Question

Hello everyone I’ve been trying to put some objects in an ASP.NET list box but it’s just not working.

I do have an overridden ToString method so I can’t understand why this statement won’t work.
Here’s the code that I use:

for (int i = 0; i < fitnessClassList.Count(); i++)
{
    lbDisplayItems.Items.Add(fClassList.getFClass(i));
}

And the errors that I get:

Error   2   Argument 1: cannot convert from 
                    'FitClassManage' to 
                    'System.Web.UI.WebControls.ListItem'    

Error   1   The best overloaded method match for 
                    'System.Web.UI.WebControls.ListItemCollection.Add(System.Web.UI.WebControls.ListItem)' 
                    has some invalid arguments

Answer 1

The ASP.NET ListBox is not like the WinForms ListBox. You cannot add any object to him. Its item collection (ListItemCollection) is limited to ListItem (so you can’t add your business objects relying on ToString() for visualization).

Use this code:

ListItem listItem = new ListItem(fitnessClassList.getFitnessClass(i).ToString());
lbDisplayItems.Items.Add(listItem);

Do not forget that if you’ll use that ListItem you won’t have the object but its display name (the result of ToString()). See the link about the ListItem for more details.

As alternative you may set the DataSource of the ListView to your fitnessClassList (if it supports that in any way, see this overview on MSDN).