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Cannot keep OnClick event after visibilty change

Just wondering if someone else can recreate this or is it just me :)
Drop a panel on the form
Put a button on the panel
Create click of button "I am Button"
Above works fine
Add onmouseleave to panel set button visible to false
Add onmouseenter to panel set button visible to true
Now if you move mouse in and out of panel the button will become visible false. Pefect.
Now move mouse back intp panel and button becomes visible. Perfect.
Clicking on button now does nothing (Lost on Click Event?)
Breakpoint in onclick never fires.
Is this a concept that cannot be done?
'Update' It wont let me post long comment.
First of all thanks for the quick responses.
I did not include code because this was in a very large project so i recreated it with a brand new app.
C# WinForm with one panel and one button on the panel.
I did not try to click on an invible button. Not only can i see the button but can see it respond to bing clicked.
#steve. Good point, The button is well inside of the panel but i see where you are going. I just performed a new test.
If i move the mouse in and out of the panel the button will show and hide perfectly.
After this, hitting enter on the button will excute onclick but the mouse will not. (I suppose this has something to do with only one button and it is default.)
What prompts the mouse to not fire the click event is beyond me.
Very Strange.
What i am trying to achieve:
An area on the screen that when the mouse enters this area a group of buttons appear so they can be used.
when the mouse leaves this area the buttons will dissapear. As my original post stated button works fine if visiblity does not change.

I suppose the your code has the following problem:
You receive the mouseenter event on the panel and you make the button
visible
You move the mouse over the button
This last action triggers the mouseleave event on the panel.
As a consequence your button becomes invisible.
But making the button invisible triggers a mouseenter over the panel and in a blink the button is again visible and causing a mouseleave on the panel.
An infinite loop between these two events starts.
So the click event is not lost, simply it will never trigger because the form engine is busy hiding and showing the button control.
I have reproduced the situation and fixed it adding an event handler for the MouseMove event. In this event I set a variable to block the infinite loop between the two events...
This is my example to adapt to your real code, try it in LinqPad
public class Form1 : Form
{
Button b1 = new Button();
Panel p1 = new Panel();
bool stillOnPanel = false;
public Form1()
{
b1.Text = "ClickMe";
b1.Click += onClick;
b1.Visible = false;
p1.MouseEnter += onEnter;
p1.MouseLeave += onLeave;
p1.MouseMove += onMove;
p1.BorderStyle = BorderStyle.FixedSingle;
p1.Size = new Size(150,100);
this.Controls.Add(p1);
p1.Controls.Add(b1);
}
void onClick(object sender, EventArgs e)
{
Console.WriteLine("Clicked");
}
void onMove(object sender, MouseEventArgs e)
{
//Check if we are still over the panel area
stillOnPanel = b1.ClientRectangle.Contains(p1.PointToClient(Cursor.Position));
}
void onEnter(object sender, EventArgs e)
{
if (!b1.Visible)
{
b1.Visible = true;
}
}
void onLeave(object sender, EventArgs e)
{
// Do not hide the button if we are over it, let it click....
if (b1.Visible && !stillOnPanel)
{
b1.Visible = false;
}
}
}

Using Mouse.Capture to detect a click outside of a given control

I have a TextBox in a WPF project where I am trying to detect a mouse click anywhere on the Application other than in the TextBox.
Here is the code that I have so far.
System.Windows.Input.MouseButtonEventHandler clickOutsideHandler;
public MyClass() {
clickOutsideHandler = new System.Windows.Input.MouseButtonEventHandler(HandleClickOutsideOfControl);
}
private void StartCapture() {
System.Windows.Input.Mouse.Capture(TextBox1, System.Windows.Input.CaptureMode.SubTree);
AddHandler(System.Windows.Input.Mouse.PreviewMouseDownOutsideCapturedElementEvent, clickOutsideHandler, true);
}
private void HandleClickOutsideOfControl(object sender, System.Windows.Input.MouseButtonEventArgs e) {
ReleaseMouseCapture();
RemoveHandler(System.Windows.Input.Mouse.PreviewMouseDownOutsideCapturedElementEvent, clickOutsideHandler);
}
The problem I'm having is that the event handler never gets called. I've tried capturing the return value of the Capture() function, but it shows as true. Can anyone show me what I'm doing wrong?

