dcsimg

Multiple/Single Selection ListBox Control

WEBINAR:
On-Demand

Desktop-as-a-Service Designed for Any Cloud ? Nutanix Frame


I find it quite irritating that one cannot change the style of a CListBox from single to multiple and back dynamically. After plenty of searching the most common solution I found was to place two ListBox controls, one set to Single selection and the other to multiple. The user then populates the two with the same data and does the hide and show dance as required. This is too frustrating.

The SRListBox class is implemented by taking a multiple selection listbox that can be made to behave like a single select listbox. In the single select mode I simply unselect any other selections made. The SRListBox provides the user with a function ( SetSingleSelect(const bool& single) ) to toggle between single and multiple selection.

In addition to this simple implementation I added and array of class SRCBAndLBItemArray. This class simply holds pointers to all items currently selected. This saves me having to go through the painful routine of repeating the code below each time I need my selections.

	int numberSelected = GetSelCount();
	if (numberSelected>0) 
	{
		int *selIndex = new int[numberSelected];
		GetSelItems( numberSelected, selIndex );
		for (int i=0; i < numberSelected; i++) 
		{
			blah....
		}
	}

The SRCBAndLBItemArray gets populated each time the SRListBox::UpdateData() function gets called (perhaps I should have given this function another name). I call this function from the DoDataExchange(CDataExchange* pDX) function of parent window and from the OnSelectionChange message handler. (this is key, without it the SRCBAndLBItemArray does not get populated). Perhaps someone can suggest a better mechanism.

The CListBoxExDlg::OnSelchangeList1() function in the sample code displays the use of the SRListBox data retrieval.

Download demo project - 27 KB



This article was originally published on January 24th, 1999

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date