如何在下拉列表中插入项目作为最后一个选项

Question

I know to add an item as the first item, I use:

ddlTest.Items.Insert(0, new ListItem("---New First Item---", "-1"));

I tried -1 as the index but then I didn't even see the item. How to I add an item as the last item in the list without knowing its index number (because the dropdown is populated from a database)?

Answer 1

to add to the LAST position, just add to the list as

ddlTest.Items.Add(new ListItem("---New First Item---", "-1"));

as it will append to the last place by default.

Answer 2

您可以使用列表的大小或长度作为索引，因为长度等于最后一个位置加一。

Answer 3

You can easily do that by adding first all the items and after that, add one based on the index. You know that once your items are in the list.

Here's some code:

// Fill dropdownlist with data from database.
int index = ddlTest.Items.Count;

// You don't need to add or subtract one, because count is starting from 1, while the index starts from 0. 

ddlTest.Items.Insert(index, 0, new ListItem("--- New First Item---", "-1");

I believe that this should work.

Answer 4

Remove the 0 from your Add method. It will automatically detect that the item has to be added at the end.

ddlTest.Items.Add(new ListItem("---New First Item---", "-1"));

Answer 5

Try this one

dropDownList.Items.Add(new ListItem("AddNew","AddNew"));

ref: http://www.aspsnippets.com/Articles/Programmatically-add-items-to-DropDownList-on-Button-Click-in-ASPNet-using-C-and-VBNet.aspx