You could instead use LostFocus / LostKeyboardFocus but there has to be another element on the window that can get focus.
Second approach that does more what you what exactly ( yet doesn't make total sense) would be to attach to the global mouse down. Intercept every mouse click to WPF application
then on that one do a hittest and determine what is underneath.https://msdn.microsoft.com/en-us/library/ms608753(v=vs.110).aspx

Prevent Windows firing events during long touch of a button

WinForms application.
User touches a button (touchscreen) that causes authentication and the screen (A) is changed to another screen (B). If user continues to hold the finger on the screen (just for a second) the screen B has a button that overlaps with the button on screen (A) and the button on screen B inadvertently gets a touch and invokes an action that is not supposed to happen...
How do I do to prevent this from happening?

That is weird behavior. I do not have a touch device to test this but in a regular scenario the click only triggers when the button is pressed and then released while the button is still in focus. If you press the button and do not release, the click event will not fire.
Anyhow perhaps what you can do is only show screen B when the button has been pressed and then it has lost focus. Like this:
private bool buttonIsClicked = false;
private void button1_Click(object sender, EventArgs e)
{
this.buttonIsClicked = true;
}
private void button1_Leave(object sender, EventArgs e)
{
if (this.buttonIsClicked)
{
this.buttonIsClicked = !this.buttonIsClicked;
// show screen B
}
}
Please use a variable like I have used buttonIsClicked so the code in Leave event handler is not executed every time the button loses focus even if it is not clicked.

How to capture mouse wheel on panel?

How to capture mouse wheel on panel in C#?
I'm using WinForms
EDIT:
I try to do it on PictureBox now.
My code:
this.pictureBox1.MouseClick += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseClick);
this.pictureBox1.MouseWheel += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseClick);
private void pictureBox1_MouseClick(object sender, MouseEventArgs e)
{
MessageBox.Show("Click");
}
Clicking works. Wheelling doesn't.
Why?

If you can't see the "MouseWheel" event on a component, then you need to create it manually. Also, we need to focus that component, otherwise the "MouseWheel" event will not work for that component. I will show you how to create a "MouseWheel" event for "pictureBox1" and how it works.
INSIDE THE CONSTRUCTOR, create a mousewheel event on that component.
InitializeComponent();
this.pictureBox1.MouseWheel += pictureBox1_MouseWheel;
CREATE THE FUNCTION manually. According to my example, call it "pictureBox1_MouseWheel"
private void pictureBox1_MouseWheel(object sender, MouseEventArgs e)
{
//you can do anything here
}
CREATE a MouseHover event on that component (Go to properties in PicureBox1, select event, locate "MouseHover" and double-click the "MouseHover" event).
CALL "Focus()"; method inside that MouseHover event.
pictureBox1.Focus();
Now run the program.

Windows sends the WM_MOUSEWHEEL message to the control that has the focus. That won't be Panel, it is not a control that can get the focus. As soon as you put a control on the panel, say a button, then the button gets the focus and the message.
The button however has no use for the message, it's got nothing to scroll. Windows notices this and sends the message to the parent. That's the panel, now it will scroll.
You'll find code for a custom panel that can get the focus in this answer.
UPDATE: note that this behavior has changed in Windows 10. The new "Scroll inactive windows when I hover over them" option is turned on by default. The makes the mouse wheel behavior more consistent with the way it works in a browser or, say, an Office program. In this specific case the picturebox now will get the event. Watch out for this.

