开发者

Most succinct way to convert ListBox.items to a generic list

I am using C# and targeting the .NET Framework 3.5. I'm looking for a small, succinct and efficient piece of code to copy all of the items in a ListBox to a List<String> (Generic List).

At the moment I have something similar to the below code:

        List<String> myOtherList =  new List<String>();
        // Populate our colCriteria with the selected columns.

        foreach (String strCol in lbMyListBox.Items)
        {
            myOtherList.Ad开发者_高级运维d(strCol);
        }

Which works, of course, but I can't help but get the feeling that there must be a better way of doing this with some of the newer language features. I was thinking of something like the List.ConvertAll method but this only applies to Generic Lists and not ListBox.ObjectCollection collections.


A bit of LINQ should do it:-

 var myOtherList = lbMyListBox.Items.Cast<String>().ToList();

Of course you can modify the Type parameter of the Cast to whatever type you have stored in the Items property.


The following will do it (using Linq):

List<string> list = lbMyListBox.Items.OfType<string>().ToList();

The OfType call will ensure that only items in the listbox's items that are strings are used.

Using Cast, if any of the the items are not strings, you will get an exception.


How about this:

List<string> myOtherList = (from l in lbMyListBox.Items.Cast<ListItem>() select l.Value).ToList();


What about:

myOtherList.AddRange(lbMyListBox.Items);

EDIT based on comments and DavidGouge's answer:

myOtherList.AddRange(lbMyListBox.Items.Select(item => ((ListItem)item).Value));


You don't need more. You get List of all values from Listbox

private static List<string> GetAllElements(ListBox chkList)
        {
            return chkList.Items.Cast<ListItem>().Select(x => x.Value).ToList<string>();
        }
0

上一篇:

下一篇:

精彩评论

暂无评论...
验证码 换一张
取 消

最新问答

问答排行榜