I am trying to use the MouseClick event from the properties of a listView to handle left and right mouse clicks.
Unfortunately the event never seems to fire. (Double clicked on the event to create a property, entered a bit of simple code and placed a breakpoint on the first line). The same is true of several other events listed in the properties (ItemSelectionChanged seems to work but the other events I have tried don't fire.
Here is the code added:
In form.designer.cs:
this.listView1.MouseClick += new System.Windows.Forms.MouseEventHandler(this.listView1_MouseClick);
In form.cs:
private void listView1_MouseClick(object sender, MouseEventArgs e)
{
Some code
}
That method never gets called when I click on the listview. The listview is inside a tab on top of the stack.
I guess I am probably forgetting something very basic but what?
ListView is a bit unusual, its MouseClick event doesn't fire unless you click an item in the view. Workaround is to use the MouseDown or MouseUp event instead. You typically are much more interested in the ItemSelectionChanged event btw. You probably need its HitTest() method to see exactly what was clicked if you use MouseDown/Up.
Related
Good evening. I've looked at everything I can on Google and cannot find what I'm looking for (or I am not searching correctly). Thanks ahead of time for the help.
In XAML, on a ContentControl, I have MouseDoubleClick="ControlClick".
This ContentControl does not have a single mouse click event. So I added one in code. When that single-mouse-click event in code is called, I would like to call the MouseDoubleClick event defined on the ControlConrol in XAML.
In the single-click mouse event, I have the ControlControl object (I'll call it "c"). There is a ContentControl.MouseDoubleClick handler but I do not know how to invoke it.
How may I? Thank you in advance.
First of all, ContentControl does have single mouse button click events: MouseButtonDown and MouseButtonUp, depending when you'd like to handle the action.
Then, to invoke a MouseDoubleClick event in your single click event handler, you'd call the following:
(sender as ContentControl).RaiseEvent(new MouseButtonEventArgs(e.MouseDevice, e.Timestamp, e.ChangedButton) { RoutedEvent = MouseDoubleClickEvent });
where sender is the object and e is the MouseButtonEventArgs e of the single click event.
You must remember that double clicking will now invoke two single click events (which invoke the double clicking in turn) and a double click event, thus the double click event handler will effectively be called trice.
You can protect against this behaviour by checking the TimeStamp property of the MouseButtonEventArgs and ignoring the incoming event in the handler if the timespan between the clicks is too short.
What I'm trying to do is get my winform to display a debug line when ever I click in my winform. However, when I do, nothing happens. I know how to get a button / other click event to happen. But what I need is to be able to click anywhere within my winform.
I've googled this for the past hour but can't see what I'm doing wrong. As far as I'm aware, this code should be correct in detecting a mouse click. This method is held withing the form1.cs class:
private void mouseClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
Trace.WriteLine("Mouse clicked");
}
I've tried setting brake points, but these don't get triggered either. What is it I'm doing wrong?
Sorry for the stupidly newbie question, but I am very new to winform programming.
How to add the EventHandler:
public Form1()
{
InitializeComponent();
// This line should you place in the InitializeComponent() method.
this.MouseClick += mouseClick;
}
Using the editor built-in to Visual Studio:
Go to the properties window (if you don't see it, press Alt + Enter).
Select the events icon (looks like lightning).
Double-click on the empty ComboBox to the right of Click.
You'll be taken to an empty method where you can put your code.
The method itself is correct. I think your actual problem is: you haven't added this method to MouseClick events.
In C# – and most other languages too – event is handled by an event handler. Windows forms and controls have events for all the events happening in your controls, such as OnClick or OnResize.
You can append methods to these events, and the methods will automatically get called when the actual event happens. Simply add the following line to your form's constructor, Form_Load-method, InitializeComponent-method, or such:
this.MouseClick += mouseClick;
Now when ever MouseClick event happens, your method mouseClick will be called automatically.
I would recommend reading Events C# Programming Guide. You need to add an event handler like so:
form1.MouseClick += mouseClick;
I was wonder how can I fire an event when the user double click on my webbrowser component. Since it has no such event how it could be possible...
Thanks in advance
Sounds like a WPF matter :-)
There you would go with an Behaviour attached to the browser. See this link for more information about this approach if you can alter your application (dependends on what you have done yet).
