Crash when typing in UltraComboEditor

Jon posted over 16 years ago

We're getting a fairly regular crash when using the UltraComboEditor. The error seems to happen when you select the combo box and then hit letter keys to select items in the list. We have DropDownStyle set to DropDownList and DropDownListWidth set to -1, other than that we took all the defaults. Here is the stack trace that we're getting:

System.NullReferenceException: Object reference not set to an instance of an object.
   at Infragistics.Win.ValueListItem.DoesTextMatch(String testString, Boolean partial)
   at Infragistics.Win.ValueListItemsCollection.GetItemFromDisplayText(Int32& lastValueListIndex, String displayText, Int32 beginAtIndex, Boolean partial)
   at Infragistics.Win.ValueList.Infragistics.Win.IValueList.GetValue(String text, Int32& index, Int32 beginAtIndex, Boolean partial)
   at Infragistics.Win.EditorWithCombo.ProcessAlphaNumericChar(Char keyChar)
   at Infragistics.Win.EditorWithCombo.OnOwnerKeyPress(KeyPressEventArgs e)
   at Infragistics.Win.EmbeddableEditorBase.ProcessOwnerKeyPress(Object sender, KeyPressEventArgs e)
   at Infragistics.Win.EmbeddableEditorOwnerBase.RaiseKeyPress(KeyPressEventArgs e)
   at Infragistics.Win.UltraWinEditors.UltraComboEditor.OnKeyPress(KeyPressEventArgs e)
   at System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m)
   at System.Windows.Forms.Control.ProcessKeyMessage(Message& m)
   at System.Windows.Forms.Control.WmKeyChar(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

37774

Matt Snyder posted over 16 years ago in reply to Scott

I still can't reproduce this issue even in this scenario. You should definitely make sure you have the latest hotfix.
-Matt
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Scott posted over 16 years ago in reply to Matt Snyder

Both the display and value members have to be null for the error to occur. The stack trace shows it then will try to do a string comparison, and that's where it fails...
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37774

Matt Snyder posted over 16 years ago in reply to Jon

I'm still not able to reproduce this issue. I tried binding the UltraComboEditor to a datatable where the DisplayMember column has a null value in one of the rows. When I tried typing a letter, there was no unhandled exception. Dropping down the list, the row with the null DisplayMember cell had its ValueMember shown instead.
Make sure that you have downloaded the latest hotfix. If this doesn't help, I would contact Developer Support with a small sample so that they can see if this has already been fixed.
-Matt
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Jon posted over 16 years ago in reply to Scott

This is what we've noticed too. I don't think it should be blowing up because of the null value though.
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Scott posted over 16 years ago in reply to Matt Snyder

The issue centers around having a row in the datasource with null member values. This results in a blank row shown in the combobox, but the comparison logic fails since it's a null item being compared to a keystroke letter (string) value...
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