i have small problem with autocomplete option in combobox. Everything is working correct, except that i want to work it diffrent :)
When I start typing in combobox, autusuggest working the way i like :
But when i first open combobox, and then start typing i get something like that:
What's more i can't pick item from autosuggest combobox, only from this list under.
AutocompleteMode is SuggestAppend
I'd like to have autosuggest like on the first picture, and in situations like picture 2, this first combobox list should be closed somehow..
I had the same problem and solved it this way:
private void comboBox_DropDown(object sender, EventArgs e)
{
ComboBox cbo = (ComboBox)sender;
cbo.PreviewKeyDown += new PreviewKeyDownEventHandler(comboBox_PreviewKeyDown);
}
private void comboBox_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
ComboBox cbo = (ComboBox)sender;
cbo.PreviewKeyDown -= comboBox_PreviewKeyDown;
if (cbo.DroppedDown) cbo.Focus();
}
Once the user clicks on the DropDown button PreviewKeyDown event is attached to that ComboBox. When user starts typing, freshly added event is triggered. In that event we check if ComboBox is DroppedDown, if it is, focus that ComboBox. On ComboBox focus DropDown disappeares and that's it.
What about using the DropDown and DropDownClosed events to disable or change the auto-complete mode?
I was having exactly the same problem.
I tried the DropDown and DropDownClosed events to set the AutoCompleteMode property to none and suggest.
In this situation the SelectedIndexChanged event does not get fired after selecting an item with the mouse.
I was using the SelectedValue property in the SelectedIndexChanged event and this property is already changed at the moment the DropDownClosed event is triggered.
In my case I simply called the SelectedIndexChanged method from the DropDownClosed event to solve the problem.
Implement event on ComboBox KeyDown. It should look like this.
void cmbExample_KeyDown(object sender, KeyEventArgs e)
{
if ((sender as ComboBox).DroppedDown)
(sender as ComboBox).DroppedDown = false;
}
Have you tried the other possible values for AutoCompleteMode, which are Append, None, and Suggest? I think that what you are looking for is Suggest instead of AppendSuggest.
Here is some downloadable sample code illustrating the different modes, if you need it.
I also found the default UI implementation distracting as the two dropdowns fight for mouse control.
You want to hide the dropdown list when autocomplete suggestions are shown. There is a windows message that the combobox makes before showing the autocomplete suggestions. I chose to collapse the droplist in response to this message. It requires a small override of the combobox to achieve this:
Public Class Combobox2
Inherits ComboBox
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
If m.Msg = 135 AndAlso DroppedDown Then 'WM_GETDLGCODE
DroppedDown = False
End If
MyBase.WndProc(m)
End Sub
End Class
void cmbExample_KeyDown(object sender, KeyEventArgs e)
{
cmbExample.DroppedDown = false;
}
Related
I have a ComboBox whose DropDownStyle is DropDown, allowing the user to type into it and its AutoCompleteMode is Suggest. The problem is that if the ComboBox is currently open and the user starts typing into it the auxiliary drop-down list appears but clicking on an item from it actually selects the item from the ComboBox's original drop-down list residing under the mouse at the time of click.
I would prefer if while the ComboBox's drop-down list is open the user could not type into it and would like to know if there is a more elegant solution than:
Setting the AutoCompleteMode to None when the ComboBox is open
Possibly changing the DropDownStyle to DropDownList on the OnClick event (haven't tried, but the theory is sound)
Manipulating (or restricting) the entered text while the list is open
Similar
As an option you can handle KeyPress event of the ComboBox and close the dropdown. It keeps the autocomplete menu open, but closes dropdown:
private void comboBox1_KeyPress(object sender, KeyPressEventArgs e)
{
this.comboBox1.DroppedDown = false;
}
As another option, you can handle DropDown and DropDownClosed events of the ComboBox and disable autocomplete in DropDown and enable it again in DropDownClosed event:
private void comboBox1_DropDown(object sender, EventArgs e)
{
this.comboBox1.AutoCompleteMode = AutoCompleteMode.None;
}
private void comboBox1_DropDownClosed(object sender, EventArgs e)
{
this.comboBox1.AutoCompleteMode = AutoCompleteMode.Suggest;
}
You can create a new class deriving from ComboBox and override corresponding OnXXXX methods and put the logic there. This way you encapsulate the fix in the control class instead of handling events in your form and will have a reusable bug-free control and a more clean code.
I am developing a windows forms application and load the list from this code:
private void showList()
{
TeamTableAdapter teamAdapter = new TeamTableAdapter();
lstTeamName.DataSource = teamAdapter.GetTeamsActive();
lstTeamName.DisplayMember = "TeamName";
lstTeamName.ValueMember = "TeamID";
}
I want to enable a button if the user selects one of the items. What event should I put the code into. I the following code but the event seems to fire before the user clicks on the list.
private void lstTeamName_Click(object sender, EventArgs e)
{
if (lstTeamName.SelectedIndex > -1)
btnImportXML.Enabled = true;
}
I moved my code to the SelectedIndexChange event but it still fires before the user selects an item and the selectedIndex is 0.
You dont want to bind to the Click event but to the SelectedIndexChanged event. You should be able to accomplish this by simply double clicking on the Control in designer.
