silly ones like Control.Invalidated.
What I ended up having to do was subscribe to the Click event of the Form/Container/Control behind it.
However, putting the responsibility of wiring up this event into the Form that wants to use it is poor design. What you can do, however is to make the constructor to Control class require a reference to the owner/parent/container as a parameter. That way, the requirements are not hidden, they must be satisfied before you can get a object instance, and the control can wired up to the Form.Click within itself, where that logic belongs.
private Form owner;
public EditLabel(Form Owner)
{
this.owner = Owner;
owner.Click += EndEditing;
}
Add this method in designer.cs:
pictureBoxEvent this.MouseLeave += new EventHandler(pictureBox_MouseLeave);
Add this code in cs file:
private void pictureBox_MouseLeave(object sender, EventArgs e)
{
pictureBox1.Visible = false;
}
I'm creating a custom dropdown box, and I want to register when the mouse is clicked outside the dropdown box, in order to hide it. Is it possible to detect a click outside a control? or should I make some mechanism on the containing form and check for mouseclick when any dropdownbox is open?
So I finally understand that you only want it to close when the user clicks outside of it. In that case, the Leave event should work just fine... For some reason, I got the impression you wanted it to close whenever they moved the mouse outside of your custom dropdown. The Leave event is raised whenever your control loses the focus, and if the user clicks on something else, it will certainly lose focus as the thing they clicked on gains the focus.
The documentation also says that this event cascades up and down the control chain as necessary:
The Enter and Leave events are hierarchical and will cascade up and down the parent chain until the appropriate control is reached. For example, assume you have a Form with two GroupBox controls, and each GroupBox control has one TextBox control. When the caret is moved from one TextBox to the other, the Leave event is raised for the TextBox and GroupBox, and the Enter event is raised for the other GroupBox and TextBox.
Overriding your UserControl's OnLeave method is the best way to handle this:
protected override void OnLeave(EventArgs e)
{
// Call the base class
base.OnLeave(e);
// When this control loses the focus, close it
this.Hide();
}
And then for testing purposes, I created a form that shows the drop-down UserControl on command:
public partial class Form1 : Form
{
private UserControl1 customDropDown;
public Form1()
{
InitializeComponent();
// Create the user control
customDropDown = new UserControl1();
// Add it to the form's Controls collection
Controls.Add(customDropDown);
customDropDown.Hide();
}
private void button1_Click(object sender, EventArgs e)
{
// Display the user control
customDropDown.Show();
customDropDown.BringToFront(); // display in front of other controls
customDropDown.Select(); // make sure it gets the focus
}
}
Everything works perfectly with the above code, except for one thing: if the user clicks on a blank area of the form, the UserControl doesn't close. Hmm, why not? Well, because the form itself doesn't want the focus. Only controls can get the focus, and we didn't click on a control. And because nothing else stole the focus, the Leave event never got raised, meaning that the UserControl didn't know it was supposed to close itself.
If you need the UserControl to close itself when the user clicks on a blank area in the form, you need some special case handling for that. Since you say that you're only concerned about clicks, you can just handle the Click event for the form, and set the focus to a different control:
protected override void OnClick(EventArgs e)
{
// Call the base class
base.OnClick(e);
// See if our custom drop-down is visible
if (customDropDown.Visible)
{
// Set the focus to a different control on the form,
// which will force the drop-down to close
this.SelectNextControl(customDropDown, true, true, true, true);
}
}
Yes, this last part feels like a hack. The better solution, as others have mentioned, is to use the SetCapture function to instruct Windows to capture the mouse over your UserControl's window. The control's Capture property provides an even simpler way to do the same thing.
Technically, you'll need to p/invoke SetCapture() in order to receive click events that happen outside of your control.
But in your case, handling the Leave event, as #Martin suggests, should be sufficient.
EDIT: While looking for an usage example for SetCapture(), I came across the Control.Capture property, of which I was not aware. Using that property means you won't have to p/invoke anything, which is always a good thing in my book.
So, you'll have to set Capture to true when showing the dropdown, then determine if the mouse pointer lies inside the control in your click event handler and, if it doesn't, set Capture to false and close the dropdown.
UPDATE:
You can also use the Control.Focused property to determine if the control has got or lost focus when using a keyboard or mouse instead of using the Capture with the same example provided in the MSDN Capture page.
