How to move a selected item up/down in List Box?

[driplet]

Hi guys:

I am using Borland C++ Builder to make a window application. I need to use a list box to display the items I selected. Besides, I need to chang the order of the selected items in the box. Could any body please give me a clue how I can do this?

Thanks in advance!

Doug

[WolfPack]

How about looking at the facilities offered by the API?

[Ancient Dragon]

I don't think CListBox has a method to move a row from one spot to another. If you want to change the order of the items then I'd probably copy them all into a std::vector, sort the vector however you want, delete everything from the list box, then copy the vector back in the order you want.

[WolfPack]

Yeah. There is no such function in the API too. But I don't know if the list box will flicker if you remove and add the items all at once. Can't you do it by using the <a href="http://msdn2.microsoft.com/en-us/library/ms671439.aspx">LB_SETITEMDATA</a> message? I think it would be much faster.

[Ancient Dragon]

Why would he want to use LB_SETITEMDATA ? That will not change the order of the items that appear in the list box.

[WolfPack]

I don't know. It was just a hunch. I am too lazy to try it and see. Another straightforward way seems to be the use of LB_INSERTSTRING . Since you can specify the index of the position that you want to insert the string to, I think you can use it to change the order of the items.

[Ancient Dragon]

Yes, LB_INSERTSTRING will work if all he wants to do is insert the new item in a specific location.

[WolfPack]

Yeah. But won't deleting an item from it's original location and inserting it in it's new location change the order of the items?

[Ancient Dragon]

Changing the order of the items is what the OP wants to do.

[WolfPack]

This snippet sends the string at zero based index 3, to the position at index 0.

HWND hList = GetDlgItem(hwnd, IDC_LIST);
char buf[100]="";
SendMessage(hList, LB_GETTEXT, (WPARAM)3, (LPARAM)buf);
SendMessage(hList, LB_DELETESTRING, 3, 0);
SendMessage(hList, LB_INSERTSTRING, 0, (WPARAM)buf);

The original order of 0 1 2 3 4 5 will endup with 3 0 1 2 4 5