This seems trivial but I'm having difficulty.
A user selects an item in a dropdown and this creates a little checkmark next to the item.
I want to deselect it in my code and remove that checkmark.
Any ideas?
You can change which item is selected with Dropdown.value. At-lease, one item must be selected.
I want to deselect the item selected. Restore it back to it's original
state.
Get the original item in the Start or Awake function:
public Dropdown dropDown;
private int originalState;
void Awake()
{
originalState = dropDown.value;
}
When you want to restore it back, restore to that value you saved:
void restoreDropDown()
{
dropDown.value = originalState;
}
Unfortunately original state of a dropdown is dropdown.value = -1 and there is no way resetting it once modified. It is always greater than 0 once modified, even if you assign -1 to it.
The only workaround is to create a prefab of Dropdown and Destroy & Instantiate it from prefab when resetting. In this case you need to create all the listeners dynamically from the code which renders all editor assignments of a Dropdown useless. You need to use an initializer script.
Related
I am using Objectlistview in my WFA to create a chekedlistbox.
I want to have a button called "Select all" that the user can click on it and all the rows are selected just by one click.
I have been using the following code which works and all the checkboxes will be selected
private void btnSelectallModule_Click(object sender, EventArgs e)
{
foreach (ListViewItem item in dataListView1.Items)
{
item.Checked = true;
}
}
The problem is that when I check all the items using this button then I hover over each item it will be unchecked automatically without even clicking on that item, which is so weird because I did not intend to do that in the code.
Does anyone know what is going on and how can I fix this?
Thanks
In general do NOT manipulate the ListViewItem objects when working with ObjectListView.
There is a Method dataListView1.CheckAll() that will do exactly what you are trying to do - check all items. Using that method will properly set the internal check states of the OLV control and prevent them from getting visually unchecked when the view refreshes (when hovering the mouse over items).
I'm using ObjectListView with C# and .Net 4.0. I wrote code that reloads the listview and then re-selects the last selected index.
The re-selection code is quite simple:
olvListView.SelectedIndex = i;
This appears to work, because the item is selected. However, if I then click the up or down arrow, the selection jumps up to the second row (no matter what row I selected), suggesting that the selection was actually set on the first row, no matter what was the value of i.
What am I doing wrong here?
The underlying ListView Control distinguishes between 'selection' and 'focus'.
olvListView.SelectedIndex = i; changes the selection but not the focus. But the focused row is the one that the keyboard input relates to.
Either change the focus the as well
olvListView.SelectedIndex = i;
olvListView.FocusedItem = olvListView.SelectedItems[0];
or call
olvListView.SelectObject(aModelObject);
The second solution would be the preferred way to select an item when working with OLV, however you say you "wrote code that reloads the listview", so the reference to the original item is probably different. Maybe you should just refresh the items that changed, instead of reloading everything. That way you could preserve the selection.
Example if your olv have datasource from "class_z.list" and foreach have only one result.
foreach(class_z a in class_z.list.Where(x=>x.id==id_value))
{
olv.SelectedObject = z;
}
I have got a radio button list and based on selection of the radio button list , the drop-downs will populate. Important thing is here the radiobutton list is set to autopostback=true.
And also when i move to next page by button click, And when i come back. Drop down button not able to maintain state. It is losing values. It is important for me to maintain state until i reach the last page. How can i approach this problem. I have used sessions but was not successful. Could you tell me how to implement sessions.
hi #Newyork167 this will not work as he mentioned above that "based on selection of the radio button list , the drop-downs will populate." so you have to store the "RadioButtonList" Selected value and accordingly fillDropDownlist Values and set selected after returning back to the page.
Ok. As per my understanding you need to save a page state so that when you come back then you get the page in previous state where you left. So to do this you have two ways.
1. Before jumping to next page, store everything in session like "Radiobutton selected value", dropdown selected value and other settings if any.
2. Pass these values "Radiobutton selected value", "dropdown selected value" and other if any as the query string and when you coming back then read the same query string.