Handle the Form's MouseDown event, or override the Form's OnMouseDown
method:
enter code here
And then:
protected override void OnMouseDown(MouseEventArgs e)
{
if (!theListBox.Bounds.Contains(e.Location))
{
theListBox.Visible = false;
}
}
The Contains method old System.Drawing.Rectangle can be used to indicate if
a point is contained inside a rectangle. The Bounds property of a Control is
the outer Rectangle defined by the edges of the Control. The Location
property of the MouseEventArgs is the Point relative to the Control which
received the MouseDown event. The Bounds property of a Control in a Form is
relative to the Form.
You are probably looking for the leave event:
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.leave.aspx
Leave occurs when the input focus leaves the control.
I just wanted to share this. It is probably not a good way of doing it that way, but looks like it works for drop down panel that closes on fake "MouseLeave", I tried to hide it on Panel MouseLeave but it does not work because moving from panel to button leaves the panel because the button is not the panel itself. Probably there is better way of doing this but I am sharing this because I used about 7 hours figuring out how to get it to work. Thanks to #FTheGodfather
But it works only if the mouse moves on the form. If there is a panel this will not work.
private void click_to_show_Panel_button_MouseDown(object sender, MouseEventArgs e)
{
item_panel1.Visible = true; //Menu Panel
}
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (!item_panel1.Bounds.Contains(e.Location))
{
item_panel1.Visible = false; // Menu panel
}
}
I've done this myself, and this is how I did it.
When the drop down is opened, register a click event on the control's parent form:
this.Form.Click += new EventHandler(CloseDropDown);
But this only takes you half the way. You probably want your drop down to close also when the current window gets deactivated. The most reliable way of detecting this has for me been through a timer that checks which window is currently active:
[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern IntPtr GetForegroundWindow();
and
var timer = new Timer();
timer.Interval = 100;
timer.Tick += (sender, args) =>
{
IntPtr f = GetForegroundWindow();
if (this.Form == null || f != this.Form.Handle)
{
CloseDropDown();
}
};
You should of course only let the timer run when the drop down is visible. Also, there's probably a few other events on the parent form you'd want to register when the drop down is opened:
this.Form.LocationChanged += new EventHandler(CloseDropDown);
this.Form.SizeChanged += new EventHandler(CloseDropDown);
Just don't forget to unregister all these events in the CloseDropDown method :)
EDIT:
I forgot, you should also register the Leave event on you control to see if another control gets activated/clicked:
this.Leave += new EventHandler(CloseDropDown);
I think I've got it now, this should cover all bases. Let me know if I'm missing something.
If you have Form, you can simply use Deactivate event just like this :
protected override void OnDeactivate(EventArgs e)
{
this.Dispose();
}
How to change dropdown button in a ComboBox control (C#, Windows Forms)? I have a custom button, and I want to use it in the ComboBox instead of the default dropdown button.
I think Hans Passant solution is the way...
From here:
http://social.msdn.microsoft.com/forums/en-US/winformsdesigner/thread/5d65f987-834c-465f-a944-622831d4cfb0
You can create a UserControl, drag a
ComboBox and a Button onto it, make
the Button right over the ComboBox's
arrow button to make the arrow button
invisible, handle the Button's Paint
event to draw an arrow on it, this can
be done by calling
ComboBoxRenderer.DrawDropDownButton()
method (Notice: this method has a
limit, it needs the visual style being
enabled on the OS) or by drawing an
icon on it, or just drawing a small
triangle on it.
Then handle the Click event of the button to show the ComboBox's
DropDown, this can be done by
something like this
private void button1_Click(object sender, EventArgs e)
{
this.comboBox1.DroppedDown = true;
}
I have an app with a custom window (transparency and no borders). I made a header with a dragmove behavior on left mouse button down. This allows me to drag the window to the top so it maximizes. Now I want to write the code so that when I click the header and drag it, it restores the windowstate to normal...
Is there a click & drag event handler, or another way?
EDIT: Platform C#, in WPF
You need to use Window.StateChanged Event
The best way to handle Maximalization and Minimalization is to manipulate WindowState Property. It saves the Window.RestoreBounds property with previous size. If you need more sophisticated solution
here is an example
Ps. Similar to Win 7 feature. Maybe there is no need to do so? :)
Edit: in UIElement there is MoveMove event
private void Window_MouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed)
{
MainWindow1.WindowState = WindowState.Normal;
}
}
this is a bit messy since event is going to fire everytime you move it