I would agree that you don't want to bind to Click as that will likely fire too early.
I recommend you look into the DropDownStyle property. http://msdn.microsoft.com/en-us/library/system.windows.forms.comboboxstyle(v=vs.110).aspx. If you set that to DropDownList then the SelectedItemChanged will fire and SelectedIndex could be > -1
If you leave it as the default DropDown then you may want to use TextChanged and check the Text property.
I'm having problems with the autocomplete property of a combobox. I want to trigger the SelectionChangeCommited event every time I choose an item using the autocomplete but it's not working. The only way the event is triggered is when I use the mouse click and select an option or when the combobox is focused and I use arrow keys on the keyboard. How do I achieve this behaviour using the autocomplete property?
My combo has these properties set:
AutoCompleteMode = SuggestAppend
AutoCompleteSource = ListItems
FormattingEnabled = True
The items in my combo are set with a datasource.
Any ideas?
Thanks
If you mean that you want it to register a change when you start typing:
Call the SelectionChangeCommited event from the TextChanged event.
If you've never done this, the most basic example I could find was on the .net forums here. Granted, the methods shown there are generalities, but is very simple to understand and apply to your code.
EDIT FIXED (as of most recent comment):
Still tie the events together, but instead of using TextChanged, which would occur ever time you type, use the SelectedIndexChanged, which occurs when you use the mouse to select an auto suggested item.
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
comboBox1_SelectionChangeCommitted(sender, e);
}
you canuse a trick and call comboBox1_SelectionChangeCommitted
in Validated event
when ever text in combobox changes and user leave the combo box it will be fired
private void comboBox1_Validated(object sender, EventArgs e)
{
comboBox1_SelectionChangeCommitted(sender, e);
}
When I am having a value item selected in my WPf DropDown Combo Box then navigating using keys Left and right arrow keys result in firing of selected changed event for each item.
How to overcome this problem
The most easy and suitable way I found to overcome this problem is as follows:
rather than using SelectedIndexChanged event I used on DropDownClosed event and all code that is wriiten earlier inside selected index changed moved to this event under a if condition that checks whether a item is selected or not. Like this.
private void OnCmbOperatorsListDropDownClosed(object sender, EventArgs e)
{
if (cmbOperatorsList.SelectedIndex != -1)
InsertText(cmbOperatorsList.SelectedValue.ToString());
//Do whatever u want with selected item
}
So in this way when i navigate through Arrow keys SelectedIndexChagned event will not fired or since i haven't used that event so it will not create any problem.
As per my knowledge this is not possible straight away. I could have implemented this in a kind of "selection simulated" manner.
Handle arrow keys on combobox dropdown in PreviewKeyDown event by setting e.Handled = true. So that usual navigation based selection wont happen.
Inthese handlers based on Keys, change the Background and Foreground of the previous or next item from the drop down list so that it will look as if its selected and highlighted.
Then perform selection of the item which curently has the "simulated selection background - foreground" when dropdown closes. After dropdown closure, revert the background and foreground style.
But thats just my way of doing it.
You can use the PreviewKeyDown event like
private void combo_PreviewKeyDown(object sender, KeyEventArgs e)
{
if (e.Key.Equals(Key.Left) || (e.Key.Equals(Key.Right)))
{
((ComboBox)sender).SelectionChanged -= combo_SelectionChanged;
}
}
and if u want to attach that event you can add this PreviewMouseDown event.
This is what i tried and may not be a proper method of doing such cases
I have a combobox on the winforms. On Enter even I open it:
cbo.DroppedDown = true;
But if I do that the combo opens and closes immediately. What am I doing wrong?
The reason why I use this event is I need to open combo on Tab, when user click tab on the previous control, this combo opens properly. But if user clicks the combo it opens and closes. How to do that properly?
Thanks
I tried it just like this:
private void comboBox1_enter(object sender, EventArgs e)
{
comboBox1.DroppedDown = true;
}
no changes to mouseup or timers. it behaved just as expected. Whether I selected the comboBox with a mouse click or tabbed into it the drop down list appeared and stayed open until I selected something.
I would look to see if there is something else pulling focus off the box.
The reason you are having this problem is because the mouseup event occurs after the enter event and the default window procedure is closing the combobox.
In the enter you could check the mouse button status and if the button is down, do not open the combo. Then have another event handler for the mouseup event to open the combo.
Another option is to set a timer for a few milliseconds, and open the combo when it goes off.
Knowing this is a bit old, but I found that this works well. You can TAB into the combo box and it opens and if you click the arrow it doesn't close back up.
private void ComboBox_Enter(object sender, EventArgs e)
{
if (MouseButtons == MouseButtons.None)
((System.Windows.Forms.ComboBox)sender).DroppedDown = true;
}
Set DroppedDown = true in GotFocus event of the combobox. Otherwise, the dropdown list will show at wrong location.
void cbo_GotFocus(object sender, EventArgs e)
{
ComboBox cbo = sender as ComboBox;
cbo.DroppedDown = true;
}
I think you just need to focus it first before open the comboBox.
cbo.Focus();
cbo.DroppedDown = True
Hope it works for you.