I have a ComboBox implemented with an auto-completion system. My ComboBox contains more than 100 items. When users are typing text in, the auto-completion system opens the dropdown list and highlights the most relevant item. Moreover, when the dropdown list is expanded, all items are available (no filters). But the most relevant item is always at the bottom of the dropdown list.
I would like it to be in the middle, if possible. One item can have the same reference but another type than another one, that's why I need to see most of them in my dropdown by placing them in the middle.
Any idea ? It's not really important but kind of useful for them. Thanks !
Update :
Here's my ComboBox with the open dropdown. Sorry about that, I had to blur its elements. As you can see, the user starts writting the reference in the ComboBox. The autocompletion works fine, but the corresponding item is found at the end of the dropdown list (in the red frame), almost out of bounds.
I wish it would be highlighted in the middle of my dropdown list instead of so far below.
Your item search may work well, but your list isn't visually filtered, which means it's size always remains the same.
It's scrolled into view, by the wpf system, but still displaying all other items around the relevant one. The reason why it's at the bottom is because wpf Scrollviewer just finished scrolling the item into view and sees no need to scroll it further into the middle.
You could use the CollectionViewSource class. Why ?
It's simple to use, will keep your viewmodel data as it is, and you would have your relevant completion item at the top. It can be obtained by GetDefaultView(..)
Let's say you have a viewmodel flag "IsHidden", stating that it's content does not match the user input:
ICollectionView cv= CollectionViewSource.GetDefaultView(myComboBox.ItemsSource);
// switch filter on
cv.Filter = obj => (obj as myViewModel).IsHidden == false;
// switch off
cv.Filter = null
Related
I have a view that contains several ComboBox elements. For some reason old data remains from the previous time the view was opened and I would like to reset the combobox elements in the view every time it is opened. Is there a function that could that for me? I want it to be exactly how it is as if I rendered it the first time with the initial items. Would using setSelectedItem(vItem), setSelectedItemId(vItem), setSelectedKey(sKey), setShowSecondaryValues() help? If so, what do these keywords mean (selectedItem, selectedItemID, selectedKey, secondaryValues)?
Unfortunately you do not provide an example. Normally you bind your UI controls against a model, e.g. JSONModel. In this case the items of your ComboBox controls would be taken from the corresponding model. However, you can use method removeAllItems to achieve the desired behaviour.
UPDATE: Obviously the controls are bound and only the selection should be cleared.
Use setSelectedItem with value null to clear the selection. You could also use the binding to set the selected item automatically by using the selectedKey attribute, see example.
I have a VB6 application that has been running for quite sometime. Currently I'm trying to update one of the form that has a combobox 2.0. Because the combobox is populated with hundreds of items - I'm trying to update it so that users are able to click on a look up button next to it, where another window opens up with all the items from the combobox. User will be able to search by keyword and/or select an item and double click on it and have it appear in the combobox. The issue I'm having is with trying to pass no value or "" when CANCEL is clicked. I'm able to pass the value if I in the properties window my STYLE Is set to COMBO rather than list. However, the issue I come across is that with COMBO the value (text) in the combobox sometimes is not aligned properly. Is there a way to pass a "" value to a combobox 2.0 without changing the style to COMBO?
If they hit cancel set the ListIndex of your combo to -1 rather than setting the text property. This is the value for no item being selected.
Friends,
I have a WPF Combobox. When the Combobox is opened, I have the items dynamically generated based upon environment variables. So basically a combobox that is bound to a list that is dynamically changing.
Everything works as expected until I Exit the combobox with the dropdown open to enter another control(another combobox).
When I reopen the first combobox, the items appear to be frozen and no longer bound to the list when INDEED the list is changing and is still bound. Its almost like the binding broke.
When this event occurs, I have attempted to forcefully add items, and that doesn't work either. I can see in the code behind that the combobox now contains the additional items, yet it doesn't appear that contain them in the UI.
What is this black magic? Any way to prevent it? is this some type of Stuck focus issue? Maybe the dropdown isn't re-sizing?
I think i have narrowed it down to the physical dropdown is not re-sizing to the new items.
EDIT*
The controls are dynamically generating, so I have no real hard code to show you other than this.
private void CBControl_DropDownOpened(object sender, EventArgs e)
{
((ComboBox)sender).Items.Add("Option");
}
On this event, I will add an items to the combobox, although the items ARE being added to the list, they are not displayed in the UI.
