OutOfMemoryException - Too many items in the combo box

OutOfMemoryException - Too many items in the combo box by Gaiii

Closed

as Won't Fix Help for as Won't Fix

Type:	Bug
ID:	417533
Opened:	2/24/2009 8:12:39 AM
Access Restriction:	Public

Workaround(s)

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User(s) can reproduce this bug

Hi,
Couldn't find an existing KB for this issue:

I'm trying to add a couple of items to the Combobox.Items collection and I receive the error described in the title.

The reason is that each object I'm trying to add is an instance of a class that overrides the 'ToString' method and in some cases the method returns null.

The thing is, that the implementation of ComboBox.NativeAdd look like this:

private int NativeAdd(object item) {
            Debug.Assert(IsHandleCreated, "Shouldn't be calling Native methods before the handle is created.");
            int insertIndex = (int)SendMessage(NativeMethods.CB_ADDSTRING, 0, GetItemText(item));
            if (insertIndex < 0) {
                throw new OutOfMemoryException(SR.GetString(SR.ComboBoxItemOverflow));
            }
            return insertIndex;
        }

You can see that is assumes that if the item could not be added it is a memory related issue which in may case, not correct.

I'm using VS2008 SP1, .NET framework 3.5 sp1.

Cheers,
Gai.

Details (expand)

English

.NET Framework 3.5 SP1

Windows XP Professional

English

create a winforms project in VS with a similar code:

public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
MyComboboxItem item1 = new MyComboboxItem { Text = "Some text" };
MyComboboxItem item2 = new MyComboboxItem();

comboBox1.Items.Add(item1);
comboBox1.Items.Add(item2);
}
}

public class MyComboboxItem
{
public string Text { get; set; }

public override string ToString()
{
return Text;
// return Text ?? string.Empty;
}
}

OutOfMemoryException is thrown with the message: "Too many items in the combo box"

NullReferenceException?!

0 attachments

Thanks for your feedback on the .NET Framework!

We are able to reproduce the bug that you reported and consider rolling in a fix to this issue in next release if resources/schedule allow us.

Many customers have found it useful to discuss issues like this in the forums (http://forums.microsoft.com/msdn/default.aspx?siteid=1) where Microsoft and other members of the community can suggest workarounds.

Please keep the feedback comming.

Thanks,
UIFx Team