To wire it up manually...
this.panel1.MouseWheel += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseWheel);
private void panel1_MouseWheel(object sender, System.Windows.Forms.MouseEventArgs e)
{
///process mouse event
}
Easier method is in visual studio click on panel, goto properties viewpanel, select events, locate and double click the "mousewheel" event.

In Winforms, this is achieved using the Control.MouseWheel event

Getting mousewheel events is tricky. The easiest way is using
this.MouseWheel += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseWheel);
instead of
this.panel1.MouseWheel += new System.Windows.Forms.MouseEventHandler(this.panel1_MouseWheel);
This way the form gets the event instead of control. This way is easy but has one problem: you can use only one mousewheel event in your form.
If you have more than one control to get mousewheel event the best way is This answer by "Shehan Silva - weltZ"

How to stop textbox leave event firing on form close

using c# winforms vs2008
I've got a textbox on a form with a method being called from the textBox1_Leave event. The method takes the contents of the textbox in question and populates other textboxes based on the contents.
My problem is that is the user has focus on the text box then clicks the button to close the form (calling this.close) then the form does not close because the textbox leave event gets fired.
If the textbox does not have focus on form close then the form closes fine.
If however a user closes the form by clicking the little X close icon in the top corner the it closes fine all the time with out the textbox leave event being fired.
How can I duplicate the X close functionality so that I can always close the form without the textbox leave event being fired?

The simplest solution is going to be to check which control is actually focused before doing your post-processing - but you can't do it in the Leave handler, because the focus will still be on the text box at that point.
Instead, you need to move your logic to the LostFocus event, which is not in the designer. You'll have to wire it up at runtime:
public class Form1 : Form
{
public Form1()
{
InitializeComponent();
textBox1.LostFocus += new EventHandler(textBox1_LostFocus);
}
private void textBox1_LostFocus(object sender, EventArgs e)
{
if (closeButton.Focused)
return;
// Update the other text boxes here
}
}
The LostFocus event happens to fire after the new control receives focus.
Clarification - you might find that it works by putting this logic in the Leave event - if the focus is changed by the mouse. If the keyboard is used instead, you'll get the wrong behaviour. LostFocus is reliable in both cases - the focused control will always be the "new" control. This is documented on MSDN: Order of Events in Windows Forms.
Incidentally, the reason why you're not having this problem with the "red X" is that the X is not actually a control that can receive focus, it's part of the window. When the user clicks that, it's not causing the text box to lose focus, and therefore isn't causing the Leave event to fire.

Another approach:
Use the textbox's validating event instead of it's leave event, then change the button's CausesValidation property to false. You will also have to set the textbox to not cause validation in the button's click event so the validating event will not fire when the form is closing (thanks to #Powerlord for pointing this out).
private void button1_Click(object sender, EventArgs e)
{
this.textBox1.CausesValidation = false;
this.Close();
}

You could also handle the FormClosing event and make sure the e.Cancel argument does not get set to true by the validating events on the other controls on the form. I think they will be fired off before the FormClosing event.
private void MainForm_FormClosing(object sender, FormClosingEventArgs e)
{
if (e.CloseReason == CloseReason.UserClosing)
{
e.Cancel = false;
return;
}
}

you can check to see which control has just got focus.
private void textBox1_Leave(object sender, EventArgs e)
{
if (btnClose.Focused)
return;
// go from here
}

Just check if the form owning the textbox is disposing? If it's getting closed, it's disposing. If it's disposing you could simply end the pesky 'leave' event without doing anything. I didn't check it and forgive me, I'm choked on a project of my own so and I was searching myself, so I don't think I'll have time for that.
private void GuiltyTextBox_Leave(object sender, EventArgs e) {
Form formOwningTheTextBox=(Form)((Control)sender).TopLevelControl;
if (formOwningTheTextBox.Disposing || formOwningTheTextBox.IsDisposed) return;
.......
}
I just believe this is going to work with minimum effort and wanted to send a quick answer before I resume searching my own answer.

Write Following line of code in text box leave event on top
if me.closing then
return
end if