alex_blokha said:

Unable to update the data value: Object of type 'System.DBNull' cannot be converted to type 'System.Nullable`1[System.Decimal]'.

This is occurring because, by default, WinGrid assumes that a "null" value is stored in the underlying data source as DBNull.Value.  A Nullable Decimal field doesn't know what to do with this kind of a value.

To address this, set the Nullable property on the corresponding WinGrid column to "Nothing".  This will store an actual null value ("null" in C#, "Nothing" in VB.NET) whenever the cell's value would be null.  A Nullable Decimal field knows what to do with this kind of a "null' value.

alex_blokha,

I've discussed this behavior in more detail with our developers, and we'd like to take a closer look to see if we can handle this situation in a more automatic fashion.

I'm passing the information on this thread to Developer Support, who will create a support case for you.

In the meantime, you should still be able to set the Nullable property of the column appropriate to what the underlying data source expects.

I'm bumping into this issue as well.  My case is a little more convoluted... there's an UltraCombo being used as the EditorControl.

Any ideas on how I should set up the data in my combo to allow the user to empty out a cell?  Is it as easy as adding a list item that will map an empty string to the correct type of Null?

Thanks

john_m,

john_m said:

Is it as easy as adding a list item that will map an empty string to the correct type of Null?

Typically, this is correct.  As you imply when you say "the correct type of Null," the corresponding column in the underlying data source of your grid must accept some type of null value.