EDIT 2*
I figured it out, so i have 2 comboboxes, it appears that the 2nd was steeling and holding the focus INSIDE the dropdown. (odd bug)
in order to fix it i needed to release it bu changing the index of the 2nd combo box WHILE it is open.
int sel = ComboBoxTwo.SelectedIndex;
ComboBoxTwo.IsDropDownOpen = true;
ComboBoxTwo.SelectedIndex = -1;
ComboBoxTwo.IsDropDownOpen = true;
ComboBoxTwo.SelectedIndex = sel;
and I had to manage the unintended recursive call.
So, here it is.
You got 2 ComboBoxes. If you Open one then directly click into another, the focus is moved to the second combobox dropdown.
If you make any changes to the first combobox, the changes will not take effect to the style(dropdown resize) UNTIL you release the focus from the 2nd combo box dropdown item. Although the items change will take effect, the resize wont.
to release the focus, you need to open the second combox and change the selected index like so:
int sel = ComboBoxTwo.SelectedIndex;
ComboBoxTwo.IsDropDownOpen = true;
ComboBoxTwo.SelectedIndex = -1;
ComboBoxTwo.IsDropDownOpen = true;
ComboBoxTwo.SelectedIndex = sel;
10 hours of debugging. 5 hours of research. First solution I have found. It may be dirty, but its all I can find.
I have a Source ComboBox to populate source fields (25-30 items) shown below in first page
"A"
"B"
...
"Z"
I have selected last item from ComboBox as shown below
"Z"
and when traversing to the next page after saving, i need to make the source combo selection blank, so i have return the below code to reset the Source combobox to point to first item (to reset the display to start from top of dropdown list for user selection)
// my first value in source List is empty space - “”
sourceComboBox.setValue("");
even if you use below code snippets like
sourceComboBox.getSelectionModel().selectFirst();
sourceComboBox.getItems().clear();
sourceComboBox.getSelectionModel().clearAndSelect(0);
but when i click open the combobox dropdown it still shows dropdown display from bottom as shown below
...
"X"
"Y"
"Z"
I am unable to post images for representing combobox values, so has put in above examples.
This looks like a graphics bug to me or am I doing something wrong?
I have seen similar issue reported in below question but no work around suggested so far
Combobox clearing value issue
If you want to simply "reset" the combo box, I think all you have to do is set the value to null, like so:
sourceComboBox.setValue(null);
I ran into nearly the exact same situation and came across your question while looking for a solution. Fortunately, I came up with a workaround that forces the ComboBoxes to reset. When you reset the data on your pane, instead of doing something like:
sourceComboBox.getSelectionModel().clearSelection();
sourceComboBox.getItems.clear();
do something like this...
parentNode.getChildren().remove(sourceComboBox);
sourceComboBox= new ComboBox(); // do whatever else you need to format your ComboBox
parentNode.add(sourceComboBox);
You'll also need to do a setItems() again on your ComboBox so the new one will be populated. This is not an ideal solution but it seems to be working as I expect the provided clearSelection() method would.
Below is the code you're looking for. It will reset it to whatever index you give in within the parenthesis.
sourceComboBox.setSelectedIndex(0);
Goodluck
Most of the things were giving me an error when I tried them. What worked best for me was to use this
comboBox.getSelectionModel.clearSelection();
This will essentially set the value of your ComboBox to null. Because of this, if you are referring to the value of the ComboBox in another place, it becomes important to check for whether the value of the ComboBox is null using this
if(comboBox.getValue() != null)
//Code segment here
The ComboBox control has not a method like scrollTo(index) of the ListView. So it seems hard to workaround that behavior. You can issue a feature request at JavaFX Jira.
I'm wondering if I can make fake sections in the popup menu:
The rule would be, if the 5th character of the displayed item is different from the 5th char of the previous item in the menu, it has to be highlighted
What do you think?
Thanks!
To achieve this would be a hack.
Normally the items that appear in the popup part of a combo box will be an instantiated data template, and each gets its own data item and has no clue or knowledge of the other items in the list, so you couldn't use a converter or anything else to achieve this behavior.
What you could do though is inject (attach) your own control into the popup part of the combo box, and take over the rendering of the data items. How you do this will depend upon which combo box you are using (i.e. MS or some other vendor's) and would be a whole new question.
Would that be easier if I were to create my own combobox as follow:
a TextBox associated with a Button that when pushed would popup a datagrid in which I could implement this conditional formatting?