If you can't apply this solution, just bind a event handler to the click event and count click per time with respect to the mouse movement since the last click and if both conditions are true (two clicks in 0.2 secs, mouse hasn't moved more than 2px, for example) execute your double click code. The events you should use are previewMOUSEdown or MOUSEdown, not KEYdown.
// Call this where you want to create the event (let's say on the form load for example).
webBrowser1.DoubleClick += new EventHandler(webBrowser1_DoubleClick);
// This happens when the event is fired (so when you double click on the webbrowser control).
void webBrowser1_DoubleClick(object sender, EventArgs e)
{
// Code
}
Try this.
I don't know why you can't set this event via the designer :(, but this should work.
I wrote a method to handle a comboBox's SelectedIndexChanged event.
In the constructor I populated the comboBox, and this activated my event-handling method. Which I don't want since nobody clicked on the comboBox.
Is there an easy way to get the comboBox not to fire the event unless the user clicked it?
If that is not possible, is there a way to disconnect the event to the method temporarily? Could I just set "my_combo.SelectedIndexChanged = null" and then create a new System.EventHandler?
Or I guess I could create some kind of boolean member variable that I can switch on or off and put a branch check in my method. That seems like a kludge, though.
I have done it a lot number of times.
Solution1: Delete EventHandler from designer. Populate the combobox and then set EventHandler.
Combo1.SelectedIndexChanged += new EventHandler Combo1_SelectedIndexChanged;
But it will work only if you are populating the combobox once.If you are doing it for many number of times, then you may be in a mess.
Solution2: Its my preference and I use it regularily.
Change your selection change event as:
private void cb1_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox cb = (ComboBox)sender;
if(!cb.Focused)
{
return;
}
// Here is your Code for selection change
}
So now the event will be fired only if its in focus. Hope you were looking for the same.
Hope it Helps
Not sure if this is any use now but I found this answer, which seems cleaner to me.
From the MSDN Library - ComboBox.SelectionChangeCommitted Event
"SelectionChangeCommitted is raised only when the user changes the combo box selection. Do not use SelectedIndexChanged or SelectedValueChanged to capture user changes, because those events are also raised when the selection changes programmatically."
You can use both methods You proposed:
use boolean variable
detach event method, populate combobox, attach event method like this
my_combo.SelectedIndexChanged -= my_Combo_SelectedIndexChanged;
populateCombo();
my_combo.SelectedIndexChanged += my_Combo_SelectedIndexChanged;
my_Combo_SelectedIndexChanged is the name of method you attached to the event.
I would use control.ContainsFocus instead of creating other bool. The caveat here is that you have to make sure the user has focus on that control. Either by key or mouse.
if(combo.ContainsFocus){ MyEventLogic();}
Solution: If you're populating combobox with static values only ones, just populate them and after subscribe to event from code. Do not use WinForms Designer to subscribe to it.
If it's not possible during loading can:
a) define a boolean variable bool loading, set it to true before you begin to populate combo with data, and in event handler check
if(loading)
return;
b) Unsubsribe from event:
If subscription was:
comboBox.SelectedIndexChanged += delegate(...);
Unsubscription before you begin load data is:
comboBox.SelectedIndexChanged -= delegate(...);
As loading of data finished, subscribe again.
I have a textbox in a groupbox, both with double click events. When I double click in the textbox both events are triggered.
How do I stop clicks in the textbox from passing through to the groupbox? I've tried putting "e.Handled = true;" at the end of the textbox_DoubleClick event but this makes no difference.
Because WPF uses a "tunneling / bubbling" model of event propagation, most events begin bubbling UP from the bottom of the visual tree. If you want to catch an event on the way down, there are Preview versions of the events that tunnel downwards. For example:
PreviewMouseDoubleClick
Set e.Handled = true in there.
In your GroupBox's DoubleClick event you could check the value of e.OriginalSource and if that value is not the GroupBox, ignore the event
private void TabItem_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
if (e.OriginalSource is GroupBox)
{
// Your code here
}
}
I believe ClickEvents are actually Direct Events, and not Tunneled/Bubbled events, so setting e.Handled in one won't cancel the other.
Per MSDN Site for MouseDoubleClick
Although this routed event seems to follow a bubbling route through an
element tree, it actually is a direct routed event that is raised
along the element tree by each UIElement.
you should handle e.Handled in the PreviewDoubleClick because tunneled events happens before bubbled up ones.
also why would you need to handle that event in both textbox and groupbox ? as it is getting fired in both because 2 separate events are getting fired.