ThereHasToBeABetterWay.cs

// sourcePngs is a ListBox with property Items (ListItemCollection)
// A custom list of strings in the end (custom to eto, not to me)
var pngs = sourcePngs.Items;

var temp = new string[pngs.Count];
for (var i = 0; i < temp.Length; i++)
	temp[i] = pngs[i].Text;