Is there any property to remove the first (and empty) item in a combobox with style DropDownList ? In other words, I would like to choose the default selected item for a combobox.
I know i can validate the selected item with code, but i want to avoid showing message boxes to the user.
Set the comboBox.SelectedIndex property to 0 to set the selection to the first item in the combobox.
You should set the Text or SelectedIndex or SelectedValue property. In this way the combobox updates the text that's is showing and removes the first empty item (that actually is not a real item).
Related
Am developing a windows application in C#.
The user has to select some listed values in combo box. Those values will be added to Database. When the same user login and select the combo box, already selected values should be visible but shouldn't be get selected....
I referred various websites. All stating to change the colour of Existing values....But it is not enough. I need to disable the values... Is there any options to do it.
Note : Am populating the combo-box items from a database table.
You can set ComboBox.SelectedIndex = -1 for your desired value;
The code is not tested but something like this will help you
if (combobox.selectedIndex == (Index of your value))
{
combobox.selectedIndex = -1;
}
In this way if you try to choose that item it will set selected index to -1 and you will not able to choose that item.
The following link might be helpful for you
Create WinForms ComboBox with non-selectable items
While biding values from db set the selectable property true or false and in the selectedindexchanged event set the selectedindex of the item to -1.
Don't forget to mark it as answer if it is helpful for you.
Note: Before doing this make sure that it is required to show the items. If it is not required just filter them and bind the remaining values.
I have a DataGridView where there is a cell which is a DataGridViewComboCell. Each DataGridViewComboCell is bound to a unique copy of a BindingList. When I remove an item from the binding list the comboboxes remove the entry I had removed from the bindinglist.
However, if that value is selected it stays as the selected item in the cell.
I tried doing a datagridview.refresh(), but it still didn't help. It is getting called from a tool strip menu item
// _contractLists is List<BindingList<String>> which is the datasource for a datagridviewcombobox
List<String> removedList = new List<string>();
_contractSelForm.ShowDialog();
_contractSelForm.GetandClearRemovedContracts(ref removedList);
foreach (BindingList<String> contractList in _contractLists)
{
// remove deleted favorites
foreach (string contract_name in removedList)
{
contractList.Remove(contract_name);
}
}
dataGridView1.Refresh();
dataGridView1.EndEdit();
Couple of things to note/look at:
1) You shouldn't need to call EndEdit after Refresh. If it needs to be called, you should call it before Refresh.
2) If your comboboxes have a DropDownStyle of DropDown, then I this is expected behavior.
From the MSDN documentation:
If you set the DropDownStyle property to DropDown, you can type any value in the editable area of the ComboBox.
To change this, either change the DropDownStyle to DropDownList or manually clear the value in code after removing the items.
In my project i have used four number of dropdownlists in a single form.
when im selecting an item from the 1st dropdownlist,the dropdownlist2 has to display the items that matches the selected item from dropdowmlist1.
Please clear my doubt.,
Use the SelectedIndexChanged-event on the first dropdownlist. Everytime the user selects a different item in the dropdownlist, this event is fired. In the method body you can now react to the change and filter the items of the second dropdownlist to match the selected item of the first dropdownlist. You can either do that manually in a loop or use LINQ (Enumerable.Select).
first of all its called a combobox.
Implement the OnSelectedItemChanged event from the combobox to fill the 2nd combobox
linky
I've got a wpf listbox that is bound to a datatable. At some times, I want to programmaticly change the selection of the listbox. I know the text of the item I want to select. But it doesn't work to set the listbox1.SelectedItem to the text I want because the type of the SelectedItem is System.Data.DataRowView.
If I have the text I want to select and the DataRow that I want to select, what is the easiest way select the associated row in the list box?
Search through your DataSet and find the appropriate DataRow. Then set SelectedItem to that DataRow.
If you know the text, then it would be:
ListBox1.SelectedValue = ListBox1.Items.FindByText("Two").Value;
You can also use the SelectedIndex property to set the selected value by 0-based index.
The ListBox control (both in Forms and WebControls) has a SelectedValue property that:
"Gets the value of the selected item in the list control, or selects the item in the list control that contains the specified value."
You could use this to select the item based on it's value, typically a unique key.
More info from MSDN:
System.Windows.Forms.ListControl.SelectedValue
System.Web.UI.WebControls.ListControl.SelectedValue
I have set a list of items in a combobox, but when I debug the application, I have to select an item from the drop down to display an item by default. Is there a property? that you can set so that the combobox itemindex will always begin at 0 meaning the first item in the list at startup of the application?
this.comboBox1.SelectedIndex = 0;
You are gonna want to use the SelectedIndex attribute.
The SelectedItem property can only be read.
Using the SelectedText and SelectedValue Properties will change the Text and Value not which one is selected