Is it possible that in a ListView whenever an Item has been selected (e.g mouse 1 left click or Key down or key up, left right) that item gets activated (Like when you hit enter or double click!). What event or properties of ListView will do this, if any?
UPDATE
I found out it will work if ListView.Activation is set to OneClick but thi is only for the mouse, I want the same with keyboard arrows too.
You can do that by listening the the ItemSelectionChanged event and simply calling the code that runs whenever an item is double-clicked.
Alternatively you can call ItemActivate event that fires when an item is double-clicked using this bit of code, although I'd recommend the first method:
private void ListView1_ItemSelectionChanged(Object sender, ListViewItemSelectionChangedEventArgs e)
{
ListView1_ItemActivate(sender, e);
}
You, have mouseclick and mousedoubleclick events in the listview control for this purpose.
Implement the following events with whatever you want your listview to do.
KeyDown , KeyUp, KeyPress, MouseDown, MouseUp, MousePress, MouseHover, MouseEnter, MouseClick, MouseDoubleClick
those are only a few select examples.
Lets say your listview is named listView1
to Subscribe to one of the events, do this
private void Form1_Load(object sender, EventArgs e)
{
listView1.KeyDown += new KeyEventHandler(listView1_KeyDown);
}
void listView1_KeyDown(object sender, KeyEventArgs e)
{
throw new NotImplementedException();
}
Enter your content at the throw statement
Related
I have a WinForm which contains a multitude of controls interdependent on each other for their visibility and content.
I have a pair of radio buttons, controlling a combobox's (ComboBoxA) enable/disable flag and content. The selection on this combobox controls the visibility of a checkbox. The checking of this checkbox controls another combobox's (ComboBoxB) visibility and content. Business requirements are quite complicated around these controls. As a result, I require the ability to fire of the events programmatically and through user action, doing different things in each case.
In the checkbox's case, I check it programmatically while loading data (if needed), which fires the CheckedChanged event which in turn does additional action controlling ComboBoxB. The code for this is pretty vanilla, nothing special, but my question is more theoretical than practical. Please keep reading.
Due to this requirement, I need a way to distinguish between programmatic checking and user action. I tried using the Click event and CheckedChanged event, setting a flag in the click event, signifying user action. Unfortunately, the CheckedChanged event fires before the Click event, dead-ending this trick.
Now, I tried using the MouseDown event to capture user action. But funnily enough, once the event fires, checkbox remains unchecked and the CheckedChanged event doesnt fire.
Now, I have managed to use a flag in the code to determine programmatic checking and use that to distinguish between the two, but I was curious as to why the MouseDown event didnt allow the checkbox to be checked. Any ideas? I searched online but either I didnt do a thorough job of it, or google is not returning the right results for me. I apologize if anybody is actually able to find a google result for this problem.
It's something else in your code, not the MouseDown event that's preventing the CheckChanged to be fired.
Here is how I know this:
I've added a checkbox and a button to an empty form, and added event handlers to Click on the button, and on the checkbox CheckedChanged, KeyDown and MouseDown events. I've also added to the form a string variable called LastEventRaised, and in the CheckedChanged I've simply shown a MessageBox:
string LastEventRaised = string.Empty;
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
MessageBox.Show("Checked changed " + LastEventRaised);
LastEventRaised = string.Empty;
}
private void checkBox1_KeyDown(object sender, KeyEventArgs e)
{
LastEventRaised = "KeyDown";
}
private void checkBox1_MouseDown(object sender, MouseEventArgs e)
{
LastEventRaised = "MouseDown";
}
private void button1_Click(object sender, EventArgs e)
{
LastEventRaised = "programmatically";
checkBox1.Checked = !checkBox1.Checked;
}
Each time the message box popped up I've got the correct message.
I have a Winforms c# form with some comboBoxes , cancel and save buttons that work fine.
I now need to capture when the user has finished entering text into a comboBox.
I add an empty ( for now) lostFocus (or Leave) event to the combbox , which triggers fine. However if the cause of that event was a cancel or save button press , the corresponding event is no longer triggered. These buttons still work fine if pressed at other times.
Should these two event be firing in sequence or is there some better way to capture completed text entry?
The Leave and/or LoseFocus events do not get triggered because you do not leave the combobox and because it doesn't lose focus when you press Enter or Escape.
Therefore the best way is to add the function you are triggering in the LoseFocus event, also to the Button click events of the Cancel- and the Accept-Buttons.
Adding a call to the leave event itself: comboBox1.Leave(null, null); would be the simplest way.
To make sure that the function is called only once, I check who has focus in the ButtonClick events:
private void acceptButton_Click(object sender, EventArgs e)
{
if (comboBox1.ContainsFocus) comboBox1_Leave(acceptButton, null);
// do accept stuff here..