In either way when you will come back then you will have the previous data. In the page_load event, just check whether you have that data or not. If yes then populate your controls with previous data else populate your controls for first load.
Here is some link for your reference.
http://www.codeproject.com/Articles/5876/Passing-variables-between-pages-using-QueryString
Passing Session[] and Request[] to Methods in C#
If you want to use sessions, you could check the session variable with all of the values of the list
if(Session["selectedList"] != Null){
var check = Session["selectedList"].ToString();
foreach(ListItem item in yourList.Items){
if(item.Value.Equals(check))
// set it as selected
}
}
For storing, when you click the button
Session["selectedList"] = yourList.SelectedValue;
You could also use the indexes instead of the values. You can also create a session variable for each dropdown/radiobuttonlist and you just make a loop for each.
UPDATE
Thanks to Shekhar for pointing this out. You need to go through all of the lists that you want to store and save them with these loops, not just the dropdowns. Then, you need to restore the radio button values, rebind the dropdowns, and then set the selected item for each.
I have an arraylist which contain objects of my own class. I want to fetch the object from the array list which has the index = selectedindex of listview.
I tried this :
TrackInformation t=(TrackInformation) SongList[listView1.SelectedIndices[0]];
TrackInformation is my class and SongList is an ArrayList of type TrackInformation.
listview1 does not allow multiple indices selection so I want the first element of the SelectedIndices collection.
I am getting ArgumentOutOfRangeException and it says value of '0' is not valid for 'index'.
Put this line before your code -
if(listView1.SelectedIndices.Count > 0)
{
TrackInformation t=(TrackInformation) SongList[listView1.SelectedIndices[0]];
}
The ListView.SelectedIndexChanged event has a quirk that bombs your code. When you start your program, no item is selected. Click an item and SelectedIndexChanged fires, no problem. Now click another item and the event fires twice. First to let you know, unhelpfully, that the first item is unselected. Then again to tell you that the new item is selected. That first event is going to make you index an empty array, kaboom. RV1987's snippet prevents this.
The error is because listView1.SelectedIndices is empty, do you have a row selected?
you probable want to wrap in a test
ListView.SelectedIndexCollection selected=listView1.SelectedIndicies;
if (selected.Count==0) {
// code for no items selected
} else {
TrackInformation t=(TrackInformation) SongList[selected[0]];
// rest of code to deal with t
}
I don't know if the title express what I want. I have a ListBox in WPF where I generate many elements. When I click on a element while still generating I want my selected item to not move down the list, so I cannot see it anymore, I want to stay in the exact position where I click on it.
If this is possible, can someone point some ideas on how to do it in C#?
Thanks.
Assuming that this is even a good idea and that you are using winforms
Step 1:
Determine the index of the selected item in the source.
Step 2:
When your adding items to the ListBox split the ListBox at the index where the item previously was insert the item at that point, then add on the remainder of the items, while making sure that you've removed the item if it is now elsewhere in the list.
Code:
//Let's assume that you know how to get the position of the item when it is clicked and save the
//item to a variable called OriginalItem
public void PutTheItemInTheSameSpot()
{
var listboxitems = (List<Integer>)YourListBox.DataSource;
var originalClikedItem = OriginalItem;
var topPart = new List<Integer>();
for (i = 0; i < itemPosition; i++)
{
topPart.Add(listboxItems[i]);
}
topPart.Add(originalClickedItem);
var bottomPart = listboxitems.Remove(toppart);
YourListBox.DataSource = toppart.AddRange(bottomPart);
}
Saw your edit about it being WPF
The could should work in idea.
Just a thought: you could try having your view respond to an event whenever an item is added to your ListBox. In the event handler, you could force the selected item to scroll into view presumably keeping it in the current "viewable" position:
listBox.ScrollIntoView(listBox.SelectedItem);
I've never tried this before so it may or may not produce the desired affect?