}
private void cancelButton_Click(object sender, EventArgs e)
{
if (comboBox1.ContainsFocus) comboBox1_Leave(cancelButton, null);
// do cancel stuff here..
}
private void comboBox1_Leave(object sender, EventArgs e)
{
// do leave stuff here..
Console.WriteLine(sender);
}
I also pass in the Button so you could check the sender to see how the Leave was triggered..
I'm answering my own question here as I feel it might be useful to other newbies.
The breakpoint I had set in my empty lostFocus event was stopping button click event from occurring. When I removed the breakpoint the problem went away.
However when I added code to my lostFocus event, a form redraw was sometimes moving the buttons and preventing their events from firing. To solve this problem I adapted TaWs very useful answer and fired the button event from within the lostFocus event.
private void comboBox1_LostFocus(object sender, EventArgs e)
{
bool saving = btnSave.ContainsFocus;
// form redraw stuff here..
if (saving)
btnSave_Click(btnSave, null);
}
I have a DataGridViewComboCell in a DataGridView.
I need to know when the user has clicked one of the selections in that combo cell.
I can't find an event that fires when this happens.
For most of the events with names that sound like they will do this, they don't do anything until the user changes focus.
I don't know why Microsoft waits for users to change focus to do something. I certainly don't expect this behavior. The QA staff assigned to me sure doesn't.
I can't believe Clicked() doesn't fire when someone clicks this. Neither does ContentClicked or the other clicked methods.
Here are all the events I've tried: CellContentClick, CellEndEdit, SelectionChanged, Click,
CellStateChanged, CellClick, CellValueChanged.
None of them change until the user changes focus!
Maybe you are looking for the SelectedIndexChanged event of the DataGridViewComboBoxCell. You have to find that event in the DataGridViewComboBoxEditingControl, like this:
//EditingControlShowing event handler for your dataGridView1
private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e){
ComboBox combo = e.Control as ComboBox;
if(dataGridView1.CurrentCell.OwningColumn == column_you_want){
combo.SelectedIndexChanged -= combo_SelectedIndexChanged;
combo.SelectedIndexChanged += combo_SelectedIndexChanged;
}
}
private void combo_SelectedIndexChanged(object sender, EventArgs e){
//....
}
I am having trouble getting my application to work correctly. I am trying to select a row in a datagridview with the mouse. I need to save the index of this row to allow me to navigate around the selected row.
I have been looking at DataGridView.CellMouseClick Event (Link) But I am unable to ensure that the event handler is associated with the CellMouseClick event.
My code for this so far is simple, Im just trying to see if its detecting mouse clicks:
public event DataGridViewCellMouseEventHandler CellMouseClick;
private void DataGridView1_CellMouseClick(Object sender, DataGridViewCellMouseEventArgs e)
{
MessageBox.Show("Mouse clicked in the datagridview!");
}
Can anyone point out where I may be going wrong. Any help would be great!
You need to "wire up" the event.
If your DataGridView is called DataGridView1 then you need the following line of code in either the constructor for your form, the designer (if you add the event handler via the designer) or in the Load event:
DataGridView1.CellMouseClick += DataGridView1_CellMouseClick;
This attaches the event handler in your code to the event.
Your current sample looks like this:
public event DataGridViewCellMouseEventHandler CellMouseClick;
private void DataGridView1_CellMouseClick(Object sender, DataGridViewCellMouseEventArgs e)
{
MessageBox.Show("Mouse clicked in the datagridview!");
}
There is no need to redeclare the event (public event DataGridViewCellMouseEventHandler CellMouseClick;) unless you are building your own user control that will host a DataGridView and you effectively want to "wrap" or "rebroadcast" that event.
using mysql I feed combobox2 with selection of combobox1.It works OK. but the problem is the first select seems does not trigger the eventhandler. the second time I do it it will trigger.
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
comboBox1.SelectedValueChanged += new EventHandler(comboBox1_selectedvaluechanged);
}
private void comboBox1_selectedvaluechanged(object sender, EventArgs e)
{
region = comboBox1.SelectedItem.ToString();
values_to_venue();
db.connection.Close();
}
It's because you're not creating your event handler until the SelectedIndex of the combobox changes. This is fired alongside SelectedValue changes. Create the event handler in the load method ensuring it is there when the first SelectedValue changes. If you put it in the Load make sure you clean it up with -= in the unload. Or, you can just create it in the constructor and then you won't need to remove it.
You do want to set the events in your constructor or load method; also, I think the event you want to use is ComboBox.SelectionChangeCommitted because if the user navigates the DropDown list using the up/down arrows on the keypad, SelectedIndexChanged will fire before the selection is committed - is that what you want??????